satkit.utils.utilities

Utility functions.

Functions

`compute_gnd_az_el`(t, gnd_pos, pvt, frame[, ...])	Computes the azimuth, elevation, range and range rate for a given position (e.g., of a satellite) and a ground location.
`compute_gnd_az_el_list`(interval, gnd_pos, ...)	Computes the azimuth-elevation-range list within an interval, for an object flying over a ground location.
`init_topo_frame`(gnd_pos[, planet])	Initialises the Topocentric Frame.

Classes

AzElRng(t, az, el, rng, rng_rate)

Create new instance of AzElRng(t, az, el, rng, rng_rate)

class AzElRng(t, az, el, rng, rng_rate)

Create new instance of AzElRng(t, az, el, rng, rng_rate)

az: Alias for field number 1

el: Alias for field number 2

rng: Alias for field number 3

rng_rate: Alias for field number 4

t: Alias for field number 0

compute_gnd_az_el(t, gnd_pos, pvt, frame, planet=None, refraction_model=None)[source]

Computes the azimuth, elevation, range and range rate for a given position (e.g., of a satellite) and a ground location.

This method is not limited to a ground location on Earth (as defined by the planet parameter).

Atmospheric Refraction Model should be set to None for communications applications. It can be set to EarthITU453AtmosphereRefraction or EarthStandardAtmosphereRefraction (provided by Orekit) for visual or optical applications.

Return type

AzElRng

Parameters

t (AbsoluteDate) – Time for computation
gnd_pos (org.orekit.bodies.GeodeticPoint | org.orekit.frames.TopocentricFrame) – Ground position in geodetic coordinates (or the topocentric frame associated with it)
pvt (TimeStampedPVCoordinates) – Coordinates of the object (e.g., satellite)
frame (Frame) – Frame associated with the coordinates of the object
planet (OneAxisEllipsoid) – The planet where the ground location is located. Defaults to WGS84 Earth.
refraction_model (AtmosphericRefractionModel) – Atmospheric Refraction Model, defaults to None

Returns

Azimuth-Elevation-Range named tuple

Return type

AzElRng

compute_gnd_az_el_list(interval, gnd_pos, propagator, planet=None, refraction_model=None, az_el_timestep=<Quantity(60, 'second')>)[source]

Computes the azimuth-elevation-range list within an interval, for an object flying over a ground location.

This method is not limited to a ground location on Earth (as defined by the planet parameter).

The planet parameter can be any OneAxisEllipsoid with its own fixed frame. For example, Earth can be generated as follows:

itrf = FramesFactory.getITRF(IERSConventions.IERS_2010, True)
earth = OneAxisEllipsoid(Constants.WGS84_EARTH_EQUATORIAL_RADIUS,
                         Constants.WGS84_EARTH_FLATTENING,
                         itrf)

If the gnd_pos parameter is defined as a TopocentricFrame, then the optional planet parameter is ignored. Otherwise, it is set to Earth as given above.

Atmospheric Refraction Model should be set to None for communications applications. It can be set to EarthITU453AtmosphereRefraction or EarthStandardAtmosphereRefraction (provided by Orekit) for visual or optical applications.

Return type

list[AzElRng]

Parameters

interval (TimeInterval) – Computation interval for the az-el-rng values
gnd_pos (org.orekit.bodies.GeodeticPoint | org.orekit.frames.TopocentricFrame) – Ground position in geodetic coordinates (or the topocentric frame associated with it)
propagator (Propagator) – Propagator to generate the trajectory of the satellite (or any other object)
planet (OneAxisEllipsoid) – The planet where the ground location is located. Defaults to WGS84 Earth.
refraction_model (AtmosphericRefractionModel) – Atmospheric Refraction Model, defaults to None
az_el_timestep – Stepsize for the azimuth-elevation-range list

Returns

List of azimuth-Elevation-Range named tuples

Return type

list[AzElRng]

init_topo_frame(gnd_pos, planet=None)[source]

Initialises the Topocentric Frame.

Return type

TopocentricFrame

Parameters

gnd_pos (org.orekit.bodies.GeodeticPoint | org.orekit.frames.TopocentricFrame) – Ground position in geodetic coordinates (or the topocentric frame associated with it)
planet (OneAxisEllipsoid) – The planet where the ground position is located. Defaults to WGS84 Earth.

Returns

Topocentric frame belonging to the Ground Position

Return type

TopocentricFrame