This class implements various astronomical time computation routines. More...

#include <carma/services/AstroTime.h>

Public Member Functions
	AstroTime ()
	No-arg Constructor. More...

	AstroTime (Location location)
	Constructor specifying the location for calculating the time functions. More...

double	eqnEqx (double mjd=carma::util::Time::MJD())

Location	getSite () const

double	hourAngle (double mjd, double RA)
	Compute the hour angle for a given RA and time, at the location set in setSite() More...

HourAngle	hourAngle (double mjd, Angle RA)
	Compute the hour angle for a given RA and time, at the location set in setSite() More...

double	iersTableAge ()

double	localSiderealTime (double mjd=carma::util::Time::MJD())

std::string	lstString (double mjd=carma::util::Time::MJD(), int precision=1)

double	meanSiderealTime (double mjd=carma::util::Time::MJD())

void	setSite (Angle longitude, Angle latitude, Length altitude)
	Set the location for calculating the time functions using Conformable Quantities. More...

void	setSite (double longitude, double latitude, double altitude)
	Set the location for calculating the time functions using native types. More...

void	setSite (Location location)
	Set the location for calculating the time functions. More...

double	ut1Utc (double mjd=carma::util::Time::MJD())

double	xPolar (double mjd=carma::util::Time::MJD())

double	yPolar (double mjd=carma::util::Time::MJD())

virtual	~AstroTime ()
	Destructor. More...

Static Public Member Functions
static double	elapsedJulCent (double mjd=carma::util::Time::MJD())
	Computes the time in Julian Centuries (36525 days of universal time) elapsed since 2000 January 1 12 UT. More...

static double	julianDay (double mjd=carma::util::Time::MJD())
	Returns the Julian Day given the Modified Julian Day. More...

static double	leap (const double mjd)
	retrieve the number of leap seconds to be added to UTC to get TIA More...

static double	modulo24 (double hours)

Static Public Attributes
static const double	HOURS_PER_DAY
	The number of solar hours per solar day. More...

static const double	HOURS_PER_RADIAN
	Number of solar hours per radian, i.e. More...

static const double	HOURS_PER_SIDEREAL_DAY
	The number of solar hours per sidereal day. More...

static const double	JULIAN_CENTURY
	Value of one Julian Century, in days. More...

static const double	JULIAN_DAY_ZERO
	Difference between Julian Day and Modified Julian Day. More...

static const double	MINUTES_PER_DAY
	The number of minutes per solar day. More...

static const double	MINUTES_PER_HOUR
	Number of minutes in one hour. More...

static const double	SECONDS_PER_DAY
	The number of seconds per solar day. More...

static const double	SECONDS_PER_HOUR
	Number of seconds in one hour. More...

static const double	SIDEREAL_DAY
	The length of a sidereal day in solar days. More...

static const double	SOLAR_DAY
	The length of a solar day in sidereal days. More...

Detailed Description

This class implements various astronomical time computation routines.

Definition at line 32 of file AstroTime.h.

Constructor & Destructor Documentation

carma::services::AstroTime::AstroTime ( )

No-arg Constructor.

carma::services::AstroTime::AstroTime ( Location location )

Constructor specifying the location for calculating the time functions.

Parameters

location The longitude, latitude, and altitude of the site represented by a Location object.

virtual carma::services::AstroTime::~AstroTime ( )

virtual

Destructor.

Member Function Documentation

static double carma::services::AstroTime::elapsedJulCent ( double mjd = carma::util::Time::MJD() )

static

Computes the time in Julian Centuries (36525 days of universal time) elapsed since 2000 January 1 12 UT.

This quantity is commonly called TU and
TU = ( JD - 2451545.0 )/36525.0;

Parameters

mjd	the MJD at which to compute TU. Defaults to the MJD at the time the method is called.

Returns: the Julian Century for the given Modified Julian Day

double carma::services::AstroTime::eqnEqx ( double mjd = carma::util::Time::MJD() )

Parameters

mjd	modified julian day

Returns: the equation of the equinoxes in seconds (i.e. the difference between apparent and mean sidereal times) specified by setSite and the given mjd.

Location carma::services::AstroTime::getSite ( ) const

Returns: Location containing lon, lat, alt (Angle,Angle,Length)

double carma::services::AstroTime::hourAngle	(	double	mjd,
		double	RA
	)

Compute the hour angle for a given RA and time, at the location set in setSite()

Parameters

mjd	modified julian date
RA	the right ascension, in radians

Returns: The hour angle in radians, guaranteed to be between -PI and PI

HourAngle carma::services::AstroTime::hourAngle	(	double	mjd,
		Angle	RA
	)

Compute the hour angle for a given RA and time, at the location set in setSite()

Parameters

mjd	modified julian date
RA	an Angle representing the right ascension

Returns: an HourAngle representing the hour angle

double carma::services::AstroTime::iersTableAge ( )

Returns: the age in days of the member IERS table in days

See Also: IERSTable::age()

static double carma::services::AstroTime::julianDay ( double mjd = carma::util::Time::MJD() )

static

Returns the Julian Day given the Modified Julian Day.

