PX4-Autopilot/src/modules/ekf2/EKF2.cpp

/****************************************************************************
 *
 *   Copyright (c) 2015-2022 PX4 Development Team. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
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 *    distribution.
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 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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#include "EKF2.hpp"

using namespace time_literals;
using math::constrain;
using matrix::Eulerf;
using matrix::Quatf;
using matrix::Vector3f;

pthread_mutex_t ekf2_module_mutex = PTHREAD_MUTEX_INITIALIZER;
static px4::atomic<EKF2 *> _objects[EKF2_MAX_INSTANCES] {};
#if !defined(CONSTRAINED_FLASH)
static px4::atomic<EKF2Selector *> _ekf2_selector {nullptr};
#endif // !CONSTRAINED_FLASH

EKF2::EKF2(bool multi_mode, const px4::wq_config_t &config, bool replay_mode):
	ModuleParams(nullptr),
	ScheduledWorkItem(MODULE_NAME, config),
	_replay_mode(replay_mode && !multi_mode),
	_multi_mode(multi_mode),
	_instance(multi_mode ? -1 : 0),
	_attitude_pub(multi_mode ? ORB_ID(estimator_attitude) : ORB_ID(vehicle_attitude)),
	_local_position_pub(multi_mode ? ORB_ID(estimator_local_position) : ORB_ID(vehicle_local_position)),
	_global_position_pub(multi_mode ? ORB_ID(estimator_global_position) : ORB_ID(vehicle_global_position)),
	_odometry_pub(multi_mode ? ORB_ID(estimator_odometry) : ORB_ID(vehicle_odometry)),
	_wind_pub(multi_mode ? ORB_ID(estimator_wind) : ORB_ID(wind)),
	_params(_ekf.getParamHandle()),
	_param_ekf2_predict_us(_params->filter_update_interval_us),
	_param_ekf2_mag_delay(_params->mag_delay_ms),
	_param_ekf2_baro_delay(_params->baro_delay_ms),
	_param_ekf2_gps_delay(_params->gps_delay_ms),
	_param_ekf2_of_delay(_params->flow_delay_ms),
	_param_ekf2_rng_delay(_params->range_delay_ms),
	_param_ekf2_asp_delay(_params->airspeed_delay_ms),
	_param_ekf2_ev_delay(_params->ev_delay_ms),
	_param_ekf2_avel_delay(_params->auxvel_delay_ms),
	_param_ekf2_gyr_noise(_params->gyro_noise),
	_param_ekf2_acc_noise(_params->accel_noise),
	_param_ekf2_gyr_b_noise(_params->gyro_bias_p_noise),
	_param_ekf2_acc_b_noise(_params->accel_bias_p_noise),
	_param_ekf2_mag_e_noise(_params->mage_p_noise),
	_param_ekf2_mag_b_noise(_params->magb_p_noise),
	_param_ekf2_wind_nsd(_params->wind_vel_nsd),
	_param_ekf2_terr_noise(_params->terrain_p_noise),
	_param_ekf2_terr_grad(_params->terrain_gradient),
	_param_ekf2_gps_v_noise(_params->gps_vel_noise),
	_param_ekf2_gps_p_noise(_params->gps_pos_noise),
	_param_ekf2_noaid_noise(_params->pos_noaid_noise),
	_param_ekf2_baro_noise(_params->baro_noise),
	_param_ekf2_baro_gate(_params->baro_innov_gate),
	_param_ekf2_gnd_eff_dz(_params->gnd_effect_deadzone),
	_param_ekf2_gnd_max_hgt(_params->gnd_effect_max_hgt),
	_param_ekf2_gps_p_gate(_params->gps_pos_innov_gate),
	_param_ekf2_gps_v_gate(_params->gps_vel_innov_gate),
	_param_ekf2_tas_gate(_params->tas_innov_gate),
	_param_ekf2_head_noise(_params->mag_heading_noise),
	_param_ekf2_mag_noise(_params->mag_noise),
	_param_ekf2_eas_noise(_params->eas_noise),
	_param_ekf2_beta_gate(_params->beta_innov_gate),
	_param_ekf2_beta_noise(_params->beta_noise),
	_param_ekf2_mag_decl(_params->mag_declination_deg),
	_param_ekf2_hdg_gate(_params->heading_innov_gate),
	_param_ekf2_mag_gate(_params->mag_innov_gate),
	_param_ekf2_decl_type(_params->mag_declination_source),
	_param_ekf2_mag_type(_params->mag_fusion_type),
	_param_ekf2_mag_acclim(_params->mag_acc_gate),
	_param_ekf2_mag_yawlim(_params->mag_yaw_rate_gate),
	_param_ekf2_gps_check(_params->gps_check_mask),
	_param_ekf2_req_eph(_params->req_hacc),
	_param_ekf2_req_epv(_params->req_vacc),
	_param_ekf2_req_sacc(_params->req_sacc),
	_param_ekf2_req_nsats(_params->req_nsats),
	_param_ekf2_req_pdop(_params->req_pdop),
	_param_ekf2_req_hdrift(_params->req_hdrift),
	_param_ekf2_req_vdrift(_params->req_vdrift),
	_param_ekf2_aid_mask(_params->fusion_mode),
	_param_ekf2_hgt_mode(_params->height_sensor_ref),
	_param_ekf2_terr_mask(_params->terrain_fusion_mode),
	_param_ekf2_noaid_tout(_params->valid_timeout_max),
	_param_ekf2_rng_noise(_params->range_noise),
	_param_ekf2_rng_sfe(_params->range_noise_scaler),
	_param_ekf2_rng_gate(_params->range_innov_gate),
	_param_ekf2_min_rng(_params->rng_gnd_clearance),
	_param_ekf2_rng_pitch(_params->rng_sens_pitch),
	_param_ekf2_rng_aid(_params->range_aid),
	_param_ekf2_rng_a_vmax(_params->max_vel_for_range_aid),
	_param_ekf2_rng_a_hmax(_params->max_hagl_for_range_aid),
	_param_ekf2_rng_a_igate(_params->range_aid_innov_gate),
	_param_ekf2_rng_qlty_t(_params->range_valid_quality_s),
	_param_ekf2_rng_k_gate(_params->range_kin_consistency_gate),
	_param_ekf2_evv_gate(_params->ev_vel_innov_gate),
	_param_ekf2_evp_gate(_params->ev_pos_innov_gate),
	_param_ekf2_of_n_min(_params->flow_noise),
	_param_ekf2_of_n_max(_params->flow_noise_qual_min),
	_param_ekf2_of_qmin(_params->flow_qual_min),
	_param_ekf2_of_gate(_params->flow_innov_gate),
	_param_ekf2_imu_pos_x(_params->imu_pos_body(0)),
	_param_ekf2_imu_pos_y(_params->imu_pos_body(1)),
	_param_ekf2_imu_pos_z(_params->imu_pos_body(2)),
	_param_ekf2_gps_pos_x(_params->gps_pos_body(0)),
	_param_ekf2_gps_pos_y(_params->gps_pos_body(1)),
	_param_ekf2_gps_pos_z(_params->gps_pos_body(2)),
	_param_ekf2_rng_pos_x(_params->rng_pos_body(0)),
	_param_ekf2_rng_pos_y(_params->rng_pos_body(1)),
	_param_ekf2_rng_pos_z(_params->rng_pos_body(2)),
	_param_ekf2_of_pos_x(_params->flow_pos_body(0)),
	_param_ekf2_of_pos_y(_params->flow_pos_body(1)),
	_param_ekf2_of_pos_z(_params->flow_pos_body(2)),
	_param_ekf2_ev_pos_x(_params->ev_pos_body(0)),
	_param_ekf2_ev_pos_y(_params->ev_pos_body(1)),
	_param_ekf2_ev_pos_z(_params->ev_pos_body(2)),
	_param_ekf2_arsp_thr(_params->arsp_thr),
	_param_ekf2_tau_vel(_params->vel_Tau),
	_param_ekf2_tau_pos(_params->pos_Tau),
	_param_ekf2_gbias_init(_params->switch_on_gyro_bias),
	_param_ekf2_abias_init(_params->switch_on_accel_bias),
	_param_ekf2_angerr_init(_params->initial_tilt_err),
	_param_ekf2_abl_lim(_params->acc_bias_lim),
	_param_ekf2_abl_acclim(_params->acc_bias_learn_acc_lim),
	_param_ekf2_abl_gyrlim(_params->acc_bias_learn_gyr_lim),
	_param_ekf2_abl_tau(_params->acc_bias_learn_tc),
	_param_ekf2_drag_noise(_params->drag_noise),
	_param_ekf2_bcoef_x(_params->bcoef_x),
	_param_ekf2_bcoef_y(_params->bcoef_y),
	_param_ekf2_mcoef(_params->mcoef),
	_param_ekf2_aspd_max(_params->max_correction_airspeed),
	_param_ekf2_pcoef_xp(_params->static_pressure_coef_xp),
	_param_ekf2_pcoef_xn(_params->static_pressure_coef_xn),
	_param_ekf2_pcoef_yp(_params->static_pressure_coef_yp),
	_param_ekf2_pcoef_yn(_params->static_pressure_coef_yn),
	_param_ekf2_pcoef_z(_params->static_pressure_coef_z),
	_param_ekf2_mag_check(_params->check_mag_strength),
	_param_ekf2_synthetic_mag_z(_params->synthesize_mag_z),
	_param_ekf2_gsf_tas_default(_params->EKFGSF_tas_default)
{
	// advertise expected minimal topic set immediately to ensure logging
	_attitude_pub.advertise();
	_local_position_pub.advertise();

	_estimator_event_flags_pub.advertise();
	_estimator_innovation_test_ratios_pub.advertise();
	_estimator_innovation_variances_pub.advertise();
	_estimator_innovations_pub.advertise();
	_estimator_sensor_bias_pub.advertise();
	_estimator_states_pub.advertise();
	_estimator_status_flags_pub.advertise();
	_estimator_status_pub.advertise();
}

EKF2::~EKF2()
{
	perf_free(_ecl_ekf_update_perf);
	perf_free(_ecl_ekf_update_full_perf);
	perf_free(_msg_missed_imu_perf);
	perf_free(_msg_missed_air_data_perf);
	perf_free(_msg_missed_airspeed_perf);
	perf_free(_msg_missed_distance_sensor_perf);
	perf_free(_msg_missed_gps_perf);
	perf_free(_msg_missed_landing_target_pose_perf);
	perf_free(_msg_missed_magnetometer_perf);
	perf_free(_msg_missed_odometry_perf);
	perf_free(_msg_missed_optical_flow_perf);
}

bool EKF2::multi_init(int imu, int mag)
{
	// advertise all topics to ensure consistent uORB instance numbering
	_ekf2_timestamps_pub.advertise();
	_estimator_baro_bias_pub.advertise();
	_estimator_event_flags_pub.advertise();
	_estimator_gps_status_pub.advertise();
	_estimator_innovation_test_ratios_pub.advertise();
	_estimator_innovation_variances_pub.advertise();
	_estimator_innovations_pub.advertise();
	_estimator_optical_flow_vel_pub.advertise();
	_estimator_sensor_bias_pub.advertise();
	_estimator_states_pub.advertise();
	_estimator_status_flags_pub.advertise();
	_estimator_status_pub.advertise();
	_estimator_visual_odometry_aligned_pub.advertise();
	_yaw_est_pub.advertise();

	_attitude_pub.advertise();
	_local_position_pub.advertise();
	_global_position_pub.advertise();
	_odometry_pub.advertise();
	_wind_pub.advertise();

	bool changed_instance = _vehicle_imu_sub.ChangeInstance(imu) && _magnetometer_sub.ChangeInstance(mag);

	const int status_instance = _estimator_states_pub.get_instance();

	if ((status_instance >= 0) && changed_instance
	    && (_attitude_pub.get_instance() == status_instance)
	    && (_local_position_pub.get_instance() == status_instance)
	    && (_global_position_pub.get_instance() == status_instance)) {

		_instance = status_instance;

		ScheduleNow();
		return true;
	}

	PX4_ERR("publication instance problem: %d att: %d lpos: %d gpos: %d", status_instance,
		_attitude_pub.get_instance(), _local_position_pub.get_instance(), _global_position_pub.get_instance());

	return false;
}

int EKF2::print_status()
{
	PX4_INFO_RAW("ekf2:%d EKF dt: %.4fs, IMU dt: %.4fs, attitude: %d, local position: %d, global position: %d\n",
		     _instance, (double)_ekf.get_dt_ekf_avg(), (double)_ekf.get_dt_imu_avg(), _ekf.attitude_valid(),
		     _ekf.local_position_is_valid(), _ekf.global_position_is_valid());

	perf_print_counter(_ecl_ekf_update_perf);
	perf_print_counter(_ecl_ekf_update_full_perf);
	perf_print_counter(_msg_missed_imu_perf);
	perf_print_counter(_msg_missed_air_data_perf);
	perf_print_counter(_msg_missed_airspeed_perf);
	perf_print_counter(_msg_missed_distance_sensor_perf);
	perf_print_counter(_msg_missed_gps_perf);
	perf_print_counter(_msg_missed_landing_target_pose_perf);
	perf_print_counter(_msg_missed_magnetometer_perf);
	perf_print_counter(_msg_missed_odometry_perf);
	perf_print_counter(_msg_missed_optical_flow_perf);

#if defined(DEBUG_BUILD)
	_ekf.print_status();
#endif // DEBUG_BUILD

	return 0;
}

void EKF2::Run()
{
	if (should_exit()) {
		_sensor_combined_sub.unregisterCallback();
		_vehicle_imu_sub.unregisterCallback();

		return;
	}

	// check for parameter updates
	if (_parameter_update_sub.updated() || !_callback_registered) {
		// clear update
		parameter_update_s pupdate;
		_parameter_update_sub.copy(&pupdate);

