ObitSkyGeom.c File Reference

ObitSkyGeom function definitions. More...

#include "ObitSkyGeom.h"
#include <math.h>
#include <string.h>
#include <stdio.h>

Defines

#define RAGP   192.25*DG2RAD

#define DECGP   27.40*DG2RAD

#define LONCP   123.00*DG2RAD

Functions

void ObitSkyGeomShiftXY (gdouble ra, gdouble dec, gfloat rotate, gdouble shiftRA, gdouble shiftDec, gfloat *xShift, gfloat *yShift)

Public: Determine shift between two positions.

void ObitSkyGeomXYShift (gdouble ra, gdouble dec, gfloat xShift, gfloat yShift, gfloat rotate, gdouble *shiftRA, gdouble *shiftDec)

Public: Determine result of a shift to a position.

void ObitSkyGeomShiftSIN (gdouble ra, gdouble dec, gfloat rotate, gdouble xra, double xdec, gfloat dxyzc[3])

Public: Get shift parameters for -SIN projection.

void ObitSkyGeomShiftNCP (gdouble ra, gdouble dec, gfloat rotate, gdouble xra, double xdec, gfloat dxyzc[3])

Public: Get shift parameters for -NCP projection.

void ObitSkyGeomNewPos (ObitSkyGeomProj Proj, gdouble ra0, gdouble dec0, gdouble l, gdouble m, gdouble *raout, gdouble *decout, gint *ierr)

Public: Returns astronomical coordinates given direction cosines, projection.

gint ObitSkyGeomCDpos (gfloat xpix, gfloat ypix, gdouble xref, gdouble yref, gfloat xrefpix, gfloat yrefpix, gfloat xinc, gfloat yinc, gfloat rot, gfloat cd1[2], gfloat cd2[2], gchar *type, gdouble *xpos, gdouble *ypos)

Public: Position for pixel coordinates from IRAF style CD matrix.

gint ObitSkyGeomWorldPos (gfloat xpix, gfloat ypix, gdouble xref, gdouble yref, gfloat xrefpix, gfloat yrefpix, gfloat xinc, gfloat yinc, gfloat rot, gchar *type, gdouble *xpos, gdouble *ypos)

Public: accurate position for pixel coordinates.

gint ObitSkyGeomWorldPosLM (gdouble dx, gdouble dy, gdouble xref, gdouble yref, gfloat xinc, gfloat yinc, gfloat rot, gchar *type, gdouble *xpos, gdouble *ypos)

Public: Position for pixel coordinates from offsets from the reference position.

gint ObitSkyGeomXYpix (gdouble xpos, gdouble ypos, gdouble xref, gdouble yref, gfloat xrefpix, gfloat yrefpix, gfloat xinc, gfloat yinc, gfloat rot, gchar *type, gfloat *xpix, gfloat *ypix)

Public: Pixel coordinates for an RA and Dec.

gint ObitSkyGeomCDpix (gdouble xpos, gdouble ypos, gdouble xref, gdouble yref, gfloat xrefpix, gfloat yrefpix, gfloat xinc, gfloat yinc, gfloat rot, gfloat icd1[2], gfloat icd2[2], gchar *type, gfloat *xpix, gfloat *ypix)

Public:pixel coordinates for an RA and Dec from IRAF style CD matrix.

gint ObitSkyGeomXYPixLM (gdouble xpos, gdouble ypos, gdouble xref, gdouble yref, gfloat xinc, gfloat yinc, gfloat rot, gchar *type, gdouble *dx, gdouble *dy)

Public: Coordinate offsets for an RA and Dec.

void ObitSkyGeomBtoJ (gdouble *ra, gdouble *dec)

Public: Precess B1950 to J2000 coordinates.

void ObitSkyGeomJtoB (double *ra, double *dec)

Converts J2000 RA, Dec to B1950 Using method on page B42 of The Astronomical Almanac (1990 ed.) Revised 90/10/15 J.

void ObitSkyGeomEq2Gal (gdouble *RALong, gdouble *DecLat)

Public: Convert Equatorial (B1950) to Galactic coordinates.

void ObitSkyGeomGal2Eq (gdouble *RALong, gdouble *DecLat)

Public: Convert Galactic to Equatorial (B1950).

void ObitSkyGeomEq2Ec (gdouble *RALong, gdouble *DecLat, gfloat epoch)

Public: Convert Equatorial to Ecliptic coordinates.

void ObitSkyGeomEc2Eq (gdouble *RALong, gdouble *DecLat, gfloat epoch)

Public: Convert Ecliptic to Equatorial.

void ObitSkyGeomRADec2Zern (gdouble ra, gdouble dec, gfloat xshift, gfloat yshift, gfloat *xzer, gfloat *yzer, gint *ierr)

Public: Projection to Zernike plane.

