Calibration Target Data Input File#

In order to perform a Point Target Data analysis using this tool, both from the CLI interface or by using the exposed python function interfaces, an external Point Target Data file containing calibration target locations and other useful information must be provided.

To properly orchestrate the whole analysis, a fixed file structure with predefined column names has been choose as a standard for this application. The template of this .csv file can be downloaded from the GitHub sct/resources folder and filled by the user with the information needed.

Here is a description of the columns of this file and an example of point target input file.

target_name: name of the target, i.e. “CR_1” (do not use spaces)
target_type: type of target, it can be a corner reflector “CR” or an active transponder “TX”
plate: tectonic plate of reference, information used to compute tectonic displacement if needed
description: string description of the target, if needed
latitude_deg: point target location, latitude coordinate in degrees
longitude_deg: point target location, longitude coordinate in degrees
altitude_m: point target location, height in meters
x_coord_m, y_coord_m, z_coord_m: point target location, XYZ coordinates in meters (ECEF system)
drift_velocity_x_my, drift_velocity_y_my, drift_velocity_z_my: point target measured drift velocities components in meters per year these data are used to compute the calibration target displacement with a more accurate estimate
corner_azimuth_deg, corner_elevation_deg: corner reflector orientation parameters needed for proper RCS computation
target_shape, target_size_m: corner reflector shape and size needed for proper RCS computation
rcs_hh_dB, rcs_hv_dB, rcs_vv_dB, rcs_vh_dB: corner reflector RCS magnitude in dB, used to computed RCS error
delay_s: active calibration target response delay in seconds
measurement_date: date of measurement of the input data, as an UTC string
validity_start_date: start date of validity for the given data
validity_stop_date: end date of validity for the given data

Data validation, enums and conventions#

Calibration target data are validated inside the program and several of these columns are needed to perform specific actions and computations that are optional and can be enable/disabled from the configuration file.

In particular, the following information is mandatory because it corresponds to the bare minimum required to perform the analysis:

target_name, target_type, latitude_deg, longitude_deg, altitude_m, x_coord_m, y_coord_m, z_coord_m

Additional information such as plate and drift_velocity_x_my, drift_velocity_y_my, drift_velocity_z_my can be specified to compute the plate tectonics corrections using the internally defined drift model (just the plate column is needed in this case) or by using the user defined drift velocities fro a more accurate estimate.

Important

The plate value maps to an internal enum class providing a list to the available plates supported by the default plate tectonics drift model implemented following the ITRF2014-PMM. Plate names are those defined in this paper.

In these cases, if the plate drift is to be evaluated, measurement_date, validity_start_date and validity_stop_date must be populated with UTC dates in order to compute the time interval between the registering of the coordinates provided and the actual sensor acquisition date.

Dataset Example#

target_name	target_type	plate	description	latitude_deg	longitude_deg	altitude_m	x_coord_m	y_coord_m	z_coord_m	drift_velocity_x_my	drift_velocity_y_my	drift_velocity_z_my	corner_azimuth_deg	corner_elevation_deg	target_shape	target_size_m	measurement_date	validity_start_date	validity_stop_date
CR_1	CR	AUST	Surat Basin	-26.8347098	151.1656039	409.4544	-4989394.0436	2746844.3890	-2862070.0899	-0.0325	-0.0083	0.0487	257.10	53.32	trihedral	1.5	2020-01-01 00:00:00.000	2020-01-01 00:00:00.000	2099-01-01 00:00:00.000
CR_2	CR	AUST	Surat Basin	-26.9516331	151.2376126	432.7094	-4987723.0920	2737761.6619	-2873635.5867	-0.0325	-0.0082	0.0486	256.21	53.33	trihedral	1.5	2020-01-01 00:00:00.000	2020-01-01 00:00:00.000	2099-01-01 00:00:00.000
CR_3	CR	AUST	Surat Basin	-27.1007318	151.2588089	391.8599	-4982121.1136	2732288.8068	-2888334.6208	-0.0326	-0.0081	0.0485	258.46	54.34	trihedral	1.5	2020-01-01 00:00:00.000	2020-01-01 00:00:00.000	2099-01-01 00:00:00.000
CR_4	CR	AUST	Surat Basin	-27.3088713	151.2719591	385.2420	-4973496.3076	2726074.1767	-2908844.8033	-0.0326	-0.0079	0.0484	258.51	54.67	trihedral	1.5	2020-01-01 00:00:00.000	2020-01-01 00:00:00.000	2099-01-01 00:00:00.000