		// update parameters from storage
		updateParams();

		_ekf.set_min_required_gps_health_time(_param_ekf2_req_gps_h.get() * 1_s);

		// The airspeed scale factor correcton is only available via parameter as used by the airspeed module
		param_t param_aspd_scale = param_find("ASPD_SCALE_1");

		if (param_aspd_scale != PARAM_INVALID) {
			param_get(param_aspd_scale, &_airspeed_scale_factor);
		}

		// if using baro ensure sensor interval minimum is sufficient to accommodate system averaged baro output
		if (_params->fusion_mode & SensorFusionMask::USE_BARO_HGT) {
			float sens_baro_rate = 0.f;

			if (param_get(param_find("SENS_BARO_RATE"), &sens_baro_rate) == PX4_OK) {
				if (sens_baro_rate > 0) {
					float interval_ms = roundf(1000.f / sens_baro_rate);

					if (PX4_ISFINITE(interval_ms) && (interval_ms > _params->sensor_interval_max_ms)) {
						PX4_DEBUG("updating sensor_interval_max_ms %.3f -> %.3f", (double)_params->sensor_interval_max_ms, (double)interval_ms);
						_params->sensor_interval_max_ms = interval_ms;
					}
				}
			}
		}

		// if using mag ensure sensor interval minimum is sufficient to accommodate system averaged mag output
		if (_params->mag_fusion_type != MagFuseType::NONE) {
			float sens_mag_rate = 0.f;

			if (param_get(param_find("SENS_MAG_RATE"), &sens_mag_rate) == PX4_OK) {
				if (sens_mag_rate > 0) {
					float interval_ms = roundf(1000.f / sens_mag_rate);

					if (PX4_ISFINITE(interval_ms) && (interval_ms > _params->sensor_interval_max_ms)) {
						PX4_DEBUG("updating sensor_interval_max_ms %.3f -> %.3f", (double)_params->sensor_interval_max_ms, (double)interval_ms);
						_params->sensor_interval_max_ms = interval_ms;
					}
				}
			}
		}
	}

	if (!_callback_registered) {
		if (_multi_mode) {
			_callback_registered = _vehicle_imu_sub.registerCallback();

		} else {
			_callback_registered = _sensor_combined_sub.registerCallback();
		}

		if (!_callback_registered) {
			ScheduleDelayed(10_ms);
			return;
		}
	}

	if (_vehicle_command_sub.updated()) {
		vehicle_command_s vehicle_command;

		if (_vehicle_command_sub.update(&vehicle_command)) {
			if (vehicle_command.command == vehicle_command_s::VEHICLE_CMD_SET_GPS_GLOBAL_ORIGIN) {
				double latitude = vehicle_command.param5;
				double longitude = vehicle_command.param6;
				float altitude = vehicle_command.param7;

				if (_ekf.setEkfGlobalOrigin(latitude, longitude, altitude)) {
					// Validate the ekf origin status.
					uint64_t origin_time {};
					_ekf.getEkfGlobalOrigin(origin_time, latitude, longitude, altitude);
					PX4_INFO("%d - New NED origin (LLA): %3.10f, %3.10f, %4.3f\n",
						 _instance, latitude, longitude, static_cast<double>(altitude));

				} else {
					PX4_ERR("%d - Failed to set new NED origin (LLA): %3.10f, %3.10f, %4.3f\n",
						_instance, latitude, longitude, static_cast<double>(altitude));
				}
			}
		}
	}

	bool imu_updated = false;
	imuSample imu_sample_new {};

	hrt_abstime imu_dt = 0; // for tracking time slip later

	if (_multi_mode) {
		const unsigned last_generation = _vehicle_imu_sub.get_last_generation();
		vehicle_imu_s imu;
		imu_updated = _vehicle_imu_sub.update(&imu);

		if (imu_updated && (_vehicle_imu_sub.get_last_generation() != last_generation + 1)) {
			perf_count(_msg_missed_imu_perf);
		}

		if (imu_updated) {
			imu_sample_new.time_us = imu.timestamp_sample;
			imu_sample_new.delta_ang_dt = imu.delta_angle_dt * 1.e-6f;
			imu_sample_new.delta_ang = Vector3f{imu.delta_angle};
			imu_sample_new.delta_vel_dt = imu.delta_velocity_dt * 1.e-6f;
			imu_sample_new.delta_vel = Vector3f{imu.delta_velocity};

			if (imu.delta_velocity_clipping > 0) {
				imu_sample_new.delta_vel_clipping[0] = imu.delta_velocity_clipping & vehicle_imu_s::CLIPPING_X;
				imu_sample_new.delta_vel_clipping[1] = imu.delta_velocity_clipping & vehicle_imu_s::CLIPPING_Y;
				imu_sample_new.delta_vel_clipping[2] = imu.delta_velocity_clipping & vehicle_imu_s::CLIPPING_Z;
			}

			imu_dt = imu.delta_angle_dt;

			if ((_device_id_accel == 0) || (_device_id_gyro == 0)) {
				_device_id_accel = imu.accel_device_id;
				_device_id_gyro = imu.gyro_device_id;
				_accel_calibration_count = imu.accel_calibration_count;
				_gyro_calibration_count = imu.gyro_calibration_count;

			} else {
				if ((imu.accel_calibration_count != _accel_calibration_count)
				    || (imu.accel_device_id != _device_id_accel)) {

					PX4_DEBUG("%d - resetting accelerometer bias", _instance);
					_device_id_accel = imu.accel_device_id;

					_ekf.resetAccelBias();
					_accel_calibration_count = imu.accel_calibration_count;

					// reset bias learning
					_accel_cal = {};
				}

				if ((imu.gyro_calibration_count != _gyro_calibration_count)
				    || (imu.gyro_device_id != _device_id_gyro)) {

					PX4_DEBUG("%d - resetting rate gyro bias", _instance);
					_device_id_gyro = imu.gyro_device_id;

					_ekf.resetGyroBias();
					_gyro_calibration_count = imu.gyro_calibration_count;

					// reset bias learning
					_gyro_cal = {};
				}
			}
		}

	} else {
		const unsigned last_generation = _sensor_combined_sub.get_last_generation();
		sensor_combined_s sensor_combined;
		imu_updated = _sensor_combined_sub.update(&sensor_combined);

		if (imu_updated && (_sensor_combined_sub.get_last_generation() != last_generation + 1)) {
			perf_count(_msg_missed_imu_perf);
		}

		if (imu_updated) {
			imu_sample_new.time_us = sensor_combined.timestamp;
			imu_sample_new.delta_ang_dt = sensor_combined.gyro_integral_dt * 1.e-6f;
			imu_sample_new.delta_ang = Vector3f{sensor_combined.gyro_rad} * imu_sample_new.delta_ang_dt;
			imu_sample_new.delta_vel_dt = sensor_combined.accelerometer_integral_dt * 1.e-6f;
			imu_sample_new.delta_vel = Vector3f{sensor_combined.accelerometer_m_s2} * imu_sample_new.delta_vel_dt;

			if (sensor_combined.accelerometer_clipping > 0) {
				imu_sample_new.delta_vel_clipping[0] = sensor_combined.accelerometer_clipping & sensor_combined_s::CLIPPING_X;
				imu_sample_new.delta_vel_clipping[1] = sensor_combined.accelerometer_clipping & sensor_combined_s::CLIPPING_Y;
				imu_sample_new.delta_vel_clipping[2] = sensor_combined.accelerometer_clipping & sensor_combined_s::CLIPPING_Z;
			}

			imu_dt = sensor_combined.gyro_integral_dt;

			if (sensor_combined.accel_calibration_count != _accel_calibration_count) {

				PX4_DEBUG("%d - resetting accelerometer bias", _instance);

				_ekf.resetAccelBias();
				_accel_calibration_count = sensor_combined.accel_calibration_count;

				// reset bias learning
				_accel_cal = {};
			}

			if (sensor_combined.gyro_calibration_count != _gyro_calibration_count) {

				PX4_DEBUG("%d - resetting rate gyro bias", _instance);

				_ekf.resetGyroBias();
				_gyro_calibration_count = sensor_combined.gyro_calibration_count;

				// reset bias learning
				_gyro_cal = {};
			}
		}

		if (_sensor_selection_sub.updated() || (_device_id_accel == 0 || _device_id_gyro == 0)) {
			sensor_selection_s sensor_selection;

			if (_sensor_selection_sub.copy(&sensor_selection)) {
				if (_device_id_accel != sensor_selection.accel_device_id) {

					_device_id_accel = sensor_selection.accel_device_id;

					_ekf.resetAccelBias();

					// reset bias learning
					_accel_cal = {};
				}

				if (_device_id_gyro != sensor_selection.gyro_device_id) {

					_device_id_gyro = sensor_selection.gyro_device_id;

					_ekf.resetGyroBias();

					// reset bias learning
					_gyro_cal = {};
				}
			}
		}
	}

	if (imu_updated) {
		const hrt_abstime now = imu_sample_new.time_us;

		// push imu data into estimator
		_ekf.setIMUData(imu_sample_new);
		PublishAttitude(now); // publish attitude immediately (uses quaternion from output predictor)

		// integrate time to monitor time slippage
		if (_start_time_us > 0) {
			_integrated_time_us += imu_dt;
			_last_time_slip_us = (imu_sample_new.time_us - _start_time_us) - _integrated_time_us;

		} else {
			_start_time_us = imu_sample_new.time_us;
			_last_time_slip_us = 0;
		}

		// update all other topics if they have new data
		if (_status_sub.updated()) {
			vehicle_status_s vehicle_status;

			if (_status_sub.copy(&vehicle_status)) {
				const bool is_fixed_wing = (vehicle_status.vehicle_type == vehicle_status_s::VEHICLE_TYPE_FIXED_WING);

				// only fuse synthetic sideslip measurements if conditions are met
				_ekf.set_fuse_beta_flag(is_fixed_wing && (_param_ekf2_fuse_beta.get() == 1));

				// let the EKF know if the vehicle motion is that of a fixed wing (forward flight only relative to wind)
				_ekf.set_is_fixed_wing(is_fixed_wing);

				_preflt_checker.setVehicleCanObserveHeadingInFlight(vehicle_status.vehicle_type !=
						vehicle_status_s::VEHICLE_TYPE_ROTARY_WING);
			}
		}

		if (_vehicle_land_detected_sub.updated()) {
			vehicle_land_detected_s vehicle_land_detected;

			if (_vehicle_land_detected_sub.copy(&vehicle_land_detected)) {

				_ekf.set_vehicle_at_rest(vehicle_land_detected.at_rest);

				if (vehicle_land_detected.in_ground_effect) {
					_ekf.set_gnd_effect();
				}

				const bool was_in_air = _ekf.control_status_flags().in_air;
				const bool in_air = !vehicle_land_detected.landed;

				if (!was_in_air && in_air) {
					// takeoff
					_ekf.set_in_air_status(true);

					// reset learned sensor calibrations on takeoff
					_accel_cal = {};
					_gyro_cal = {};
					_mag_cal = {};

					_preflt_checker.reset();

				} else if (was_in_air && !in_air) {
					// landed
					_ekf.set_in_air_status(false);
				}
			}
		}

		// ekf2_timestamps (using 0.1 ms relative timestamps)
		ekf2_timestamps_s ekf2_timestamps {
			.timestamp = now,
			.airspeed_timestamp_rel = ekf2_timestamps_s::RELATIVE_TIMESTAMP_INVALID,
			.distance_sensor_timestamp_rel = ekf2_timestamps_s::RELATIVE_TIMESTAMP_INVALID,
			.optical_flow_timestamp_rel = ekf2_timestamps_s::RELATIVE_TIMESTAMP_INVALID,
			.vehicle_air_data_timestamp_rel = ekf2_timestamps_s::RELATIVE_TIMESTAMP_INVALID,
			.vehicle_magnetometer_timestamp_rel = ekf2_timestamps_s::RELATIVE_TIMESTAMP_INVALID,
			.visual_odometry_timestamp_rel = ekf2_timestamps_s::RELATIVE_TIMESTAMP_INVALID,
		};

		UpdateAirspeedSample(ekf2_timestamps);
		UpdateAuxVelSample(ekf2_timestamps);
		UpdateBaroSample(ekf2_timestamps);
		UpdateFlowSample(ekf2_timestamps);
		UpdateGpsSample(ekf2_timestamps);
		UpdateMagSample(ekf2_timestamps);
		UpdateRangeSample(ekf2_timestamps);

		vehicle_odometry_s ev_odom;
		const bool new_ev_odom = UpdateExtVisionSample(ekf2_timestamps, ev_odom);

		// run the EKF update and output
		const hrt_abstime ekf_update_start = hrt_absolute_time();

		if (_ekf.update()) {
			perf_set_elapsed(_ecl_ekf_update_full_perf, hrt_elapsed_time(&ekf_update_start));

			PublishLocalPosition(now);
			PublishOdometry(now);
			PublishGlobalPosition(now);
			PublishWindEstimate(now);

			// publish status/logging messages
			PublishBaroBias(now);
			PublishEventFlags(now);
			PublishGpsStatus(now);
			PublishInnovations(now);
			PublishInnovationTestRatios(now);
			PublishInnovationVariances(now);
			PublishOpticalFlowVel(now);
			PublishStates(now);
			PublishStatus(now);
			PublishStatusFlags(now);
			PublishYawEstimatorStatus(now);

			UpdateAccelCalibration(now);
			UpdateGyroCalibration(now);
			UpdateMagCalibration(now);
			PublishSensorBias(now);

