Move GPS blending from ekf2 to sensors module

- new sensors work item that subscribes to N x sensor_gps and publishes vehicle_gps_position
 - blending is now configurable with SENS_GPS_MASK and SENS_GPS_TAU

Co-authored-by: Jacob Crabill <jacob@volans-i.com>
Co-authored-by: Jacob Dahl <dahl.jakejacob@gmail.com>

msg/CMakeLists.txt

@@ -57,7 +57,6 @@ set(msg_files
 	distance_sensor.msg
 	ekf2_timestamps.msg
 	ekf_gps_drift.msg
-	ekf_gps_position.msg
 	esc_report.msg
 	esc_status.msg
 	estimator_innovations.msg
@@ -118,6 +117,7 @@ set(msg_files
 	sensor_baro.msg
 	sensor_combined.msg
 	sensor_correction.msg
+	sensor_gps.msg
 	sensor_gyro.msg
 	sensor_gyro_fifo.msg
 	sensor_mag.msg

msg/sensor_gps.msg

@@ -1,19 +1,36 @@
-# EKF blended position in WGS84 coordinates.
+# GPS position in WGS84 coordinates.
+# the field 'timestamp' is for the position & velocity (microseconds)
 uint64 timestamp		# time since system start (microseconds)
+
 int32 lat			# Latitude in 1E-7 degrees
 int32 lon			# Longitude in 1E-7 degrees
 int32 alt			# Altitude in 1E-3 meters above MSL, (millimetres)
 int32 alt_ellipsoid 		# Altitude in 1E-3 meters bove Ellipsoid, (millimetres)
+
 float32 s_variance_m_s		# GPS speed accuracy estimate, (metres/sec)
+float32 c_variance_rad		# GPS course accuracy estimate, (radians)
 uint8 fix_type # 0-1: no fix, 2: 2D fix, 3: 3D fix, 4: RTCM code differential, 5: Real-Time Kinematic, float, 6: Real-Time Kinematic, fixed, 8: Extrapolated. Some applications will not use the value of this field unless it is at least two, so always correctly fill in the fix.
+
 float32 eph			# GPS horizontal position accuracy (metres)
 float32 epv			# GPS vertical position accuracy (metres)
+
+float32 hdop			# Horizontal dilution of precision
+float32 vdop			# Vertical dilution of precision
+
+int32 noise_per_ms		# GPS noise per millisecond
+int32 jamming_indicator		# indicates jamming is occurring
+
 float32 vel_m_s			# GPS ground speed, (metres/sec)
 float32 vel_n_m_s		# GPS North velocity, (metres/sec)
 float32 vel_e_m_s		# GPS East velocity, (metres/sec)
 float32 vel_d_m_s		# GPS Down velocity, (metres/sec)
+float32 cog_rad			# Course over ground (NOT heading, but direction of movement), -PI..PI, (radians)
 bool vel_ned_valid		# True if NED velocity is valid
+
+int32 timestamp_time_relative	# timestamp + timestamp_time_relative = Time of the UTC timestamp since system start, (microseconds)
+uint64 time_utc_usec		# Timestamp (microseconds, UTC), this is the timestamp which comes from the gps module. It might be unavailable right after cold start, indicated by a value of 0
+
 uint8 satellites_used		# Number of satellites used
+
 float32 heading			# heading angle of XYZ body frame rel to NED. Set to NaN if not available and updated (used for dual antenna GPS), (rad, [-PI, PI])
 float32 heading_offset		# heading offset of dual antenna array in body frame. Set to NaN if not applicable. (rad, [-PI, PI])
-uint8 selected			# GPS selection: 0: GPS1, 1: GPS2. 2: GPS1+GPS2 blend

msg/tools/uorb_rtps_message_ids.yaml

@@ -43,7 +43,7 @@ rtps:
     id: 19
   - msg: ekf_gps_drift
     id: 20
-  - msg: ekf_gps_position
+  - msg: sensor_gps
     id: 21
   - msg: esc_report
     id: 22

msg/vehicle_gps_position.msg

@@ -34,3 +34,5 @@ uint8 satellites_used		# Number of satellites used
 
 float32 heading			# heading angle of XYZ body frame rel to NED. Set to NaN if not available and updated (used for dual antenna GPS), (rad, [-PI, PI])
 float32 heading_offset		# heading offset of dual antenna array in body frame. Set to NaN if not applicable. (rad, [-PI, PI])
+
+uint8 selected			# GPS selection: 0: GPS1, 1: GPS2. 2: GPS3. 3. Blending multiple receivers