Detailed Description

ObitSkyGeom function definitions.

This file contains celestial coordinate utilities

Define Documentation

#define DECGP 27.40*DG2RAD

#define LONCP 123.00*DG2RAD

#define RAGP 192.25*DG2RAD

Function Documentation

void ObitSkyGeomBtoJ ( gdouble * ra,

gdouble * dec

)

Public: Precess B1950 to J2000 coordinates.
J. Condon Taken from FITSview family
Parameters:

ra in/out Right Ascension in degrees

dec in/out Declination in degrees

gint ObitSkyGeomCDpix ( gdouble xpos,

gdouble ypos,

gdouble xref,

gdouble yref,

gfloat xrefpix,

gfloat yrefpix,

gfloat xinc,

gfloat yinc,

gfloat rot,

gfloat icd1[2],

gfloat icd2[2],

gchar * type,

gfloat * xpix,

gfloat * ypix

)

Public:pixel coordinates for an RA and Dec from IRAF style CD matrix.
Note: xinc, yinc, and rot can be derived from cd1 and cd2 and should be compatible with them. Taken from FITSview family
Parameters:

xpos x (RA) coordinate (deg)

ypos y (dec) coordinate (deg)

xref x reference coordinate value (deg)

yref y reference coordinate value (deg)

xrefpix x reference pixel

yrefpix y reference pixel

xinc x coordinate increment (deg)

yinc y coordinate increment (deg)

rot rotation (deg) (from N through E)

type projection type code e.g. "-SIN" Does: -SIN, -TAN, -ARC, -NCP, -GLS, -MER, -AIT projections anything else is linear

cd1 first column of CD matrix

cd2 second column of CD matrix

xpix [out] x pixel number (RA or long without rotation)

ypix [out] y pixel number (dec or lat without rotation)

Returns:
0 if successful otherwise: 1 = angle too large for projection 2 = bad values

gint ObitSkyGeomCDpos ( gfloat xpix,

gfloat ypix,

gdouble xref,

gdouble yref,

gfloat xrefpix,

gfloat yrefpix,

gfloat xinc,

gfloat yinc,

gfloat rot,

gfloat cd1[2],

gfloat cd2[2],

gchar * type,

gdouble * xpos,

gdouble * ypos

)

Public: Position for pixel coordinates from IRAF style CD matrix.
Note: xinc, yinc, and rot can be derived from cd1 and cd2 and should be compatible with them. Taken from FITSview family
Parameters:

xpix x pixel number (RA or long without rotation)

ypix y pixel number (dec or lat without rotation)

xref x reference coordinate value (deg)

yref y reference coordinate value (deg)

xrefpix x reference pixel

yrefpix y reference pixel

xinc x coordinate increment (deg)

yinc y coordinate increment (deg)

rot rotation (deg) (from N through E)

type projection type code e.g. "-SIN" Does: -SIN, -TAN, -ARC, -NCP, -GLS, -MER, -AIT projections anything else is linear

cd1 first column of CD matrix

cd2 second column of CD matrix

xpos [out] x (RA) coordinate (deg)

ypos [out]y (dec) coordinate (deg)

Returns:
0 if successful otherwise: 1 = angle too large for projection;

void ObitSkyGeomEc2Eq ( gdouble * RALong,

gdouble * DecLat,

gfloat epoch

)

Public: Convert Ecliptic to Equatorial.

Parameters:

RALong in/out Right Ascension/longitude in degrees

DecLat in/out Declination.latitude in degrees

epoch Epoch of the coordinates to transform

void ObitSkyGeomEq2Ec ( gdouble * RALong,

gdouble * DecLat,

gfloat epoch

)

Public: Convert Equatorial to Ecliptic coordinates.