			PublishAidSourceStatus(now);

		} else {
			// ekf no update
			perf_set_elapsed(_ecl_ekf_update_perf, hrt_elapsed_time(&ekf_update_start));
		}

		// publish external visual odometry after fixed frame alignment if new odometry is received
		if (new_ev_odom) {
			PublishOdometryAligned(now, ev_odom);
		}

		// publish ekf2_timestamps
		_ekf2_timestamps_pub.publish(ekf2_timestamps);
	}

	// re-schedule as backup timeout
	ScheduleDelayed(100_ms);
}

void EKF2::PublishAidSourceStatus(const hrt_abstime &timestamp)
{
	// airspeed
	PublishAidSourceStatus(_ekf.aid_src_airspeed(), _status_airspeed_pub_last, _estimator_aid_src_airspeed_pub);

	// baro height
	PublishAidSourceStatus(_ekf.aid_src_baro_hgt(), _status_baro_hgt_pub_last, _estimator_aid_src_baro_hgt_pub);

	// RNG height
	PublishAidSourceStatus(_ekf.aid_src_rng_hgt(), _status_rng_hgt_pub_last, _estimator_aid_src_rng_hgt_pub);

	// fake position
	PublishAidSourceStatus(_ekf.aid_src_fake_pos(), _status_fake_pos_pub_last, _estimator_aid_src_fake_pos_pub);

	// EV yaw
	PublishAidSourceStatus(_ekf.aid_src_ev_yaw(), _status_ev_yaw_pub_last, _estimator_aid_src_ev_yaw_pub);

	// GNSS yaw/velocity/position
	PublishAidSourceStatus(_ekf.aid_src_gnss_yaw(), _status_gnss_yaw_pub_last, _estimator_aid_src_gnss_yaw_pub);
	PublishAidSourceStatus(_ekf.aid_src_gnss_vel(), _status_gnss_vel_pub_last, _estimator_aid_src_gnss_vel_pub);
	PublishAidSourceStatus(_ekf.aid_src_gnss_pos(), _status_gnss_pos_pub_last, _estimator_aid_src_gnss_pos_pub);

	// mag heading
	PublishAidSourceStatus(_ekf.aid_src_mag_heading(), _status_mag_heading_pub_last, _estimator_aid_src_mag_heading_pub);

	// mag 3d
	PublishAidSourceStatus(_ekf.aid_src_mag(), _status_mag_pub_last, _estimator_aid_src_mag_pub);

	// aux velocity
	PublishAidSourceStatus(_ekf.aid_src_aux_vel(), _status_aux_vel_pub_last, _estimator_aid_src_aux_vel_pub);
}

void EKF2::PublishAttitude(const hrt_abstime &timestamp)
{
	if (_ekf.attitude_valid()) {
		// generate vehicle attitude quaternion data
		vehicle_attitude_s att;
		att.timestamp_sample = timestamp;
		const Quatf q{_ekf.calculate_quaternion()};
		q.copyTo(att.q);

		_ekf.get_quat_reset(&att.delta_q_reset[0], &att.quat_reset_counter);
		att.timestamp = _replay_mode ? timestamp : hrt_absolute_time();
		_attitude_pub.publish(att);

	}  else if (_replay_mode) {
		// in replay mode we have to tell the replay module not to wait for an update
		// we do this by publishing an attitude with zero timestamp
		vehicle_attitude_s att{};
		_attitude_pub.publish(att);
	}
}

void EKF2::PublishBaroBias(const hrt_abstime &timestamp)
{
	if (_device_id_baro != 0) {
		const BiasEstimator::status &status = _ekf.getBaroBiasEstimatorStatus();

		if (fabsf(status.bias - _last_baro_bias_published) > 0.001f) {
			estimator_baro_bias_s baro_bias{};
			baro_bias.timestamp_sample = _ekf.get_baro_sample_delayed().time_us;
			baro_bias.baro_device_id = _device_id_baro;
			baro_bias.bias = status.bias;
			baro_bias.bias_var = status.bias_var;
			baro_bias.innov = status.innov;
			baro_bias.innov_var = status.innov_var;
			baro_bias.innov_test_ratio = status.innov_test_ratio;
			baro_bias.timestamp = _replay_mode ? timestamp : hrt_absolute_time();
			_estimator_baro_bias_pub.publish(baro_bias);

			_last_baro_bias_published = status.bias;
		}
	}
}

void EKF2::PublishEventFlags(const hrt_abstime &timestamp)
{
	// information events
	uint32_t information_events = _ekf.information_event_status().value;
	bool information_event_updated = false;

	if (information_events != 0) {
		information_event_updated = true;
		_filter_information_event_changes++;
	}

	// warning events
	uint32_t warning_events = _ekf.warning_event_status().value;
	bool warning_event_updated = false;

	if (warning_events != 0) {
		warning_event_updated = true;
		_filter_warning_event_changes++;
	}

	if (information_event_updated || warning_event_updated) {
		estimator_event_flags_s event_flags{};
		event_flags.timestamp_sample = _ekf.get_imu_sample_delayed().time_us;

		event_flags.information_event_changes           = _filter_information_event_changes;
		event_flags.gps_checks_passed                   = _ekf.information_event_flags().gps_checks_passed;
		event_flags.reset_vel_to_gps                    = _ekf.information_event_flags().reset_vel_to_gps;
		event_flags.reset_vel_to_flow                   = _ekf.information_event_flags().reset_vel_to_flow;
		event_flags.reset_vel_to_vision                 = _ekf.information_event_flags().reset_vel_to_vision;
		event_flags.reset_vel_to_zero                   = _ekf.information_event_flags().reset_vel_to_zero;
		event_flags.reset_pos_to_last_known             = _ekf.information_event_flags().reset_pos_to_last_known;
		event_flags.reset_pos_to_gps                    = _ekf.information_event_flags().reset_pos_to_gps;
		event_flags.reset_pos_to_vision                 = _ekf.information_event_flags().reset_pos_to_vision;
		event_flags.starting_gps_fusion                 = _ekf.information_event_flags().starting_gps_fusion;
		event_flags.starting_vision_pos_fusion          = _ekf.information_event_flags().starting_vision_pos_fusion;
		event_flags.starting_vision_vel_fusion          = _ekf.information_event_flags().starting_vision_vel_fusion;
		event_flags.starting_vision_yaw_fusion          = _ekf.information_event_flags().starting_vision_yaw_fusion;
		event_flags.yaw_aligned_to_imu_gps              = _ekf.information_event_flags().yaw_aligned_to_imu_gps;
		event_flags.reset_hgt_to_baro                   = _ekf.information_event_flags().reset_hgt_to_baro;
		event_flags.reset_hgt_to_gps                    = _ekf.information_event_flags().reset_hgt_to_gps;
		event_flags.reset_hgt_to_rng                    = _ekf.information_event_flags().reset_hgt_to_rng;
		event_flags.reset_hgt_to_ev                     = _ekf.information_event_flags().reset_hgt_to_ev;

		event_flags.warning_event_changes               = _filter_warning_event_changes;
		event_flags.gps_quality_poor                    = _ekf.warning_event_flags().gps_quality_poor;
		event_flags.gps_fusion_timout                   = _ekf.warning_event_flags().gps_fusion_timout;
		event_flags.gps_data_stopped                    = _ekf.warning_event_flags().gps_data_stopped;
		event_flags.gps_data_stopped_using_alternate    = _ekf.warning_event_flags().gps_data_stopped_using_alternate;
		event_flags.height_sensor_timeout               = _ekf.warning_event_flags().height_sensor_timeout;
		event_flags.stopping_navigation                 = _ekf.warning_event_flags().stopping_mag_use;
		event_flags.invalid_accel_bias_cov_reset        = _ekf.warning_event_flags().invalid_accel_bias_cov_reset;
		event_flags.bad_yaw_using_gps_course            = _ekf.warning_event_flags().bad_yaw_using_gps_course;
		event_flags.stopping_mag_use                    = _ekf.warning_event_flags().stopping_mag_use;
		event_flags.vision_data_stopped                 = _ekf.warning_event_flags().vision_data_stopped;
		event_flags.emergency_yaw_reset_mag_stopped     = _ekf.warning_event_flags().emergency_yaw_reset_mag_stopped;
		event_flags.emergency_yaw_reset_gps_yaw_stopped = _ekf.warning_event_flags().emergency_yaw_reset_gps_yaw_stopped;

		event_flags.timestamp = _replay_mode ? timestamp : hrt_absolute_time();
		_estimator_event_flags_pub.update(event_flags);

		_last_event_flags_publish = event_flags.timestamp;

		_ekf.clear_information_events();
		_ekf.clear_warning_events();

	} else if ((_last_event_flags_publish != 0) && (timestamp >= _last_event_flags_publish + 1_s)) {
		// continue publishing periodically
		_estimator_event_flags_pub.get().timestamp = _replay_mode ? timestamp : hrt_absolute_time();
		_estimator_event_flags_pub.update();
		_last_event_flags_publish = _estimator_event_flags_pub.get().timestamp;
	}
}

void EKF2::PublishGlobalPosition(const hrt_abstime &timestamp)
{
	if (_ekf.global_position_is_valid()) {
		const Vector3f position{_ekf.getPosition()};

		// generate and publish global position data
		vehicle_global_position_s global_pos;
		global_pos.timestamp_sample = timestamp;

		// Position of local NED origin in GPS / WGS84 frame
		_ekf.global_origin().reproject(position(0), position(1), global_pos.lat, global_pos.lon);

		float delta_xy[2];
		_ekf.get_posNE_reset(delta_xy, &global_pos.lat_lon_reset_counter);

		global_pos.alt = -position(2) + _ekf.getEkfGlobalOriginAltitude(); // Altitude AMSL in meters
		global_pos.alt_ellipsoid = filter_altitude_ellipsoid(global_pos.alt);

		// global altitude has opposite sign of local down position
		float delta_z;
		uint8_t z_reset_counter;
		_ekf.get_posD_reset(&delta_z, &z_reset_counter);
		global_pos.delta_alt = -delta_z;

		_ekf.get_ekf_gpos_accuracy(&global_pos.eph, &global_pos.epv);

		if (_ekf.isTerrainEstimateValid()) {
			// Terrain altitude in m, WGS84
			global_pos.terrain_alt = _ekf.getEkfGlobalOriginAltitude() - _ekf.getTerrainVertPos();
			global_pos.terrain_alt_valid = true;

		} else {
			global_pos.terrain_alt = NAN;
			global_pos.terrain_alt_valid = false;
		}

		global_pos.dead_reckoning = _ekf.control_status_flags().inertial_dead_reckoning
					    || _ekf.control_status_flags().wind_dead_reckoning;
		global_pos.timestamp = _replay_mode ? timestamp : hrt_absolute_time();
		_global_position_pub.publish(global_pos);
	}
}

void EKF2::PublishGpsStatus(const hrt_abstime &timestamp)
{
	const hrt_abstime timestamp_sample = _ekf.get_gps_sample_delayed().time_us;

	if (timestamp_sample == _last_gps_status_published) {
		return;
	}

	estimator_gps_status_s estimator_gps_status{};
	estimator_gps_status.timestamp_sample = timestamp_sample;

	estimator_gps_status.position_drift_rate_horizontal_m_s = _ekf.gps_horizontal_position_drift_rate_m_s();
	estimator_gps_status.position_drift_rate_vertical_m_s   = _ekf.gps_vertical_position_drift_rate_m_s();
	estimator_gps_status.filtered_horizontal_speed_m_s      = _ekf.gps_filtered_horizontal_velocity_m_s();

	estimator_gps_status.checks_passed = _ekf.gps_checks_passed();

	estimator_gps_status.check_fail_gps_fix          = _ekf.gps_check_fail_status_flags().fix;
	estimator_gps_status.check_fail_min_sat_count    = _ekf.gps_check_fail_status_flags().nsats;
	estimator_gps_status.check_fail_max_pdop         = _ekf.gps_check_fail_status_flags().pdop;
	estimator_gps_status.check_fail_max_horz_err     = _ekf.gps_check_fail_status_flags().hacc;
	estimator_gps_status.check_fail_max_vert_err     = _ekf.gps_check_fail_status_flags().vacc;
	estimator_gps_status.check_fail_max_spd_err      = _ekf.gps_check_fail_status_flags().sacc;
	estimator_gps_status.check_fail_max_horz_drift   = _ekf.gps_check_fail_status_flags().hdrift;
	estimator_gps_status.check_fail_max_vert_drift   = _ekf.gps_check_fail_status_flags().vdrift;
	estimator_gps_status.check_fail_max_horz_spd_err = _ekf.gps_check_fail_status_flags().hspeed;
	estimator_gps_status.check_fail_max_vert_spd_err = _ekf.gps_check_fail_status_flags().vspeed;

	estimator_gps_status.timestamp = _replay_mode ? timestamp : hrt_absolute_time();
	_estimator_gps_status_pub.publish(estimator_gps_status);


