gcp::util::Astrometry Class Reference

Classes
struct	Date

Public Member Functions
	Astrometry ()
virtual	~Astrometry ()
void	extendUt1Utc (double mjd, double ut1utc)
void	extendEqnEqx (double tt, double eqneqx)
double	getUt1Utc (double mjd)
double	getEqnEqx (double tt)
bool	canBracket (double mjdUtc)
HourAngle	mjdUtcToLst (double mjdUtc, Angle longitude)

Static Public Member Functions
static HourAngle	mjdUtcToLst (double mjdUtc, Angle longitude, double ut1Utc, double eqnEqx)
static double	mjdUtcToMjdTt (double mjdUtc)
static Date	mjdUtcToCalendarDate (double mjdUtc)

Constructor & Destructor Documentation

Astrometry::Astrometry

(

)

Constructor.

....................................................................... Constructor.

Astrometry::~Astrometry ( )

virtual

Destructor.

....................................................................... Destructor.

Member Function Documentation

bool Astrometry::canBracket

(

double

mjdUtc

)

Return true if ephemeris parameters can be interpolated for this timestamp

....................................................................... Return true if ephemeris parameters can be interpolated for this timestamp

void Astrometry::extendEqnEqx	(	double	tt,
		double	eqnEqx
	)

Extend the quadratic interpolation table of the equation of the equinoxes versus Terrestrial Time (as a Modified Julian Date).

Exceptions

Exception	....................................................................... Extend the quadratic interpolation table of the equation of the equinoxes versus Terrestrial Time (as a Modified Julian Date).
Exception

void Astrometry::extendUt1Utc	(	double	mjd,
		double	ut1Utc
	)

Extend the quadratic interpolation table of ut1 - utc versus MJD UTC.

Exceptions

Exception	....................................................................... Extend the quadratic interpolation table of ut1 - utc versus MJD UTC.
Exception

double Astrometry::getEqnEqx

(

double

mjdTt

)

Get the value of the equation of the equinoxes for a given terrestrial time.

Exceptions

Exception	....................................................................... Get the value of the equation of the equinoxes for a given terrestrial time.
Exception

double Astrometry::getUt1Utc

(

double

mjdUtc

)

Get the value of UT1-UTC for a given UTC.

Exceptions

Exception	....................................................................... Get the value of UT1-UTC for a given UTC.
Exception

HourAngle Astrometry::mjdUtcToLst ( double  mjd, Angle  longitude, double  ut1Utc, double  eqnEqx  )

static

Return the local sidereal time for a given site and UTC.

Input:

utc double The current date and time (UTC), expressed as a Modified Julian Date. longitude double The longitude at which the lst is desired ut1Utc double The current value of UT1-UTC. If you don't need more than one second of accuracy, this can be given as zero.

eqnEqx double The current value of the equation of the equinoxes if you want apparent sidereal time, or 0 if you can make do with mean sidereal time. The equation of the equinoxes is a slowly varying number that is computationally intensive to calculate so it doesn't make sense to calculate it anew on each call. Output:

return double The local sidereal time, expressed in radians.

...................................................................... Return the local sidereal time for a given site and UTC.

Input: utc double The current date and time (UTC), expressed as a Modified Julian Date. longitude double The longitude at which the lst is desired ut1Utc double The current value of UT1-UTC. If you don't need more than one second of accuracy, this can be given as zero. eqnEqx double The current value of the equation of the equinoxes if you want apparent sidereal time, or 0 if you can make do with mean sidereal time. The equation of the equinoxes is a slowly varying number that is computationally intensive to calculate, so it doesn't make sense to calculate it anew on each call. Output: return double The local sidereal time, expressed in radians.

HourAngle Astrometry::mjdUtcToLst	(	double	mjdUtc,
		Angle	longitude
	)

Same as above, using internal ephemerides

....................................................................... Same as above, using internal ephemerides

double Astrometry::mjdUtcToMjdTt ( double  mjdUtc )

static

Return the Terestrial time (aka Ephemeris Time), corresponding to a given UTC (expressed as a Modified Julian date).

Input:

mjd double The Modified Julian date.

Output:

return double The corresponding Terrestrial Time

...................................................................... Return the Terestrial time (aka Ephemeris Time), corresponding to a given UTC (expressed as a Modified Julian date).

Input:

mjd double The Modified Julian date.

Output:

return double The corresponding Terrestrial Time

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The documentation for this class was generated from the following files:

• gcpCbass/util/common/Astrometry.h
• gcpCbass/util/common/Astrometry.cc