Positional Astronomy

Utilities for calculating sky positions

Functions
template<typename realT >
int	mx::astro::calcAzEl (realT &az, realT &el, realT ha, realT dec, realT lat)
	Calculates the Azimuth and Elevation for a given Hour-Angle, Declination, and Latitude.
template<typename realT >
realT	mx::astro::parAngRad (realT sinHA, realT cosHA, realT sinDec, realT cosDec, realT tanLat)
	Calculate the Parallactic Angle from the pre-calculated trig functions. Result in radians.
template<typename realT >
realT	mx::astro::parAngDeg (realT sinHA, realT cosHA, realT sinDec, realT cosDec, realT tanLat)
	Calculate the Parallactic Angle from the pre-calculated trig functions. Result in degrees.
template<typename realT >
realT	mx::astro::parAngRad (realT ha, realT dec, realT lat)
	Calculate the Parallactic Angle, with angles in radians.
template<typename realT >
realT	mx::astro::parAngDeg (realT ha, realT dec, realT lat, bool newflag)
	Calculate the Parallactic Angle, with angles in degrees.

Function Documentation

calcAzEl()

template<typename realT >

int mx::astro::calcAzEl	(	realT &	az,
		realT &	el,
		realT	ha,
		realT	dec,
		realT	lat
	)

Calculates the Azimuth and Elevation for a given Hour-Angle, Declination, and Latitude.

References: J. Meeus "Astronomical Algorithms", 1991; V. Pisacane "Fundamentals of Space Systems", 2nd ed., 2005.

Template Parameters

realT

the real floating point type for calculations

Returns

0 on success

-1 on error

Parameters

[out]	az	the calculated azimuth [degrees]
[out]	el	the calculate elevation [degrees]
[in]	ha	the hour ange [degrees]
[in]	dec	the declination [degrees]
[in]	lat	the latitude [degrees]

Definition at line 208 of file astroDynamics.hpp.

References mx::math::six_fifths().

parAngDeg() [1/2]

template<typename realT >

realT mx::astro::parAngDeg	(	realT	ha,
		realT	dec,
		realT	lat,
		bool	newflag
	)

Calculate the Parallactic Angle, with angles in degrees.

Returns

the parallactic angle in degrees.

Test:

Scenario: calculating parallactic angles [test doc]

Note

2020-Jan-19: re-reordered arguments and added newflag to prevent compilation of current programs so the new order is implemented.

Parameters

[in]	ha	the hour angle, in degrees, negative to the east
[in]	dec	the object declination, in degrees.
[in]	lat	the observer latitude, in degrees.
[in]	newflag	[temporary] to force adaptation of new argument order. Unused, so can be true or false. Added 2020-Jan-19.

Definition at line 298 of file astroDynamics.hpp.

References mx::math::dtor(), mx::astro::parAngRad(), and mx::math::rtod().

parAngDeg() [2/2]

template<typename realT >

realT mx::astro::parAngDeg	(	realT	sinHA,
		realT	cosHA,
		realT	sinDec,
		realT	cosDec,
		realT	tanLat
	)

Calculate the Parallactic Angle from the pre-calculated trig functions. Result in degrees.

Returns

the parallactic angle in degrees.

Parameters

[in]	sinHA	the sine of the target hour angle
[in]	cosHA	the cosine of the target hour angle
[in]	sinDec	the sine of the target declination
[in]	cosDec	the cosine of the target declination
[in]	tanLat	the tangent of the observer latitude

Definition at line 259 of file astroDynamics.hpp.

References mx::astro::parAngRad(), and mx::math::rtod().

Referenced by SCENARIO().

parAngRad() [1/2]

template<typename realT >

realT mx::astro::parAngRad	(	realT	ha,
		realT	dec,
		realT	lat
	)

Calculate the Parallactic Angle, with angles in radians.

Returns

the parallactic angle in radians.

Test:

Scenario: calculating parallactic angles [test doc]

Parameters

[in]	ha	the hour angle, in radians, negative to the east
[in]	dec	the object declination, in radians.
[in]	lat	the observer latitude, in radians.

Definition at line 278 of file astroDynamics.hpp.

References mx::astro::parAngRad().

parAngRad() [2/2]

template<typename realT >

realT mx::astro::parAngRad	(	realT	sinHA,
		realT	cosHA,
		realT	sinDec,
		realT	cosDec,
		realT	tanLat
	)

Calculate the Parallactic Angle from the pre-calculated trig functions. Result in radians.

Returns

the parallactic angle in radians.

Test:

Scenario: calculating parallactic angles [test doc]

Parameters

[in]	sinHA	the sine of the target hour angle
[in]	cosHA	the cosine of the target hour angle
[in]	sinDec	the sine of the target declination
[in]	cosDec	the cosine of the target declination
[in]	tanLat	the tangent of the observer latitude

Definition at line 240 of file astroDynamics.hpp.

Referenced by mx::astro::parAngDeg(), mx::astro::parAngDeg(), and mx::astro::parAngRad().