Parameters:

RALong in/out Right Ascension/longitude in degrees

DecLat in/out Declination.latitude in degrees

epoch Epoch of the coordinates to transform

void ObitSkyGeomEq2Gal ( gdouble * RALong,

gdouble * DecLat

)

Public: Convert Equatorial (B1950) to Galactic coordinates.

Parameters:

RALong in/out Right Ascension/longitude in degrees

DecLat in/out Declination.latitude in degrees

void ObitSkyGeomGal2Eq ( gdouble * RALong,

gdouble * DecLat

)

Public: Convert Galactic to Equatorial (B1950).

Parameters:

RALong in/out Right Ascension/longitude in degrees

DecLat in/out Declination.latitude in degrees

void ObitSkyGeomJtoB ( double * ra,

double * dec

)

Converts J2000 RA, Dec to B1950 Using method on page B42 of The Astronomical Almanac (1990 ed.) Revised 90/10/15 J.
J. Condon Taken from FITSview family
Parameters:

ra in/out Right Ascension in degrees

dec in/out Declination in degrees

void ObitSkyGeomNewPos ( ObitSkyGeomProj Proj,

gdouble ra0,

gdouble dec0,

gdouble l,

gdouble m,

gdouble * raout,

gdouble * decout,

gint * ierr

)

Public: Returns astronomical coordinates given direction cosines, projection.
the direction cosine l is assumed to be positive to the east; m is positive to the north. the routine works for 4 kinds of projective geometries and for celestial, ecliptic, or galactic coordinate systems. this subroutine always uses an accurate computation. All angles in this subroutine are in radians. Adapted from the AIPSish NEWPOS.FOR.
Parameters:

Proj Projection type (Aitoff and Mercator not supported)

ra0 coordinate reference right ascension (longitude)

dec0 coordinate reference declination (latitude)

l cosine angle of displacement to east

m cosine angle of displacement to north

raout [out] right ascension or longitude at (l,m)

decout [out] declination or latitude at (l,m)

ierr [out] error condition: 0 = ok, 1 = l,m crazy, 2 = bad type, 3 = answer undefined

void ObitSkyGeomRADec2Zern ( gdouble ra,

gdouble dec,

gfloat xshift,

gfloat yshift,

gfloat * xzer,

gfloat * yzer,

gint * ierr

)

Public: Projection to Zernike plane.
The output coordinates are normalized to unity at a 10 deg radius from the reference position. The coordinates are projected onto a plane tangent to the sky at the reference position. Routine translated from the AIPSish ZERGEOM.FOR/RD2ZER
Parameters:

ra Right Ascention of reference position (deg)

dec Declination of reference position (deg)

xshift Shift in X (RA) to desired position (deg)

yshift Shift in Y (Dec) to desired position (deg)

xzer [out] x-coordinate on Zernike plane

yzer [out] y-coordinate on Zernike plane

ierr 0 ok, 1 out of range

void ObitSkyGeomShiftNCP ( gdouble ra,

gdouble dec,

gfloat rotate,

gdouble xra,

double xdec,

gfloat dxyzc[3]

)

Public: Get shift parameters for -NCP projection.
Adapted from the AIPSish SHINCP.FOR.
Parameters:

ra Initial RA in degrees: reference position

dec Initial Declination in degrees

rotate Image rotation in degrees

xra RA of shifted point in degrees

xdec Declination of shifted point in degrees

dxyzc (out) Phase term for Position offsets in x,y,z

void ObitSkyGeomShiftSIN ( gdouble ra,

gdouble dec,

gfloat rotate,

gdouble xra,

double xdec,

gfloat dxyzc[3]

)

Public: Get shift parameters for -SIN projection.
Adapted from the AIPSish SHISIN.FOR.
Parameters:

ra Initial RA in degrees: reference position

dec Initial Declination in degrees

rotate Image rotation in degrees

xra RA of shifted point in degrees

xdec Declination of shifted point in degrees

dxyzc (out) Phase term for Position offsets in x,y,z (2pi turns)

void ObitSkyGeomShiftXY ( gdouble ra,

gdouble dec,

gfloat rotate,

gdouble shiftRA,

gdouble shiftDec,

gfloat * xShift,

gfloat * yShift

)