	_last_gps_status_published = timestamp_sample;
}

void EKF2::PublishInnovations(const hrt_abstime &timestamp)
{
	// publish estimator innovation data
	estimator_innovations_s innovations{};
	innovations.timestamp_sample = _ekf.get_imu_sample_delayed().time_us;
	_ekf.getGpsVelPosInnov(innovations.gps_hvel, innovations.gps_vvel, innovations.gps_hpos, innovations.gps_vpos);
	_ekf.getEvVelPosInnov(innovations.ev_hvel, innovations.ev_vvel, innovations.ev_hpos, innovations.ev_vpos);
	_ekf.getBaroHgtInnov(innovations.baro_vpos);
	_ekf.getRngHgtInnov(innovations.rng_vpos);
	_ekf.getAuxVelInnov(innovations.aux_hvel);
	_ekf.getFlowInnov(innovations.flow);
	_ekf.getHeadingInnov(innovations.heading);
	_ekf.getMagInnov(innovations.mag_field);
	_ekf.getDragInnov(innovations.drag);
	_ekf.getAirspeedInnov(innovations.airspeed);
	_ekf.getBetaInnov(innovations.beta);
	_ekf.getHaglInnov(innovations.hagl);
	_ekf.getHaglRateInnov(innovations.hagl_rate);
	// Not yet supported
	innovations.aux_vvel = NAN;

	innovations.timestamp = _replay_mode ? timestamp : hrt_absolute_time();
	_estimator_innovations_pub.publish(innovations);

	// calculate noise filtered velocity innovations which are used for pre-flight checking
	if (!_ekf.control_status_flags().in_air) {
		// TODO: move to run before publications
		_preflt_checker.setUsingGpsAiding(_ekf.control_status_flags().gps);
		_preflt_checker.setUsingFlowAiding(_ekf.control_status_flags().opt_flow);
		_preflt_checker.setUsingEvPosAiding(_ekf.control_status_flags().ev_pos);
		_preflt_checker.setUsingEvVelAiding(_ekf.control_status_flags().ev_vel);

		_preflt_checker.setUsingBaroHgtAiding(_ekf.control_status_flags().baro_hgt);
		_preflt_checker.setUsingGpsHgtAiding(_ekf.control_status_flags().gps_hgt);
		_preflt_checker.setUsingRngHgtAiding(_ekf.control_status_flags().rng_hgt);
		_preflt_checker.setUsingEvHgtAiding(_ekf.control_status_flags().ev_hgt);

		_preflt_checker.update(_ekf.get_imu_sample_delayed().delta_ang_dt, innovations);
	}
}

void EKF2::PublishInnovationTestRatios(const hrt_abstime &timestamp)
{
	// publish estimator innovation test ratio data
	estimator_innovations_s test_ratios{};
	test_ratios.timestamp_sample = _ekf.get_imu_sample_delayed().time_us;
	_ekf.getGpsVelPosInnovRatio(test_ratios.gps_hvel[0], test_ratios.gps_vvel, test_ratios.gps_hpos[0],
				    test_ratios.gps_vpos);
	_ekf.getEvVelPosInnovRatio(test_ratios.ev_hvel[0], test_ratios.ev_vvel, test_ratios.ev_hpos[0], test_ratios.ev_vpos);
	_ekf.getBaroHgtInnovRatio(test_ratios.baro_vpos);
	_ekf.getRngHgtInnovRatio(test_ratios.rng_vpos);
	_ekf.getAuxVelInnovRatio(test_ratios.aux_hvel[0]);
	_ekf.getFlowInnovRatio(test_ratios.flow[0]);
	_ekf.getHeadingInnovRatio(test_ratios.heading);
	_ekf.getMagInnovRatio(test_ratios.mag_field[0]);
	_ekf.getDragInnovRatio(&test_ratios.drag[0]);
	_ekf.getAirspeedInnovRatio(test_ratios.airspeed);
	_ekf.getBetaInnovRatio(test_ratios.beta);
	_ekf.getHaglInnovRatio(test_ratios.hagl);
	_ekf.getHaglRateInnovRatio(test_ratios.hagl_rate);
	// Not yet supported
	test_ratios.aux_vvel = NAN;

	test_ratios.timestamp = _replay_mode ? timestamp : hrt_absolute_time();
	_estimator_innovation_test_ratios_pub.publish(test_ratios);
}

void EKF2::PublishInnovationVariances(const hrt_abstime &timestamp)
{
	// publish estimator innovation variance data
	estimator_innovations_s variances{};
	variances.timestamp_sample = _ekf.get_imu_sample_delayed().time_us;
	_ekf.getGpsVelPosInnovVar(variances.gps_hvel, variances.gps_vvel, variances.gps_hpos, variances.gps_vpos);
	_ekf.getEvVelPosInnovVar(variances.ev_hvel, variances.ev_vvel, variances.ev_hpos, variances.ev_vpos);
	_ekf.getBaroHgtInnovVar(variances.baro_vpos);
	_ekf.getRngHgtInnovVar(variances.rng_vpos);
	_ekf.getAuxVelInnovVar(variances.aux_hvel);
	_ekf.getFlowInnovVar(variances.flow);
	_ekf.getHeadingInnovVar(variances.heading);
	_ekf.getMagInnovVar(variances.mag_field);
	_ekf.getDragInnovVar(variances.drag);
	_ekf.getAirspeedInnovVar(variances.airspeed);
	_ekf.getBetaInnovVar(variances.beta);
	_ekf.getHaglInnovVar(variances.hagl);
	_ekf.getHaglRateInnovVar(variances.hagl_rate);
	// Not yet supported
	variances.aux_vvel = NAN;

	variances.timestamp = _replay_mode ? timestamp : hrt_absolute_time();
	_estimator_innovation_variances_pub.publish(variances);
}

void EKF2::PublishLocalPosition(const hrt_abstime &timestamp)
{
	vehicle_local_position_s lpos;
	// generate vehicle local position data
	lpos.timestamp_sample = timestamp;

	// Position of body origin in local NED frame
	const Vector3f position{_ekf.getPosition()};
	lpos.x = position(0);
	lpos.y = position(1);
	lpos.z = position(2);

	// Velocity of body origin in local NED frame (m/s)
	const Vector3f velocity{_ekf.getVelocity()};
	lpos.vx = velocity(0);
	lpos.vy = velocity(1);
	lpos.vz = velocity(2);

	// vertical position time derivative (m/s)
	lpos.z_deriv = _ekf.getVerticalPositionDerivative();

	// Acceleration of body origin in local frame
	const Vector3f vel_deriv{_ekf.getVelocityDerivative()};
	lpos.ax = vel_deriv(0);
	lpos.ay = vel_deriv(1);
	lpos.az = vel_deriv(2);

	// TODO: better status reporting
	lpos.xy_valid = _ekf.local_position_is_valid();
	lpos.z_valid = !_preflt_checker.hasVertFailed();
	lpos.v_xy_valid = _ekf.local_position_is_valid();
	lpos.v_z_valid = !_preflt_checker.hasVertFailed();

	// Position of local NED origin in GPS / WGS84 frame
	if (_ekf.global_origin_valid()) {
		lpos.ref_timestamp = _ekf.global_origin().getProjectionReferenceTimestamp();
		lpos.ref_lat = _ekf.global_origin().getProjectionReferenceLat(); // Reference point latitude in degrees
		lpos.ref_lon = _ekf.global_origin().getProjectionReferenceLon(); // Reference point longitude in degrees
		lpos.ref_alt = _ekf.getEkfGlobalOriginAltitude();           // Reference point in MSL altitude meters
		lpos.xy_global = true;
		lpos.z_global = true;

	} else {
		lpos.ref_timestamp = 0;
		lpos.ref_lat = static_cast<double>(NAN);
		lpos.ref_lon = static_cast<double>(NAN);
		lpos.ref_alt = NAN;
		lpos.xy_global = false;
		lpos.z_global = false;
	}

	Quatf delta_q_reset;
	_ekf.get_quat_reset(&delta_q_reset(0), &lpos.heading_reset_counter);

	lpos.heading = Eulerf(_ekf.getQuaternion()).psi();
	lpos.delta_heading = Eulerf(delta_q_reset).psi();
	lpos.heading_good_for_control = _ekf.isYawFinalAlignComplete();

	// Distance to bottom surface (ground) in meters
	// constrain the distance to ground to _rng_gnd_clearance
	lpos.dist_bottom = math::max(_ekf.getTerrainVertPos() - lpos.z, _param_ekf2_min_rng.get());
	lpos.dist_bottom_valid = _ekf.isTerrainEstimateValid();
	lpos.dist_bottom_sensor_bitfield = _ekf.getTerrainEstimateSensorBitfield();

	_ekf.get_ekf_lpos_accuracy(&lpos.eph, &lpos.epv);
	_ekf.get_ekf_vel_accuracy(&lpos.evh, &lpos.evv);

	// get state reset information of position and velocity
	_ekf.get_posD_reset(&lpos.delta_z, &lpos.z_reset_counter);
	_ekf.get_velD_reset(&lpos.delta_vz, &lpos.vz_reset_counter);
	_ekf.get_posNE_reset(&lpos.delta_xy[0], &lpos.xy_reset_counter);
	_ekf.get_velNE_reset(&lpos.delta_vxy[0], &lpos.vxy_reset_counter);

	lpos.dead_reckoning = _ekf.control_status_flags().inertial_dead_reckoning
			      || _ekf.control_status_flags().wind_dead_reckoning;

	// get control limit information
	_ekf.get_ekf_ctrl_limits(&lpos.vxy_max, &lpos.vz_max, &lpos.hagl_min, &lpos.hagl_max);

	// convert NaN to INFINITY
	if (!PX4_ISFINITE(lpos.vxy_max)) {
		lpos.vxy_max = INFINITY;
	}

	if (!PX4_ISFINITE(lpos.vz_max)) {
		lpos.vz_max = INFINITY;
	}

	if (!PX4_ISFINITE(lpos.hagl_min)) {
		lpos.hagl_min = INFINITY;
	}

	if (!PX4_ISFINITE(lpos.hagl_max)) {
		lpos.hagl_max = INFINITY;
	}

	// publish vehicle local position data
	lpos.timestamp = _replay_mode ? timestamp : hrt_absolute_time();
	_local_position_pub.publish(lpos);
}

void EKF2::PublishOdometry(const hrt_abstime &timestamp)
{
	// generate vehicle odometry data
	vehicle_odometry_s odom;
	odom.timestamp_sample = timestamp;

	// position
	odom.pose_frame = vehicle_odometry_s::POSE_FRAME_NED;
	_ekf.getPosition().copyTo(odom.position);

	// orientation quaternion
	_ekf.getQuaternion().copyTo(odom.q);

	// velocity
	odom.velocity_frame = vehicle_odometry_s::VELOCITY_FRAME_NED;
	_ekf.getVelocity().copyTo(odom.velocity);

	// angular_velocity
	const Vector3f rates{_ekf.get_imu_sample_newest().delta_ang / _ekf.get_imu_sample_newest().delta_ang_dt};
	const Vector3f angular_velocity = rates - _ekf.getGyroBias();
	angular_velocity.copyTo(odom.angular_velocity);

	// velocity covariances
	_ekf.velocity_covariances().diag().copyTo(odom.velocity_variance);

	// position covariances
	_ekf.position_covariances().diag().copyTo(odom.position_variance);

	// orientation covariance
	_ekf.orientation_covariances_euler().diag().copyTo(odom.orientation_variance);

	odom.reset_counter = _ekf.get_quat_reset_count()
			     + _ekf.get_velNE_reset_count() + _ekf.get_velD_reset_count()
			     + _ekf.get_posNE_reset_count() + _ekf.get_posD_reset_count();

	odom.quality = 0;

	// publish vehicle odometry data
	odom.timestamp = _replay_mode ? timestamp : hrt_absolute_time();
	_odometry_pub.publish(odom);
}

void EKF2::PublishOdometryAligned(const hrt_abstime &timestamp, const vehicle_odometry_s &ev_odom)
{
	const Quatf quat_ev2ekf = _ekf.getVisionAlignmentQuaternion(); // rotates from EV to EKF navigation frame
	const Dcmf ev_rot_mat(quat_ev2ekf);

	vehicle_odometry_s aligned_ev_odom{ev_odom};

	// Rotate external position and velocity into EKF navigation frame
	const Vector3f aligned_pos = ev_rot_mat * Vector3f(ev_odom.position);
	aligned_pos.copyTo(aligned_ev_odom.position);

	switch (ev_odom.velocity_frame) {
	case vehicle_odometry_s::VELOCITY_FRAME_BODY_FRD: {
			const Vector3f aligned_vel = Dcmf(_ekf.getQuaternion()) * Vector3f(ev_odom.velocity);
			aligned_vel.copyTo(aligned_ev_odom.velocity);
			break;
		}

	case vehicle_odometry_s::VELOCITY_FRAME_FRD: {
			const Vector3f aligned_vel = ev_rot_mat * Vector3f(ev_odom.velocity);
			aligned_vel.copyTo(aligned_ev_odom.velocity);
			break;
		}
	}

	aligned_ev_odom.velocity_frame = vehicle_odometry_s::VELOCITY_FRAME_NED;

	// Compute orientation in EKF navigation frame
	Quatf ev_quat_aligned = quat_ev2ekf * Quatf(ev_odom.q);
	ev_quat_aligned.normalize();

	ev_quat_aligned.copyTo(aligned_ev_odom.q);

	aligned_ev_odom.timestamp = _replay_mode ? timestamp : hrt_absolute_time();
	_estimator_visual_odometry_aligned_pub.publish(aligned_ev_odom);
}

void EKF2::PublishSensorBias(const hrt_abstime &timestamp)
{
	// estimator_sensor_bias
	const Vector3f gyro_bias{_ekf.getGyroBias()};
	const Vector3f accel_bias{_ekf.getAccelBias()};
	const Vector3f mag_bias{_ekf.getMagBias()};

	// publish at ~1 Hz, or sooner if there's a change
	if ((gyro_bias - _last_gyro_bias_published).longerThan(0.001f)
	    || (accel_bias - _last_accel_bias_published).longerThan(0.001f)
	    || (mag_bias - _last_mag_bias_published).longerThan(0.001f)
	    || (timestamp >= _last_sensor_bias_published + 1_s)) {

		estimator_sensor_bias_s bias{};
		bias.timestamp_sample = _ekf.get_imu_sample_delayed().time_us;

