PyCoordTopocentric

class cysgp4.PyCoordTopocentric(double az_deg=0, double el_deg=0, double dist_km=0, double dist_rate_km_per_s=0)

Bases: object

Thin wrapper around sgp4 (C++) CoordTopocentric struct.

The CoordTopocentric struct holds a topocentric location (azimuth, elevation, range/distance and distance/range rate).

Note: the topocentric position of a satellite is always relative to an observer (in SGP4 the observer is defined in geographic coordinates). The distance and distance change (aka range rate) is thus the distance between the satellite and the observer. However, this struct/class only holds the azimuth, elevation, distance and distance rate parameters, but contains no information on the observer. It is only useful in conjuction with a PyObserver (which holds a reference to a geographic location) and a datetime; see Satellite.

Parameters:

az_degfloat (default: 0.)

Azimuth of topocentric location [deg].

el_degfloat (default: 0.)

Elevation of topocentric location [deg].

dist_kmfloat (default: 0.)

Distance/range of topocentric location [km].

dist_rate_km_per_sfloat (default: 0.)

Distance/range rate of topocentric location [km/s].

Returns:

topoPyCoordTopocentric object

Examples

Constructing and using a PyCoordTopocentric object is straightforward:

>>> from cysgp4 import PyCoordTopocentric

>>> az_deg, el_deg = 130.1, 10.53
>>> dist_km, dist_rate_kms = 1200., 0.03
>>> topo = PyCoordTopocentric(az_deg, el_deg, dist_km, dist_rate_kms)
>>> topo
<PyCoordTopocentric: 130.1000d, 10.5300d, 1200.0000km, 0.0300km/s>

>>> # Access is also possible via properties, e.g.:
>>> topo.az
130.1
>>> topo.dist = 1000.

Attributes Summary

az	Topocentric azimuth [deg] (see also Class documentation).
dist	Topocentric distance [km] (see also Class documentation).
dist_rate	Topocentric distance rate [km/s] (see also Class documentation).
el	Topocentric elevation [deg] (see also Class documentation).

Attributes Documentation

az

Topocentric azimuth [deg] (see also Class documentation).

dist

Topocentric distance [km] (see also Class documentation).

dist_rate

Topocentric distance rate [km/s] (see also Class documentation).

el

Topocentric elevation [deg] (see also Class documentation).