Merge pull request #599 from ut-issl/feature/refactor-gnss-receiver

Refactor GNSS receiver

data/sample/initialize_files/components/gnss_receiver.ini

@@ -6,37 +6,32 @@ antenna_position_b_m(0) = 0.0125
 antenna_position_b_m(1) = 0.0000
 antenna_position_b_m(2) = 0.1815
 
-// Quaternion from body frame to component frame
+// Quaternion from body frame to component frame of the antenna
+// Note: The antenna boresight direction is +Z direction at the component frame
 quaternion_b2c(0) = 0.0
 quaternion_b2c(1) = 0.0
 quaternion_b2c(2) = 0.0
 quaternion_b2c(3) = 1.0
 
 // Antenna model
-// 0... simple model : GNSS sats are visible when antenna directs anti-earth direction
-// 1... cone model : GNSS sats visible when a sat is in a cone
-antenna_model = 0
+// SIMPLE: We assume that GNSS satellites are visible when antenna directs anti-earth direction
+// CONE: We calculate the number of GNSS satellites in the antenna,
+// and the position is observable when more than 4 satellites are in the antenna.
+// Note : We need to enable the GNSS satellite calculation when we use this mode.
+// All satellites managed in the GnssSatellite class are used in this model.
+antenna_model = SIMPLE
 
 // Antenna half width [deg]
 antenna_half_width_deg = 60
 
-// Number of channels
-maximum_channel = 8
+// Random noise for simple position observation
+white_noise_standard_deviation_position_ecef_m(0) = 2000.0
+white_noise_standard_deviation_position_ecef_m(1) = 1000.0
+white_noise_standard_deviation_position_ecef_m(2) = 1500.0
 
-// GNSS ID 
-// G...GPS
-// R...GLONASS
-// E...Galileo
-// C...Beidou
-// J...QZSS
-// if your receiver is compatible with all kind of gnss satellites : GRECJ
-// if your receiver is compatible with GPS and QZSS : GJ
-gnss_id = G
-
-//Random noise [m]
-white_noise_standard_deviation_eci_m(0) = 10000.0
-white_noise_standard_deviation_eci_m(1) = 1000.0
-white_noise_standard_deviation_eci_m(2) = 1000.0
+white_noise_standard_deviation_velocity_ecef_m_s(0) = 1.0
+white_noise_standard_deviation_velocity_ecef_m_s(1) = 1.5
+white_noise_standard_deviation_velocity_ecef_m_s(2) = 2.0
 
 [POWER_PORT]
 minimum_voltage_V = 3.3

scripts/Plot/plot_gnss_receiver.py

@@ -49,14 +49,14 @@
 # Read S2E CSV
 time = read_scalar_from_csv(read_file_name, 'elapsed_time[s]')
 
-measured_position_eci_m = read_3d_vector_from_csv(read_file_name, 'gnss_receiver1_measured_position_eci', 'm')
-true_position_eci_m = read_3d_vector_from_csv(read_file_name, 'spacecraft_position_i', 'm')
+measured_position_ecef_m = read_3d_vector_from_csv(read_file_name, 'gnss_receiver1_measured_position_ecef', 'm')
+true_position_ecef_m = read_3d_vector_from_csv(read_file_name, 'spacecraft_position_ecef', 'm')
 
 number_of_visible_satellites = read_scalar_from_csv(read_file_name, 'gnss_receiver1_number_of_visible_satellites')
 satellite_visible_flag = read_scalar_from_csv(read_file_name, 'gnss_receiver1_satellite_visible_flag')
 
 # Statistics
-error_m = measured_position_eci_m[:, 1:] - true_position_eci_m[:, 1:]
+error_m = measured_position_ecef_m[:, 1:] - true_position_ecef_m[:, 1:]
 average = [0.0, 0.0, 0.0]
 standard_deviation = [0.0, 0.0, 0.0]
 for i in range(3):
@@ -68,20 +68,20 @@
 #
 unit = ' m'
 fig, axis = plt.subplots(5, 1, squeeze = False, tight_layout = True, sharex = True)
-axis[0, 0].plot(time[0], measured_position_eci_m[0], marker=".", c="red", label="MEASURED-X")
-axis[0, 0].plot(time[0], true_position_eci_m[0], marker=".", c="orange", label="TRUE-X")
+axis[0, 0].plot(time[0], measured_position_ecef_m[0], marker=".", c="red", label="MEASURED-X")
+axis[0, 0].plot(time[0], true_position_ecef_m[0], marker=".", c="orange", label="TRUE-X")
 axis[0, 0].text(0.01, 0.99, "Error average:" + format(average[0], '+.2e') + unit, verticalalignment = 'top', transform = axis[0, 0].transAxes)
 axis[0, 0].text(0.01, 0.79, "Standard deviation:" + format(standard_deviation[0], '+.2e') + unit, verticalalignment = 'top', transform = axis[0, 0].transAxes)
 axis[0, 0].legend(loc = 'upper right')
 
-axis[1, 0].plot(time[0], measured_position_eci_m[1], marker=".", c="green", label="MEASURED-Y")
-axis[1, 0].plot(time[0], true_position_eci_m[1], marker=".", c="yellow", label="TRUE-Y")
+axis[1, 0].plot(time[0], measured_position_ecef_m[1], marker=".", c="green", label="MEASURED-Y")
+axis[1, 0].plot(time[0], true_position_ecef_m[1], marker=".", c="yellow", label="TRUE-Y")
 axis[1, 0].text(0.01, 0.99, "Error average:" + format(average[1], '+.2e') + unit, verticalalignment = 'top', transform = axis[1, 0].transAxes)
 axis[1, 0].text(0.01, 0.79, "Standard deviation:" + format(standard_deviation[1], '+.2e') + unit, verticalalignment = 'top', transform = axis[1, 0].transAxes)
 axis[1, 0].legend(loc = 'upper right')
 
-axis[2, 0].plot(time[0], measured_position_eci_m[2], marker=".", c="blue", label="MEASURED-Z")
-axis[2, 0].plot(time[0], true_position_eci_m[2], marker=".", c="purple", label="TRUE-Z")
+axis[2, 0].plot(time[0], measured_position_ecef_m[2], marker=".", c="blue", label="MEASURED-Z")
+axis[2, 0].plot(time[0], true_position_ecef_m[2], marker=".", c="purple", label="TRUE-Z")
 axis[2, 0].text(0.01, 0.99, "Error average:" + format(average[2], '+.2e') + unit, verticalalignment = 'top', transform = axis[2, 0].transAxes)
 axis[2, 0].text(0.01, 0.79, "Standard deviation:" + format(standard_deviation[2], '+.2e') + unit, verticalalignment = 'top', transform = axis[2, 0].transAxes)
 axis[2, 0].legend(loc = 'upper right')
@@ -94,7 +94,7 @@
 axis[4, 0].legend(loc = 'upper right')
 axis[4, 0].set_ylim(0, max(number_of_visible_satellites[0]) + 2)
 
-fig.suptitle("GNSS Receiver Spacecraft position @ ECI")
+fig.suptitle("GNSS Receiver Spacecraft position @ ECEF")
 fig.supylabel("Position [m]")
 fig.supxlabel("Time [s]")