		// take device ids from sensor_selection_s if not using specific vehicle_imu_s
		if (_device_id_gyro != 0) {
			bias.gyro_device_id = _device_id_gyro;
			gyro_bias.copyTo(bias.gyro_bias);
			bias.gyro_bias_limit = math::radians(20.f); // 20 degrees/s see Ekf::constrainStates()
			_ekf.getGyroBiasVariance().copyTo(bias.gyro_bias_variance);
			bias.gyro_bias_valid = true;  // TODO
			bias.gyro_bias_stable = _gyro_cal.cal_available;
			_last_gyro_bias_published = gyro_bias;
		}

		if ((_device_id_accel != 0) && !(_param_ekf2_aid_mask.get() & SensorFusionMask::INHIBIT_ACC_BIAS)) {
			bias.accel_device_id = _device_id_accel;
			accel_bias.copyTo(bias.accel_bias);
			bias.accel_bias_limit = _params->acc_bias_lim;
			_ekf.getAccelBiasVariance().copyTo(bias.accel_bias_variance);
			bias.accel_bias_valid = true;  // TODO
			bias.accel_bias_stable = _accel_cal.cal_available;
			_last_accel_bias_published = accel_bias;
		}

		if (_device_id_mag != 0) {
			bias.mag_device_id = _device_id_mag;
			mag_bias.copyTo(bias.mag_bias);
			bias.mag_bias_limit = 0.5f; // 0.5 Gauss see Ekf::constrainStates()
			_ekf.getMagBiasVariance().copyTo(bias.mag_bias_variance);
			bias.mag_bias_valid = true; // TODO
			bias.mag_bias_stable = _mag_cal.cal_available;
			_last_mag_bias_published = mag_bias;
		}

		bias.timestamp = _replay_mode ? timestamp : hrt_absolute_time();
		_estimator_sensor_bias_pub.publish(bias);

		_last_sensor_bias_published = bias.timestamp;
	}
}

void EKF2::PublishStates(const hrt_abstime &timestamp)
{
	// publish estimator states
	estimator_states_s states;
	states.timestamp_sample = _ekf.get_imu_sample_delayed().time_us;
	states.n_states = Ekf::_k_num_states;
	_ekf.getStateAtFusionHorizonAsVector().copyTo(states.states);
	_ekf.covariances_diagonal().copyTo(states.covariances);
	states.timestamp = _replay_mode ? timestamp : hrt_absolute_time();
	_estimator_states_pub.publish(states);
}

void EKF2::PublishStatus(const hrt_abstime &timestamp)
{
	estimator_status_s status{};
	status.timestamp_sample = _ekf.get_imu_sample_delayed().time_us;

	_ekf.getOutputTrackingError().copyTo(status.output_tracking_error);

	// only report enabled GPS check failures (the param indexes are shifted by 1 bit, because they don't include
	// the GPS Fix bit, which is always checked)
	status.gps_check_fail_flags = _ekf.gps_check_fail_status().value & (((uint16_t)_params->gps_check_mask << 1) | 1);

	status.control_mode_flags = _ekf.control_status().value;
	status.filter_fault_flags = _ekf.fault_status().value;

	uint16_t innov_check_flags_temp = 0;
	_ekf.get_innovation_test_status(innov_check_flags_temp, status.mag_test_ratio,
					status.vel_test_ratio, status.pos_test_ratio,
					status.hgt_test_ratio, status.tas_test_ratio,
					status.hagl_test_ratio, status.beta_test_ratio);

	// Bit mismatch between ecl and Firmware, combine the 2 first bits to preserve msg definition
	// TODO: legacy use only, those flags are also in estimator_status_flags
	status.innovation_check_flags = (innov_check_flags_temp >> 1) | (innov_check_flags_temp & 0x1);

	_ekf.get_ekf_lpos_accuracy(&status.pos_horiz_accuracy, &status.pos_vert_accuracy);
	_ekf.get_ekf_soln_status(&status.solution_status_flags);

	// reset counters
	status.reset_count_vel_ne = _ekf.state_reset_status().velNE_counter;
	status.reset_count_vel_d = _ekf.state_reset_status().velD_counter;
	status.reset_count_pos_ne = _ekf.state_reset_status().posNE_counter;
	status.reset_count_pod_d = _ekf.state_reset_status().posD_counter;
	status.reset_count_quat = _ekf.state_reset_status().quat_counter;

	status.time_slip = _last_time_slip_us * 1e-6f;

	status.pre_flt_fail_innov_heading = _preflt_checker.hasHeadingFailed();
	status.pre_flt_fail_innov_vel_horiz = _preflt_checker.hasHorizVelFailed();
	status.pre_flt_fail_innov_vel_vert = _preflt_checker.hasVertVelFailed();
	status.pre_flt_fail_innov_height = _preflt_checker.hasHeightFailed();
	status.pre_flt_fail_mag_field_disturbed = _ekf.control_status_flags().mag_field_disturbed;

	status.accel_device_id = _device_id_accel;
	status.baro_device_id = _device_id_baro;
	status.gyro_device_id = _device_id_gyro;
	status.mag_device_id = _device_id_mag;

	status.timestamp = _replay_mode ? timestamp : hrt_absolute_time();
	_estimator_status_pub.publish(status);
}

void EKF2::PublishStatusFlags(const hrt_abstime &timestamp)
{
	// publish at ~ 1 Hz (or immediately if filter control status or fault status changes)
	bool update = (timestamp >= _last_status_flags_publish + 1_s);

	// filter control status
	if (_ekf.control_status().value != _filter_control_status) {
		update = true;
		_filter_control_status = _ekf.control_status().value;
		_filter_control_status_changes++;
	}

	// filter fault status
	if (_ekf.fault_status().value != _filter_fault_status) {
		update = true;
		_filter_fault_status = _ekf.fault_status().value;
		_filter_fault_status_changes++;
	}

	// innovation check fail status
	if (_ekf.innov_check_fail_status().value != _innov_check_fail_status) {
		update = true;
		_innov_check_fail_status = _ekf.innov_check_fail_status().value;
		_innov_check_fail_status_changes++;
	}

	if (update) {
		estimator_status_flags_s status_flags{};
		status_flags.timestamp_sample = _ekf.get_imu_sample_delayed().time_us;

		status_flags.control_status_changes   = _filter_control_status_changes;
		status_flags.cs_tilt_align            = _ekf.control_status_flags().tilt_align;
		status_flags.cs_yaw_align             = _ekf.control_status_flags().yaw_align;
		status_flags.cs_gps                   = _ekf.control_status_flags().gps;
		status_flags.cs_opt_flow              = _ekf.control_status_flags().opt_flow;
		status_flags.cs_mag_hdg               = _ekf.control_status_flags().mag_hdg;
		status_flags.cs_mag_3d                = _ekf.control_status_flags().mag_3D;
		status_flags.cs_mag_dec               = _ekf.control_status_flags().mag_dec;
		status_flags.cs_in_air                = _ekf.control_status_flags().in_air;
		status_flags.cs_wind                  = _ekf.control_status_flags().wind;
		status_flags.cs_baro_hgt              = _ekf.control_status_flags().baro_hgt;
		status_flags.cs_rng_hgt               = _ekf.control_status_flags().rng_hgt;
		status_flags.cs_gps_hgt               = _ekf.control_status_flags().gps_hgt;
		status_flags.cs_ev_pos                = _ekf.control_status_flags().ev_pos;
		status_flags.cs_ev_yaw                = _ekf.control_status_flags().ev_yaw;
		status_flags.cs_ev_hgt                = _ekf.control_status_flags().ev_hgt;
		status_flags.cs_fuse_beta             = _ekf.control_status_flags().fuse_beta;
		status_flags.cs_mag_field_disturbed   = _ekf.control_status_flags().mag_field_disturbed;
		status_flags.cs_fixed_wing            = _ekf.control_status_flags().fixed_wing;
		status_flags.cs_mag_fault             = _ekf.control_status_flags().mag_fault;
		status_flags.cs_fuse_aspd             = _ekf.control_status_flags().fuse_aspd;
		status_flags.cs_gnd_effect            = _ekf.control_status_flags().gnd_effect;
		status_flags.cs_rng_stuck             = _ekf.control_status_flags().rng_stuck;
		status_flags.cs_gps_yaw               = _ekf.control_status_flags().gps_yaw;
		status_flags.cs_mag_aligned_in_flight = _ekf.control_status_flags().mag_aligned_in_flight;
		status_flags.cs_ev_vel                = _ekf.control_status_flags().ev_vel;
		status_flags.cs_synthetic_mag_z       = _ekf.control_status_flags().synthetic_mag_z;
		status_flags.cs_vehicle_at_rest       = _ekf.control_status_flags().vehicle_at_rest;
		status_flags.cs_gps_yaw_fault         = _ekf.control_status_flags().gps_yaw_fault;
		status_flags.cs_rng_fault             = _ekf.control_status_flags().rng_fault;
		status_flags.cs_inertial_dead_reckoning = _ekf.control_status_flags().inertial_dead_reckoning;
		status_flags.cs_wind_dead_reckoning     = _ekf.control_status_flags().wind_dead_reckoning;
		status_flags.cs_rng_kin_consistent      = _ekf.control_status_flags().rng_kin_consistent;

		status_flags.fault_status_changes     = _filter_fault_status_changes;
		status_flags.fs_bad_mag_x             = _ekf.fault_status_flags().bad_mag_x;
		status_flags.fs_bad_mag_y             = _ekf.fault_status_flags().bad_mag_y;
		status_flags.fs_bad_mag_z             = _ekf.fault_status_flags().bad_mag_z;
		status_flags.fs_bad_hdg               = _ekf.fault_status_flags().bad_hdg;
		status_flags.fs_bad_mag_decl          = _ekf.fault_status_flags().bad_mag_decl;
		status_flags.fs_bad_airspeed          = _ekf.fault_status_flags().bad_airspeed;
		status_flags.fs_bad_sideslip          = _ekf.fault_status_flags().bad_sideslip;
		status_flags.fs_bad_optflow_x         = _ekf.fault_status_flags().bad_optflow_X;
		status_flags.fs_bad_optflow_y         = _ekf.fault_status_flags().bad_optflow_Y;
		status_flags.fs_bad_vel_n             = _ekf.fault_status_flags().bad_vel_N;
		status_flags.fs_bad_vel_e             = _ekf.fault_status_flags().bad_vel_E;
		status_flags.fs_bad_vel_d             = _ekf.fault_status_flags().bad_vel_D;
		status_flags.fs_bad_pos_n             = _ekf.fault_status_flags().bad_pos_N;
		status_flags.fs_bad_pos_e             = _ekf.fault_status_flags().bad_pos_E;
		status_flags.fs_bad_pos_d             = _ekf.fault_status_flags().bad_pos_D;
		status_flags.fs_bad_acc_bias          = _ekf.fault_status_flags().bad_acc_bias;
		status_flags.fs_bad_acc_vertical      = _ekf.fault_status_flags().bad_acc_vertical;
		status_flags.fs_bad_acc_clipping      = _ekf.fault_status_flags().bad_acc_clipping;

		status_flags.innovation_fault_status_changes = _innov_check_fail_status_changes;
		status_flags.reject_hor_vel                  = _ekf.innov_check_fail_status_flags().reject_hor_vel;
		status_flags.reject_ver_vel                  = _ekf.innov_check_fail_status_flags().reject_ver_vel;
		status_flags.reject_hor_pos                  = _ekf.innov_check_fail_status_flags().reject_hor_pos;
		status_flags.reject_ver_pos                  = _ekf.innov_check_fail_status_flags().reject_ver_pos;
		status_flags.reject_yaw                      = _ekf.innov_check_fail_status_flags().reject_yaw;
		status_flags.reject_airspeed                 = _ekf.innov_check_fail_status_flags().reject_airspeed;
		status_flags.reject_sideslip                 = _ekf.innov_check_fail_status_flags().reject_sideslip;
		status_flags.reject_hagl                     = _ekf.innov_check_fail_status_flags().reject_hagl;
		status_flags.reject_optflow_x                = _ekf.innov_check_fail_status_flags().reject_optflow_X;
		status_flags.reject_optflow_y                = _ekf.innov_check_fail_status_flags().reject_optflow_Y;

		status_flags.timestamp = _replay_mode ? timestamp : hrt_absolute_time();
		_estimator_status_flags_pub.publish(status_flags);

		_last_status_flags_publish = status_flags.timestamp;
	}
}

void EKF2::PublishYawEstimatorStatus(const hrt_abstime &timestamp)
{
	static_assert(sizeof(yaw_estimator_status_s::yaw) / sizeof(float) == N_MODELS_EKFGSF,
		      "yaw_estimator_status_s::yaw wrong size");

	yaw_estimator_status_s yaw_est_test_data;

	if (_ekf.getDataEKFGSF(&yaw_est_test_data.yaw_composite, &yaw_est_test_data.yaw_variance,
			       yaw_est_test_data.yaw,
			       yaw_est_test_data.innov_vn, yaw_est_test_data.innov_ve,
			       yaw_est_test_data.weight)) {

		yaw_est_test_data.yaw_composite_valid = _ekf.isYawEmergencyEstimateAvailable();
		yaw_est_test_data.timestamp_sample = _ekf.get_imu_sample_delayed().time_us;
		yaw_est_test_data.timestamp = _replay_mode ? timestamp : hrt_absolute_time();

