Rename distance_sensor.covariance to variance

src/modules/local_position_estimator/sensors/lidar.cpp

@@ -77,7 +77,7 @@ void BlockLocalPositionEstimator::lidarCorrect()
 	// use parameter covariance unless sensor provides reasonable value
 	SquareMatrix<float, n_y_lidar> R;
 	R.setZero();
-	float cov = _sub_lidar->get().covariance;
+	float cov = _sub_lidar->get().variance;
 
 	if (cov < 1.0e-3f) {
 		R(0, 0) = _lidar_z_stddev.get() * _lidar_z_stddev.get();

src/modules/local_position_estimator/sensors/sonar.cpp

@@ -86,7 +86,7 @@ void BlockLocalPositionEstimator::sonarCorrect()
 	    && !(_sensorTimeout & SENSOR_LIDAR)) { return; }
 
 	// calculate covariance
-	float cov = _sub_sonar->get().covariance;
+	float cov = _sub_sonar->get().variance;
 
 	if (cov < 1.0e-3f) {
 		// use sensor value if reasoanble