EarthObserver

class ssapy.orbit.EarthObserver(lon, lat, elevation=0, fast=False)[source][source]

Bases: object

An earth-bound observer.

Parameters:

lon (float) – Geodetic longitude in degrees (increasing to the East).
lat (float) – Geodetic latitude in degrees.
elevation (float, optional) – Elevation in meters.
fast (bool, optional) – Use fast lookup tables for Earth Orientation parameters. ~ meter and ~10 micron/sec accurate for dates between approximately 1973 and the present. Less accurate outside this range.

lon[source]

lat[source]

elevation[source]

itrs[source]

ITRS coordinates in meters.

Type:: array_like (3,)

getRV(time)[source][source]: Get position and velocity at specified time(s) in the GCRF frame.

Methods Summary

`getRV`(time)	Get position and velocity at specified time(s).
`sunAlt`(time)	Get Sun altitude for observer at time.

Methods Documentation

getRV(time)[source][source]

Get position and velocity at specified time(s).

Parameters:

time (array_like or astropy.time.Time (n,)) – If float (array), then should correspond to GPS seconds; i.e., seconds since 1980-01-06 00:00:00 UTC

Returns:

r (array_like (n, 3)) – Position in meters.
v (array_like (n, 3)) – Velocity in meters per second.

Notes

The returned position and velocity are in the GCRF frame.

sunAlt(time)[source][source]

Get Sun altitude for observer at time.

Parameters:: time (array_like or astropy.time.Time (n,)) – If float (array), then should correspond to GPS seconds; i.e., seconds since 1980-01-06 00:00:00 UTC
Returns:: alt – Altitude of sun in radians.
Return type:: array_like(n,)