		_yaw_est_pub.publish(yaw_est_test_data);
	}
}

void EKF2::PublishWindEstimate(const hrt_abstime &timestamp)
{
	if (_ekf.get_wind_status()) {
		// Publish wind estimate only if ekf declares them valid
		wind_s wind{};
		wind.timestamp_sample = _ekf.get_imu_sample_delayed().time_us;

		const Vector2f wind_vel = _ekf.getWindVelocity();
		const Vector2f wind_vel_var = _ekf.getWindVelocityVariance();
		_ekf.getAirspeedInnov(wind.tas_innov);
		_ekf.getAirspeedInnovVar(wind.tas_innov_var);
		_ekf.getBetaInnov(wind.beta_innov);
		_ekf.getBetaInnovVar(wind.beta_innov_var);

		wind.windspeed_north = wind_vel(0);
		wind.windspeed_east = wind_vel(1);
		wind.variance_north = wind_vel_var(0);
		wind.variance_east = wind_vel_var(1);
		wind.timestamp = _replay_mode ? timestamp : hrt_absolute_time();

		_wind_pub.publish(wind);
	}
}

void EKF2::PublishOpticalFlowVel(const hrt_abstime &timestamp)
{
	if (_ekf.getFlowCompensated().longerThan(0.f)) {
		vehicle_optical_flow_vel_s flow_vel{};
		flow_vel.timestamp_sample = _ekf.get_imu_sample_delayed().time_us;

		_ekf.getFlowVelBody().copyTo(flow_vel.vel_body);
		_ekf.getFlowVelNE().copyTo(flow_vel.vel_ne);

		_ekf.getFlowUncompensated().copyTo(flow_vel.flow_uncompensated_integral);
		_ekf.getFlowCompensated().copyTo(flow_vel.flow_compensated_integral);

		_ekf.getFlowGyro().copyTo(flow_vel.gyro_rate);
		_ekf.getFlowGyroIntegral().copyTo(flow_vel.gyro_rate_integral);

		flow_vel.timestamp = _replay_mode ? timestamp : hrt_absolute_time();

		_estimator_optical_flow_vel_pub.publish(flow_vel);
	}
}

float EKF2::filter_altitude_ellipsoid(float amsl_hgt)
{
	float height_diff = static_cast<float>(_gps_alttitude_ellipsoid) * 1e-3f - amsl_hgt;

	if (_gps_alttitude_ellipsoid_previous_timestamp == 0) {

		_wgs84_hgt_offset = height_diff;
		_gps_alttitude_ellipsoid_previous_timestamp = _gps_time_usec;

	} else if (_gps_time_usec != _gps_alttitude_ellipsoid_previous_timestamp) {

		// apply a 10 second first order low pass filter to baro offset
		float dt = 1e-6f * (_gps_time_usec - _gps_alttitude_ellipsoid_previous_timestamp);
		_gps_alttitude_ellipsoid_previous_timestamp = _gps_time_usec;
		float offset_rate_correction = 0.1f * (height_diff - _wgs84_hgt_offset);
		_wgs84_hgt_offset += dt * constrain(offset_rate_correction, -0.1f, 0.1f);
	}

	return amsl_hgt + _wgs84_hgt_offset;
}

void EKF2::UpdateAirspeedSample(ekf2_timestamps_s &ekf2_timestamps)
{
	// EKF airspeed sample
	// prefer ORB_ID(airspeed_validated) if available, otherwise fallback to raw airspeed ORB_ID(airspeed)
	if (_airspeed_validated_sub.updated()) {
		const unsigned last_generation = _airspeed_validated_sub.get_last_generation();
		airspeed_validated_s airspeed_validated;

		if (_airspeed_validated_sub.update(&airspeed_validated)) {
			if (_msg_missed_airspeed_validated_perf == nullptr) {
				_msg_missed_airspeed_validated_perf = perf_alloc(PC_COUNT, MODULE_NAME": airspeed validated messages missed");

			} else if (_airspeed_validated_sub.get_last_generation() != last_generation + 1) {
				perf_count(_msg_missed_airspeed_validated_perf);
			}

			if (PX4_ISFINITE(airspeed_validated.true_airspeed_m_s)
			    && PX4_ISFINITE(airspeed_validated.calibrated_airspeed_m_s)
			    && (airspeed_validated.calibrated_airspeed_m_s > 0.f)
			   ) {
				airspeedSample airspeed_sample {
					.time_us = airspeed_validated.timestamp,
					.true_airspeed = airspeed_validated.true_airspeed_m_s,
					.eas2tas = airspeed_validated.true_airspeed_m_s / airspeed_validated.calibrated_airspeed_m_s,
				};
				_ekf.setAirspeedData(airspeed_sample);
			}

			_airspeed_validated_timestamp_last = airspeed_validated.timestamp;
		}

	} else if (((ekf2_timestamps.timestamp - _airspeed_validated_timestamp_last) > 3_s) && _airspeed_sub.updated()) {
		// use ORB_ID(airspeed) if ORB_ID(airspeed_validated) is unavailable
		const unsigned last_generation = _airspeed_sub.get_last_generation();
		airspeed_s airspeed;

		if (_airspeed_sub.update(&airspeed)) {
			if (_msg_missed_airspeed_perf == nullptr) {
				_msg_missed_airspeed_perf = perf_alloc(PC_COUNT, MODULE_NAME": airspeed messages missed");

			} else if (_airspeed_sub.get_last_generation() != last_generation + 1) {
				perf_count(_msg_missed_airspeed_perf);
			}

			// The airspeed measurement received via ORB_ID(airspeed) topic has not been corrected
			// for scale factor errors and requires the ASPD_SCALE correction to be applied.
			const float true_airspeed_m_s = airspeed.true_airspeed_m_s * _airspeed_scale_factor;

			if (PX4_ISFINITE(airspeed.true_airspeed_m_s)
			    && PX4_ISFINITE(airspeed.indicated_airspeed_m_s)
			    && (airspeed.indicated_airspeed_m_s > 0.f)
			   ) {
				airspeedSample airspeed_sample {
					.time_us = airspeed.timestamp_sample,
					.true_airspeed = true_airspeed_m_s,
					.eas2tas = airspeed.true_airspeed_m_s / airspeed.indicated_airspeed_m_s,
				};
				_ekf.setAirspeedData(airspeed_sample);
			}

			ekf2_timestamps.airspeed_timestamp_rel = (int16_t)((int64_t)airspeed.timestamp / 100 -
					(int64_t)ekf2_timestamps.timestamp / 100);
		}
	}
}

void EKF2::UpdateAuxVelSample(ekf2_timestamps_s &ekf2_timestamps)
{
	// EKF auxiliary velocity sample
	//  - use the landing target pose estimate as another source of velocity data
	const unsigned last_generation = _landing_target_pose_sub.get_last_generation();
	landing_target_pose_s landing_target_pose;

	if (_landing_target_pose_sub.update(&landing_target_pose)) {
		if (_msg_missed_landing_target_pose_perf == nullptr) {
			_msg_missed_landing_target_pose_perf = perf_alloc(PC_COUNT, MODULE_NAME": landing_target_pose messages missed");

		} else if (_landing_target_pose_sub.get_last_generation() != last_generation + 1) {
			perf_count(_msg_missed_landing_target_pose_perf);
		}

		// we can only use the landing target if it has a fixed position and  a valid velocity estimate
		if (landing_target_pose.is_static && landing_target_pose.rel_vel_valid) {
			// velocity of vehicle relative to target has opposite sign to target relative to vehicle
			auxVelSample auxvel_sample{
				.time_us = landing_target_pose.timestamp,
				.vel = Vector3f{-landing_target_pose.vx_rel, -landing_target_pose.vy_rel, NAN},
				.velVar = Vector3f{landing_target_pose.cov_vx_rel, landing_target_pose.cov_vy_rel, NAN},
			};
			_ekf.setAuxVelData(auxvel_sample);
		}
	}
}

void EKF2::UpdateBaroSample(ekf2_timestamps_s &ekf2_timestamps)
{
	// EKF baro sample
	const unsigned last_generation = _airdata_sub.get_last_generation();
	vehicle_air_data_s airdata;

	if (_airdata_sub.update(&airdata)) {
		if (_msg_missed_air_data_perf == nullptr) {
			_msg_missed_air_data_perf = perf_alloc(PC_COUNT, MODULE_NAME": vehicle_air_data messages missed");

		} else if (_airdata_sub.get_last_generation() != last_generation + 1) {
			perf_count(_msg_missed_air_data_perf);
		}

		bool reset = false;

		// check if barometer has changed
		if (airdata.baro_device_id != _device_id_baro) {
			if (_device_id_baro != 0) {
				PX4_WARN("%d - baro sensor ID changed %" PRIu32 " -> %" PRIu32, _instance, _device_id_baro, airdata.baro_device_id);
			}

			reset = true;

		} else if (airdata.calibration_count > _baro_calibration_count) {
			// existing calibration has changed, reset saved baro bias
			PX4_DEBUG("%d - baro %" PRIu32 " calibration updated, resetting bias", _instance, _device_id_baro);
			reset = true;
		}

		if (reset) {
			// TODO: reset baro ref and bias estimate?
			_device_id_baro = airdata.baro_device_id;
			_baro_calibration_count = airdata.calibration_count;
		}

		_ekf.set_air_density(airdata.rho);

		_ekf.setBaroData(baroSample{airdata.timestamp_sample, airdata.baro_alt_meter});

		_device_id_baro = airdata.baro_device_id;

		ekf2_timestamps.vehicle_air_data_timestamp_rel = (int16_t)((int64_t)airdata.timestamp / 100 -
				(int64_t)ekf2_timestamps.timestamp / 100);
	}
}

bool EKF2::UpdateExtVisionSample(ekf2_timestamps_s &ekf2_timestamps, vehicle_odometry_s &ev_odom)
{
	// EKF external vision sample
	bool new_ev_odom = false;
	const unsigned last_generation = _ev_odom_sub.get_last_generation();

	if (_ev_odom_sub.update(&ev_odom)) {
		if (_msg_missed_odometry_perf == nullptr) {
			_msg_missed_odometry_perf = perf_alloc(PC_COUNT, MODULE_NAME": vehicle_visual_odometry messages missed");

		} else if (_ev_odom_sub.get_last_generation() != last_generation + 1) {
			perf_count(_msg_missed_odometry_perf);
		}

		extVisionSample ev_data{};
		ev_data.pos.setNaN();
		ev_data.vel.setNaN();
		ev_data.quat.setNaN();

		// if error estimates are unavailable, use parameter defined defaults

		// check for valid velocity data
		if (PX4_ISFINITE(ev_odom.velocity[0]) && PX4_ISFINITE(ev_odom.velocity[1]) && PX4_ISFINITE(ev_odom.velocity[2])) {
			bool velocity_valid = true;

			switch (ev_odom.velocity_frame) {
			// case vehicle_odometry_s::VELOCITY_FRAME_NED:
			// 	ev_data.vel_frame = VelocityFrame::LOCAL_FRAME_NED;
			// 	break;

			case vehicle_odometry_s::VELOCITY_FRAME_FRD:
				ev_data.vel_frame = VelocityFrame::LOCAL_FRAME_FRD;
				break;

			case vehicle_odometry_s::VELOCITY_FRAME_BODY_FRD:
				ev_data.vel_frame = VelocityFrame::BODY_FRAME_FRD;
				break;

			default:
				velocity_valid = false;
				break;
			}

			if (velocity_valid) {
				ev_data.vel(0) = ev_odom.velocity[0];
				ev_data.vel(1) = ev_odom.velocity[1];
				ev_data.vel(2) = ev_odom.velocity[2];

				const float evv_noise_var = sq(_param_ekf2_evv_noise.get());

				// velocity measurement error from ev_data or parameters
				if (!_param_ekf2_ev_noise_md.get() &&
				    PX4_ISFINITE(ev_odom.velocity_variance[0]) &&
				    PX4_ISFINITE(ev_odom.velocity_variance[1]) &&
				    PX4_ISFINITE(ev_odom.velocity_variance[2])) {

					ev_data.velVar(0) = fmaxf(evv_noise_var, ev_odom.velocity_variance[0]);
					ev_data.velVar(1) = fmaxf(evv_noise_var, ev_odom.velocity_variance[1]);
					ev_data.velVar(2) = fmaxf(evv_noise_var, ev_odom.velocity_variance[2]);

				} else {
					ev_data.velVar.setAll(evv_noise_var);
				}

				new_ev_odom = true;
			}
		}

		// check for valid position data
		if (PX4_ISFINITE(ev_odom.position[0]) && PX4_ISFINITE(ev_odom.position[1]) && PX4_ISFINITE(ev_odom.position[2])) {

			bool position_valid = true;

			// switch (ev_odom.pose_frame) {
			// case vehicle_odometry_s::POSE_FRAME_NED:
			// 	ev_data.pos_frame = PositionFrame::LOCAL_FRAME_NED;
			// 	break;

			// case vehicle_odometry_s::POSE_FRAME_FRD:
			// 	ev_data.pos_frame = PositionFrame::LOCAL_FRAME_FRD;
			// 	break;

			// default:
			// 	position_valid = false;
			// 	break;
			// }

			if (position_valid) {
				ev_data.pos(0) = ev_odom.position[0];
				ev_data.pos(1) = ev_odom.position[1];
				ev_data.pos(2) = ev_odom.position[2];

				const float evp_noise_var = sq(_param_ekf2_evp_noise.get());

				// position measurement error from ev_data or parameters
				if (!_param_ekf2_ev_noise_md.get() &&
				    PX4_ISFINITE(ev_odom.position_variance[0]) &&
				    PX4_ISFINITE(ev_odom.position_variance[1]) &&
				    PX4_ISFINITE(ev_odom.position_variance[2])
				   ) {
					ev_data.posVar(0) = fmaxf(evp_noise_var, ev_odom.position_variance[0]);
					ev_data.posVar(1) = fmaxf(evp_noise_var, ev_odom.position_variance[1]);
					ev_data.posVar(2) = fmaxf(evp_noise_var, ev_odom.position_variance[2]);