Parameters

mjd	the MJD at which to compute the JD. Defaults to the MJD at the time the method is called.

Returns: the Julian Day for the given MJD

static double carma::services::AstroTime::leap ( const double mjd )

static

retrieve the number of leap seconds to be added to UTC to get TIA

See Also: http://maia.usno.navy.mil/eo/leapsec.html

Parameters

mjd	modified julian date

Returns: number of leap seconds (currently about 32)

double carma::services::AstroTime::localSiderealTime ( double mjd = carma::util::Time::MJD() )

Parameters

mjd	modified julian day

Returns: the local apparent sidereal time in hours at the location specified by setSite and the given mjd.

std::string carma::services::AstroTime::lstString	(	double	mjd = `carma::util::Time::MJD()`,
		int	precision = `1`
	)

Parameters

mjd	modified julian day
precision	digits to the right of the decimal for seconds

Returns: The local sidereal time as a sexagesimal string, HH:MM:SS[.sss]

double carma::services::AstroTime::meanSiderealTime ( double mjd = carma::util::Time::MJD() )

Parameters

mjd	modified julian day specified by setSite and the given mjd.

static double carma::services::AstroTime::modulo24 ( double hours )

static

Parameters

hours Inpu time in hours the input hours modulo 24;

void carma::services::AstroTime::setSite	(	Angle	longitude,
		Angle	latitude,
		Length	altitude
	)

Set the location for calculating the time functions using Conformable Quantities.

Parameters

longitude	Angle representing the site longitude
latitude	Angle representing the site latitude
altitude	Length representing the site altitude

void carma::services::AstroTime::setSite	(	double	longitude,
		double	latitude,
		double	altitude
	)

Set the location for calculating the time functions using native types.

Parameters

longitude	the site longitude in radians
latitude	the site latitude in radians
altitude	the site altitude in meters

void carma::services::AstroTime::setSite ( Location location )

Set the location for calculating the time functions.

Parameters

location The longitude, latitude, and altitude of the site represented by a Location object.

double carma::services::AstroTime::ut1Utc ( double mjd = carma::util::Time::MJD() )

Parameters

mjd	modified julian day

Returns: the UT1 minus UTC (dut1) difference in seconds at the given mjd Based on the IERS tables

double carma::services::AstroTime::xPolar ( double mjd = carma::util::Time::MJD() )

Parameters

mjd	modified julian day

Returns: X polar motion, in arcsecs Based on the IERS tables

double carma::services::AstroTime::yPolar ( double mjd = carma::util::Time::MJD() )

Parameters

mjd	modified julian day

Returns: Y polar motion, in arcsecs Based on the IERS tables

Member Data Documentation

const double carma::services::AstroTime::HOURS_PER_DAY

static

The number of solar hours per solar day.

Definition at line 233 of file AstroTime.h.

const double carma::services::AstroTime::HOURS_PER_RADIAN

static

Number of solar hours per radian, i.e.

12/pi

Definition at line 263 of file AstroTime.h.

const double carma::services::AstroTime::HOURS_PER_SIDEREAL_DAY

static

The number of solar hours per sidereal day.

Definition at line 238 of file AstroTime.h.

const double carma::services::AstroTime::JULIAN_CENTURY

static

Value of one Julian Century, in days.

Definition at line 211 of file AstroTime.h.

const double carma::services::AstroTime::JULIAN_DAY_ZERO

static

Difference between Julian Day and Modified Julian Day.

JD = MJD + JULIAN_DAY_ZERO

Definition at line 206 of file AstroTime.h.

const double carma::services::AstroTime::MINUTES_PER_DAY

static

The number of minutes per solar day.

Definition at line 228 of file AstroTime.h.

const double carma::services::AstroTime::MINUTES_PER_HOUR

static

Number of minutes in one hour.

Definition at line 258 of file AstroTime.h.

const double carma::services::AstroTime::SECONDS_PER_DAY

static

The number of seconds per solar day.

Definition at line 216 of file AstroTime.h.

const double carma::services::AstroTime::SECONDS_PER_HOUR

static

Number of seconds in one hour.

Definition at line 253 of file AstroTime.h.

const double carma::services::AstroTime::SIDEREAL_DAY

static

The length of a sidereal day in solar days.

Definition at line 248 of file AstroTime.h.

const double carma::services::AstroTime::SOLAR_DAY

static

The length of a solar day in sidereal days.

Definition at line 243 of file AstroTime.h.

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

carma/services/AstroTime.h

Public Member Functions

Static Public Member Functions

Static Public Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation