poliastro.earth.util

Module Contents

Functions

raan_from_ltan(epoch[, ltan])	RAAN angle from LTAN for SSO around the earth.
get_local_sidereal_time(lon, time)	Gets the local sideral time from input location.

poliastro.earth.util.raan_from_ltan(epoch, ltan=12.0)

RAAN angle from LTAN for SSO around the earth.

Parameters

• epoch (Time) – Value of time to calculate the RAAN for

• ltan (Quantity) – Decimal hour between 0 and 24

Returns

RAAN – Right ascension of the ascending node angle in GCRS

Return type

Quantity

Notes

Calculations of the sun mean longitude and equation of time follow “Fundamentals of Astrodynamics and Applications” Fourth edition by Vallado, David A.

poliastro.earth.util.get_local_sidereal_time(lon, time)

Gets the local sideral time from input location.

Parameters

• lon (astropy.units.Quantity) – East longitude of a point on a body.

• time (astropy.time.Time) – Time at which to calculate the local sidereal time.

Returns

theta – Local Sidereal Time (LST).

Return type

astropy.units.Quantity