				} else {
					ev_data.posVar.setAll(evp_noise_var);
				}

				new_ev_odom = true;
			}
		}

		// check for valid orientation data
		if ((PX4_ISFINITE(ev_odom.q[0]) && PX4_ISFINITE(ev_odom.q[1])
		     && PX4_ISFINITE(ev_odom.q[2]) && PX4_ISFINITE(ev_odom.q[3]))
		    && ((fabsf(ev_odom.q[0]) > 0.f) || (fabsf(ev_odom.q[1]) > 0.f)
			|| (fabsf(ev_odom.q[2]) > 0.f) || (fabsf(ev_odom.q[3]) > 0.f))
		   ) {
			ev_data.quat = Quatf(ev_odom.q);
			ev_data.quat.normalize();

			// orientation measurement error from ev_data or parameters
			const float eva_noise_var = sq(_param_ekf2_eva_noise.get());

			if (!_param_ekf2_ev_noise_md.get() &&
			    PX4_ISFINITE(ev_odom.orientation_variance[2])
			   ) {
				ev_data.angVar = fmaxf(eva_noise_var, ev_odom.orientation_variance[2]);

			} else {
				ev_data.angVar = eva_noise_var;
			}

			new_ev_odom = true;
		}

		// use timestamp from external computer, clocks are synchronized when using MAVROS
		ev_data.time_us = ev_odom.timestamp_sample;
		ev_data.reset_counter = ev_odom.reset_counter;
		//ev_data.quality = ev_odom.quality;

		if (new_ev_odom)  {
			_ekf.setExtVisionData(ev_data);
		}

		ekf2_timestamps.visual_odometry_timestamp_rel = (int16_t)((int64_t)ev_odom.timestamp / 100 -
				(int64_t)ekf2_timestamps.timestamp / 100);
	}

	return new_ev_odom;
}

bool EKF2::UpdateFlowSample(ekf2_timestamps_s &ekf2_timestamps)
{
	// EKF flow sample
	bool new_optical_flow = false;
	const unsigned last_generation = _vehicle_optical_flow_sub.get_last_generation();
	vehicle_optical_flow_s optical_flow;

	if (_vehicle_optical_flow_sub.update(&optical_flow)) {
		if (_msg_missed_optical_flow_perf == nullptr) {
			_msg_missed_optical_flow_perf = perf_alloc(PC_COUNT, MODULE_NAME": optical_flow messages missed");

		} else if (_vehicle_optical_flow_sub.get_last_generation() != last_generation + 1) {
			perf_count(_msg_missed_optical_flow_perf);
		}

		flowSample flow {
			.time_us = optical_flow.timestamp_sample,
			// NOTE: the EKF uses the reverse sign convention to the flow sensor. EKF assumes positive LOS rate
			// is produced by a RH rotation of the image about the sensor axis.
			.flow_xy_rad = Vector2f{-optical_flow.pixel_flow[0], -optical_flow.pixel_flow[1]},
			.gyro_xyz = Vector3f{-optical_flow.delta_angle[0], -optical_flow.delta_angle[1], -optical_flow.delta_angle[2]},
			.dt = 1e-6f * (float)optical_flow.integration_timespan_us,
			.quality = optical_flow.quality,
		};

		if (PX4_ISFINITE(optical_flow.pixel_flow[0]) &&
		    PX4_ISFINITE(optical_flow.pixel_flow[1]) &&
		    flow.dt < 1) {

			// Save sensor limits reported by the optical flow sensor
			_ekf.set_optical_flow_limits(optical_flow.max_flow_rate, optical_flow.min_ground_distance,
						     optical_flow.max_ground_distance);

			_ekf.setOpticalFlowData(flow);

			new_optical_flow = true;
		}

		// use optical_flow distance as range sample if distance_sensor unavailable
		if (PX4_ISFINITE(optical_flow.distance_m) && ((ekf2_timestamps.timestamp - _last_range_sensor_update) > 1_s)) {

			int8_t quality = static_cast<float>(optical_flow.quality) / static_cast<float>(UINT8_MAX) * 100.f;

			rangeSample range_sample {
				.time_us = optical_flow.timestamp_sample,
				.rng = optical_flow.distance_m,
				.quality = quality,
			};
			_ekf.setRangeData(range_sample);

			// set sensor limits
			_ekf.set_rangefinder_limits(optical_flow.min_ground_distance, optical_flow.max_ground_distance);
		}

		ekf2_timestamps.optical_flow_timestamp_rel = (int16_t)((int64_t)optical_flow.timestamp / 100 -
				(int64_t)ekf2_timestamps.timestamp / 100);
	}

	return new_optical_flow;
}

void EKF2::UpdateGpsSample(ekf2_timestamps_s &ekf2_timestamps)
{
	// EKF GPS message
	const unsigned last_generation = _vehicle_gps_position_sub.get_last_generation();
	sensor_gps_s vehicle_gps_position;

	if (_vehicle_gps_position_sub.update(&vehicle_gps_position)) {
		if (_msg_missed_gps_perf == nullptr) {
			_msg_missed_gps_perf = perf_alloc(PC_COUNT, MODULE_NAME": vehicle_gps_position messages missed");

		} else if (_vehicle_gps_position_sub.get_last_generation() != last_generation + 1) {
			perf_count(_msg_missed_gps_perf);
		}

		gpsMessage gps_msg{
			.time_usec = vehicle_gps_position.timestamp,
			.lat = vehicle_gps_position.lat,
			.lon = vehicle_gps_position.lon,
			.alt = vehicle_gps_position.alt,
			.yaw = vehicle_gps_position.heading,
			.yaw_offset = vehicle_gps_position.heading_offset,
			.fix_type = vehicle_gps_position.fix_type,
			.eph = vehicle_gps_position.eph,
			.epv = vehicle_gps_position.epv,
			.sacc = vehicle_gps_position.s_variance_m_s,
			.vel_m_s = vehicle_gps_position.vel_m_s,
			.vel_ned = Vector3f{
				vehicle_gps_position.vel_n_m_s,
				vehicle_gps_position.vel_e_m_s,
				vehicle_gps_position.vel_d_m_s
			},
			.vel_ned_valid = vehicle_gps_position.vel_ned_valid,
			.nsats = vehicle_gps_position.satellites_used,
			.pdop = sqrtf(vehicle_gps_position.hdop *vehicle_gps_position.hdop
				      + vehicle_gps_position.vdop * vehicle_gps_position.vdop),
		};
		_ekf.setGpsData(gps_msg);

		_gps_time_usec = gps_msg.time_usec;
		_gps_alttitude_ellipsoid = vehicle_gps_position.alt_ellipsoid;
	}
}

void EKF2::UpdateMagSample(ekf2_timestamps_s &ekf2_timestamps)
{
	const unsigned last_generation = _magnetometer_sub.get_last_generation();
	vehicle_magnetometer_s magnetometer;

	if (_magnetometer_sub.update(&magnetometer)) {
		if (_msg_missed_magnetometer_perf == nullptr) {
			_msg_missed_magnetometer_perf = perf_alloc(PC_COUNT, MODULE_NAME": vehicle_magnetometer messages missed");

		} else if (_magnetometer_sub.get_last_generation() != last_generation + 1) {
			perf_count(_msg_missed_magnetometer_perf);
		}

		bool reset = false;

		// check if magnetometer has changed
		if (magnetometer.device_id != _device_id_mag) {
			if (_device_id_mag != 0) {
				PX4_WARN("%d - mag sensor ID changed %" PRIu32 " -> %" PRIu32, _instance, _device_id_mag, magnetometer.device_id);
			}

			reset = true;

		} else if (magnetometer.calibration_count != _mag_calibration_count) {
			// existing calibration has changed, reset saved mag bias
			PX4_DEBUG("%d - mag %" PRIu32 " calibration updated, resetting bias", _instance, _device_id_mag);
			reset = true;
		}

		if (reset) {
			_ekf.resetMagBiasAndYaw();
			_device_id_mag = magnetometer.device_id;
			_mag_calibration_count = magnetometer.calibration_count;

			// reset magnetometer bias learning
			_mag_cal = {};
		}

		_ekf.setMagData(magSample{magnetometer.timestamp_sample, Vector3f{magnetometer.magnetometer_ga}});

		ekf2_timestamps.vehicle_magnetometer_timestamp_rel = (int16_t)((int64_t)magnetometer.timestamp / 100 -
				(int64_t)ekf2_timestamps.timestamp / 100);
	}
}

void EKF2::UpdateRangeSample(ekf2_timestamps_s &ekf2_timestamps)
{
	distance_sensor_s distance_sensor;

	if (_distance_sensor_selected < 0) {

		// only consider distance sensors that have updated within the last 0.1s
		const hrt_abstime timestamp_stale = math::max(ekf2_timestamps.timestamp, 100_ms) - 100_ms;

		if (_distance_sensor_subs.advertised()) {
			for (unsigned i = 0; i < _distance_sensor_subs.size(); i++) {

				if (_distance_sensor_subs[i].update(&distance_sensor)) {
					// only use the first instace which has the correct orientation
					if ((distance_sensor.timestamp != 0) && (distance_sensor.timestamp > timestamp_stale)
					    && (distance_sensor.orientation == distance_sensor_s::ROTATION_DOWNWARD_FACING)) {

						int ndist = orb_group_count(ORB_ID(distance_sensor));

						if (ndist > 1) {
							PX4_INFO("%d - selected distance_sensor:%d (%d advertised)", _instance, i, ndist);
						}

						_distance_sensor_selected = i;
						_last_range_sensor_update = distance_sensor.timestamp;
						_distance_sensor_last_generation = _distance_sensor_subs[_distance_sensor_selected].get_last_generation() - 1;
						break;
					}
				}
			}
		}
	}

	if (_distance_sensor_selected >= 0 && _distance_sensor_subs[_distance_sensor_selected].update(&distance_sensor)) {
		// EKF range sample

		if (_msg_missed_distance_sensor_perf == nullptr) {
			_msg_missed_distance_sensor_perf = perf_alloc(PC_COUNT, MODULE_NAME": distance_sensor messages missed");

		} else if (_distance_sensor_subs[_distance_sensor_selected].get_last_generation() != _distance_sensor_last_generation +
			   1) {
			perf_count(_msg_missed_distance_sensor_perf);
		}

		_distance_sensor_last_generation = _distance_sensor_subs[_distance_sensor_selected].get_last_generation();

		if (distance_sensor.orientation == distance_sensor_s::ROTATION_DOWNWARD_FACING) {
			rangeSample range_sample {
				.time_us = distance_sensor.timestamp,
				.rng = distance_sensor.current_distance,
				.quality = distance_sensor.signal_quality,
			};
			_ekf.setRangeData(range_sample);

			// Save sensor limits reported by the rangefinder
			_ekf.set_rangefinder_limits(distance_sensor.min_distance, distance_sensor.max_distance);

			_last_range_sensor_update = distance_sensor.timestamp;
		}

		ekf2_timestamps.distance_sensor_timestamp_rel = (int16_t)((int64_t)distance_sensor.timestamp / 100 -
				(int64_t)ekf2_timestamps.timestamp / 100);
	}

	if (_last_range_sensor_update < ekf2_timestamps.timestamp - 1_s) {
		// force reselection after timeout
		_distance_sensor_selected = -1;
	}
}

void EKF2::UpdateAccelCalibration(const hrt_abstime &timestamp)
{
	if (_param_ekf2_aid_mask.get() & SensorFusionMask::INHIBIT_ACC_BIAS) {
		_accel_cal.cal_available = false;
		return;
	}

	static constexpr float max_var_allowed = 1e-3f;
	static constexpr float max_var_ratio = 1e2f;

	const Vector3f bias_variance{_ekf.getAccelBiasVariance()};

	// Check if conditions are OK for learning of accelerometer bias values
	// the EKF is operating in the correct mode and there are no filter faults
	if ((_ekf.fault_status().value == 0)
	    && !_ekf.accel_bias_inhibited()
	    && !_preflt_checker.hasHorizFailed() && !_preflt_checker.hasVertFailed()
	    && (_ekf.control_status_flags().baro_hgt || _ekf.control_status_flags().rng_hgt
		|| _ekf.control_status_flags().gps_hgt || _ekf.control_status_flags().ev_hgt)
	    && !_ekf.warning_event_flags().height_sensor_timeout && !_ekf.warning_event_flags().invalid_accel_bias_cov_reset
	    && !_ekf.innov_check_fail_status_flags().reject_ver_pos && !_ekf.innov_check_fail_status_flags().reject_ver_vel
	    && (bias_variance.max() < max_var_allowed) && (bias_variance.max() < max_var_ratio * bias_variance.min())
	   ) {

		if (_accel_cal.last_us != 0) {
			_accel_cal.total_time_us += timestamp - _accel_cal.last_us;

			// consider bias estimates stable when we have accumulated sufficient time
			if (_accel_cal.total_time_us > 30_s) {
				_accel_cal.cal_available = true;
			}
		}

		_accel_cal.last_us = timestamp;

	} else {
		_accel_cal = {};
	}
}

void EKF2::UpdateGyroCalibration(const hrt_abstime &timestamp)
{
	static constexpr float max_var_allowed = 1e-3f;
	static constexpr float max_var_ratio = 1e2f;

	const Vector3f bias_variance{_ekf.getGyroBiasVariance()};

