SiderealTime.cc File Reference

#include "Date.h"

Include dependency graph for SiderealTime.cc:

Functions
double	GreenwichMeanSiderealTime (const double aGps)
	Returns the Greenwich Mean Sidereal Time in RADIANS for a specified GPS time.
double	GreenwichSiderealTime (const double aGps, const double aEquationOfEquinoxes)
	Returns the Greenwich mean or aparent sideral time in radians.

Function Documentation

GreenwichMeanSiderealTime()

double GreenwichMeanSiderealTime

(

const double

aGps

)

Returns the Greenwich Mean Sidereal Time in RADIANS for a specified GPS time.

Convenience wrapper, calling GreenwichSiderealTime() with the equation of equinoxes set to 0.

Parameters

[in]

aGps

GPS time [s].

GreenwichSiderealTime()

double GreenwichSiderealTime	(	const double	aGps,
		const double	aEquationOfEquinoxes
	)

Returns the Greenwich mean or aparent sideral time in radians.

Aparent sidereal time is computed by providing the equation of equinoxes in units of seconds. For mean sidereal time, set this parameter to 0.

This function returns the sidereal time in radians measured from the Julian epoch (current J2000). The result is NOT modulo 2 pi.

Inspired by the function sidereal_time() in the NOVAS-C library, version 2.0.1, which is dated December 10th, 1999, and carries the following references:

Aoki, et al. (1982) Astronomy and Astrophysics 105, 359-361. Kaplan, G. H. "NOVAS: Naval Observatory Vector Astrometry Subroutines"; USNO internal document dated 20 Oct 1988; revised 15 Mar 1990.

See also

http://aa.usno.navy.mil/software/novas for more information.

Parameters

[in]	aGps	GPS time [s].
[in]	aEquationOfEquinoxes	Equation of equinoxes in [s]. For mean sidereal time, set this parameter to 0.