	// Check if conditions are OK for learning of gyro bias values
	// the EKF is operating in the correct mode and there are no filter faults
	if ((_ekf.fault_status().value == 0)
	    && (bias_variance.max() < max_var_allowed) && (bias_variance.max() < max_var_ratio * bias_variance.min())
	   ) {

		if (_gyro_cal.last_us != 0) {
			_gyro_cal.total_time_us += timestamp - _gyro_cal.last_us;

			// consider bias estimates stable when we have accumulated sufficient time
			if (_gyro_cal.total_time_us > 30_s) {
				_gyro_cal.cal_available = true;
			}
		}

		_gyro_cal.last_us = timestamp;

	} else {
		// conditions are NOT OK for learning bias, reset
		_gyro_cal = {};
	}
}

void EKF2::UpdateMagCalibration(const hrt_abstime &timestamp)
{
	// Check if conditions are OK for learning of magnetometer bias values
	// the EKF is operating in the correct mode and there are no filter faults

	static constexpr float max_var_allowed = 1e-3f;
	static constexpr float max_var_ratio = 1e2f;

	const Vector3f bias_variance{_ekf.getMagBiasVariance()};

	bool valid = _ekf.control_status_flags().in_air
		     && (_ekf.fault_status().value == 0)
		     && (bias_variance.max() < max_var_allowed)
		     && (bias_variance.max() < max_var_ratio * bias_variance.min());

	if (valid && _ekf.control_status_flags().mag_3D) {

		if (_mag_cal.last_us != 0) {
			_mag_cal.total_time_us += timestamp - _mag_cal.last_us;

			// consider bias estimates stable when we have accumulated sufficient time
			if (_mag_cal.total_time_us > 30_s) {
				_mag_cal.cal_available = true;
			}
		}

		_mag_cal.last_us = timestamp;

	} else {
		// conditions are NOT OK for learning magnetometer bias, reset timestamp
		// but keep the accumulated calibration time
		_mag_cal.last_us = 0;

		if (!valid) {
			// if a filter fault has occurred, assume previous learning was invalid and do not
			// count it towards total learning time.
			_mag_cal.total_time_us = 0;
		}
	}

	// update stored declination value
	if (!_mag_decl_saved) {
		float declination_deg;

		if (_ekf.get_mag_decl_deg(&declination_deg)) {
			_param_ekf2_mag_decl.update();

			if (PX4_ISFINITE(declination_deg) && (fabsf(declination_deg - _param_ekf2_mag_decl.get()) > 0.1f)) {
				_param_ekf2_mag_decl.set(declination_deg);
				_param_ekf2_mag_decl.commit_no_notification();
			}

			_mag_decl_saved = true;
		}
	}
}

int EKF2::custom_command(int argc, char *argv[])
{
	return print_usage("unknown command");
}

int EKF2::task_spawn(int argc, char *argv[])
{
	bool success = false;
	bool replay_mode = false;

	if (argc > 1 && !strcmp(argv[1], "-r")) {
		PX4_INFO("replay mode enabled");
		replay_mode = true;
	}

#if !defined(CONSTRAINED_FLASH)
	bool multi_mode = false;
	int32_t imu_instances = 0;
	int32_t mag_instances = 0;

	int32_t sens_imu_mode = 1;
	param_get(param_find("SENS_IMU_MODE"), &sens_imu_mode);

	if (sens_imu_mode == 0) {
		// ekf selector requires SENS_IMU_MODE = 0
		multi_mode = true;

		// IMUs (1 - 4 supported)
		param_get(param_find("EKF2_MULTI_IMU"), &imu_instances);

		if (imu_instances < 1 || imu_instances > 4) {
			const int32_t imu_instances_limited = math::constrain(imu_instances, static_cast<int32_t>(1), static_cast<int32_t>(4));
			PX4_WARN("EKF2_MULTI_IMU limited %" PRId32 " -> %" PRId32, imu_instances, imu_instances_limited);
			param_set_no_notification(param_find("EKF2_MULTI_IMU"), &imu_instances_limited);
			imu_instances = imu_instances_limited;
		}

		int32_t sens_mag_mode = 1;
		const param_t param_sens_mag_mode = param_find("SENS_MAG_MODE");
		param_get(param_sens_mag_mode, &sens_mag_mode);

		if (sens_mag_mode == 0) {
			const param_t param_ekf2_mult_mag = param_find("EKF2_MULTI_MAG");
			param_get(param_ekf2_mult_mag, &mag_instances);

			// Mags (1 - 4 supported)
			if (mag_instances > 4) {
				const int32_t mag_instances_limited = math::constrain(mag_instances, static_cast<int32_t>(1), static_cast<int32_t>(4));
				PX4_WARN("EKF2_MULTI_MAG limited %" PRId32 " -> %" PRId32, mag_instances, mag_instances_limited);
				param_set_no_notification(param_ekf2_mult_mag, &mag_instances_limited);
				mag_instances = mag_instances_limited;

			} else if (mag_instances <= 1) {
				// properly disable multi-magnetometer at sensors hub level
				PX4_WARN("EKF2_MULTI_MAG disabled, resetting SENS_MAG_MODE");

				// re-enable at sensors level
				sens_mag_mode = 1;
				param_set(param_sens_mag_mode, &sens_mag_mode);

				mag_instances = 1;
			}

		} else {
			mag_instances = 1;
		}
	}

	if (multi_mode && !replay_mode) {
		// Start EKF2Selector if it's not already running
		if (_ekf2_selector.load() == nullptr) {
			EKF2Selector *inst = new EKF2Selector();

			if (inst) {
				_ekf2_selector.store(inst);

			} else {
				PX4_ERR("Failed to create EKF2 selector");
				return PX4_ERROR;
			}
		}

		const hrt_abstime time_started = hrt_absolute_time();
		const int multi_instances = math::min(imu_instances * mag_instances, static_cast<int32_t>(EKF2_MAX_INSTANCES));
		int multi_instances_allocated = 0;

		// allocate EKF2 instances until all found or arming
		uORB::SubscriptionData<vehicle_status_s> vehicle_status_sub{ORB_ID(vehicle_status)};

		bool ekf2_instance_created[MAX_NUM_IMUS][MAX_NUM_MAGS] {}; // IMUs * mags

		while ((multi_instances_allocated < multi_instances)
		       && (vehicle_status_sub.get().arming_state != vehicle_status_s::ARMING_STATE_ARMED)
		       && ((hrt_elapsed_time(&time_started) < 30_s)
			   || (vehicle_status_sub.get().hil_state == vehicle_status_s::HIL_STATE_ON))) {

			vehicle_status_sub.update();

			for (uint8_t mag = 0; mag < mag_instances; mag++) {
				uORB::SubscriptionData<vehicle_magnetometer_s> vehicle_mag_sub{ORB_ID(vehicle_magnetometer), mag};

				for (uint8_t imu = 0; imu < imu_instances; imu++) {

					uORB::SubscriptionData<vehicle_imu_s> vehicle_imu_sub{ORB_ID(vehicle_imu), imu};
					vehicle_mag_sub.update();

					// Mag & IMU data must be valid, first mag can be ignored initially
					if ((vehicle_mag_sub.advertised() || mag == 0) && (vehicle_imu_sub.advertised())) {

						if (!ekf2_instance_created[imu][mag]) {
							EKF2 *ekf2_inst = new EKF2(true, px4::ins_instance_to_wq(imu), false);

							if (ekf2_inst && ekf2_inst->multi_init(imu, mag)) {
								int actual_instance = ekf2_inst->instance(); // match uORB instance numbering

								if ((actual_instance >= 0) && (_objects[actual_instance].load() == nullptr)) {
									_objects[actual_instance].store(ekf2_inst);
									success = true;
									multi_instances_allocated++;
									ekf2_instance_created[imu][mag] = true;

									PX4_DEBUG("starting instance %d, IMU:%" PRIu8 " (%" PRIu32 "), MAG:%" PRIu8 " (%" PRIu32 ")", actual_instance,
										  imu, vehicle_imu_sub.get().accel_device_id,
										  mag, vehicle_mag_sub.get().device_id);

									_ekf2_selector.load()->ScheduleNow();

								} else {
									PX4_ERR("instance numbering problem instance: %d", actual_instance);
									delete ekf2_inst;
									break;
								}

							} else {
								PX4_ERR("alloc and init failed imu: %" PRIu8 " mag:%" PRIu8, imu, mag);
								px4_usleep(100000);
								break;
							}
						}

					} else {
						px4_usleep(1000); // give the sensors extra time to start
						break;
					}
				}
			}

			if (multi_instances_allocated < multi_instances) {
				px4_usleep(10000);
			}
		}

	} else

#endif // !CONSTRAINED_FLASH

	{
		// otherwise launch regular
		EKF2 *ekf2_inst = new EKF2(false, px4::wq_configurations::INS0, replay_mode);

		if (ekf2_inst) {
			_objects[0].store(ekf2_inst);
			ekf2_inst->ScheduleNow();
			success = true;
		}
	}

	return success ? PX4_OK : PX4_ERROR;
}

int EKF2::print_usage(const char *reason)
{
	if (reason) {
		PX4_WARN("%s\n", reason);
	}

	PRINT_MODULE_DESCRIPTION(
		R"DESCR_STR(
### Description
Attitude and position estimator using an Extended Kalman Filter. It is used for Multirotors and Fixed-Wing.

The documentation can be found on the [ECL/EKF Overview & Tuning](https://docs.px4.io/main/en/advanced_config/tuning_the_ecl_ekf.html) page.

ekf2 can be started in replay mode (`-r`): in this mode, it does not access the system time, but only uses the
timestamps from the sensor topics.

)DESCR_STR");

	PRINT_MODULE_USAGE_NAME("ekf2", "estimator");
	PRINT_MODULE_USAGE_COMMAND("start");
	PRINT_MODULE_USAGE_PARAM_FLAG('r', "Enable replay mode", true);
	PRINT_MODULE_USAGE_DEFAULT_COMMANDS();
#if !defined(CONSTRAINED_FLASH)
	PRINT_MODULE_USAGE_COMMAND_DESCR("select_instance", "Request switch to new estimator instance");
	PRINT_MODULE_USAGE_ARG("<instance>", "Specify desired estimator instance", false);
#endif // !CONSTRAINED_FLASH
	return 0;
}

extern "C" __EXPORT int ekf2_main(int argc, char *argv[])
{
	if (argc <= 1 || strcmp(argv[1], "-h") == 0) {
		return EKF2::print_usage();
	}

	if (strcmp(argv[1], "start") == 0) {
		int ret = 0;
		EKF2::lock_module();

		ret = EKF2::task_spawn(argc - 1, argv + 1);

		if (ret < 0) {
			PX4_ERR("start failed (%i)", ret);
		}

		EKF2::unlock_module();
		return ret;

#if !defined(CONSTRAINED_FLASH)
	} else if (strcmp(argv[1], "select_instance") == 0) {

		if (EKF2::trylock_module()) {
			if (_ekf2_selector.load()) {
				if (argc > 2) {
					int instance = atoi(argv[2]);
					_ekf2_selector.load()->RequestInstance(instance);
				} else {
					EKF2::unlock_module();
					return EKF2::print_usage("instance required");
				}

			} else {
				PX4_ERR("multi-EKF not active, unable to select instance");
			}

			EKF2::unlock_module();

		} else {
			PX4_WARN("module locked, try again later");
		}

		return 0;
#endif // !CONSTRAINED_FLASH
	} else if (strcmp(argv[1], "status") == 0) {
		if (EKF2::trylock_module()) {
#if !defined(CONSTRAINED_FLASH)
			if (_ekf2_selector.load()) {
				_ekf2_selector.load()->PrintStatus();
			}
#endif // !CONSTRAINED_FLASH

			for (int i = 0; i < EKF2_MAX_INSTANCES; i++) {
				if (_objects[i].load()) {
					PX4_INFO_RAW("\n");
					_objects[i].load()->print_status();
				}
			}

			EKF2::unlock_module();

		} else {
			PX4_WARN("module locked, try again later");
		}

		return 0;

	} else if (strcmp(argv[1], "stop") == 0) {
		EKF2::lock_module();

		if (argc > 2) {
			int instance = atoi(argv[2]);

			if (instance >= 0 && instance < EKF2_MAX_INSTANCES) {
				PX4_INFO("stopping instance %d", instance);
				EKF2 *inst = _objects[instance].load();

				if (inst) {
					inst->request_stop();
					px4_usleep(20000); // 20 ms
					delete inst;
					_objects[instance].store(nullptr);
				}
			} else {
				PX4_ERR("invalid instance %d", instance);
			}

		} else {
			// otherwise stop everything
			bool was_running = false;

#if !defined(CONSTRAINED_FLASH)
			if (_ekf2_selector.load()) {
				PX4_INFO("stopping ekf2 selector");
				_ekf2_selector.load()->Stop();
				delete _ekf2_selector.load();
				_ekf2_selector.store(nullptr);
				was_running = true;
			}
#endif // !CONSTRAINED_FLASH

			for (int i = 0; i < EKF2_MAX_INSTANCES; i++) {
				EKF2 *inst = _objects[i].load();

				if (inst) {
					PX4_INFO("stopping ekf2 instance %d", i);
					was_running = true;
					inst->request_stop();
					px4_usleep(20000); // 20 ms
					delete inst;
					_objects[i].store(nullptr);
				}
			}

			if (!was_running) {
				PX4_WARN("not running");
			}
		}

		EKF2::unlock_module();
		return PX4_OK;
	}

	EKF2::lock_module(); // Lock here, as the method could access _object.
	int ret = EKF2::custom_command(argc - 1, argv + 1);
	EKF2::unlock_module();

	return ret;
}