Public: Determine shift between two positions.
The shift is in (possibly) rotated coordinates. Adopted from the AIPSish SHFTXY.FOR
Parameters:

ra Initial Right Ascension in deg.

dec Initial declination in deg.

rotate Rotation of field, to E from N, deg.

shiftRA Shifted Right Ascension in deg.

shiftDec Shifted declination in deg.

xShift (out) Shift from ra to shiftRA in deg.

yShift (out) Shift from dec to shiftDec in deg.

gint ObitSkyGeomWorldPos ( gfloat xpix,

gfloat ypix,

gdouble xref,

gdouble yref,

gfloat xrefpix,

gfloat yrefpix,

gfloat xinc,

gfloat yinc,

gfloat rot,

gchar * type,

gdouble * xpos,

gdouble * ypos

)

Public: accurate position for pixel coordinates.
Taken from FITSview family
Parameters:

xpix x pixel number (RA or long without rotation)

ypix y pixel number (dec or lat without rotation)

xref x reference coordinate value (deg)

yref y reference coordinate value (deg)

xrefpix x reference pixel

yrefpix y reference pixel

xinc x coordinate increment (deg)

yinc y coordinate increment (deg)

rot rotation (deg) (from N through E)

type projection type code e.g. "-SIN" Does: -SIN, -TAN, -ARC, -NCP, -GLS, -MER, -AIT projections anything else is linear

xpos [out] x (RA) coordinate (deg)

ypos [out]y (dec) coordinate (deg)

Returns:
0 if successful otherwise: 1 = angle too large for projection;

gint ObitSkyGeomWorldPosLM ( gdouble dx,

gdouble dy,

gdouble xref,

gdouble yref,

gfloat xinc,

gfloat yinc,

gfloat rot,

gchar * type,

gdouble * xpos,

gdouble * ypos

)

Public: Position for pixel coordinates from offsets from the reference position.
Taken from FITSview family
Parameters:

dx x coordinate offset (RA or long)

dy y coordinate offset (dec or lat)

xref x reference coordinate value (deg)

yref y reference coordinate value (deg

xinc x coordinate increment (deg)

yinc y coordinate increment (deg)

rot rotation (deg) (from N through E)

type projection type code e.g. "-SIN" Does: -SIN, -TAN, -ARC, -NCP, -GLS, -MER, -AIT projections anything else is linear

xpos [out] x (RA) coordinate (deg)

ypos [out] y (dec) coordinate (deg)

Returns:
0 if successful otherwise: 1 = angle too large for projection;

gint ObitSkyGeomXYpix ( gdouble xpos,

gdouble ypos,

gdouble xref,

gdouble yref,

gfloat xrefpix,

gfloat yrefpix,

gfloat xinc,

gfloat yinc,

gfloat rot,

gchar * type,

gfloat * xpix,

gfloat * ypix

)

Public: Pixel coordinates for an RA and Dec.

Parameters:

xpos x (RA) coordinate (deg)

ypos y (dec) coordinate (deg)

xref x reference coordinate value (deg)

yref y reference coordinate value (deg)

xrefpix x reference pixel

yrefpix y reference pixel

xinc x coordinate increment (deg)

yinc y coordinate increment (deg)

rot rotation (deg) (from N through E)

type projection type code e.g. "-SIN" Does: -SIN, -TAN, -ARC, -NCP, -GLS, -MER, -AIT projections anything else is linear

xpix [out] x pixel number (RA or long without rotation)

ypix [out] y pixel number (dec or lat without rotation)

Returns:
0 if successful otherwise: 1 = angle too large for projection 2 = bad values

gint ObitSkyGeomXYPixLM ( gdouble xpos,

gdouble ypos,

gdouble xref,

gdouble yref,

gfloat xinc,

gfloat yinc,

gfloat rot,

gchar * type,

gdouble * dx,

gdouble * dy

)

Public: Coordinate offsets for an RA and Dec.

Parameters:

xpos x (RA) coordinate (deg)

ypos y (dec) coordinate (deg)

xref x reference coordinate value (deg)

yref y reference coordinate value (deg)

xrefpix x reference pixel

yrefpix y reference pixel

xinc x coordinate increment (deg)

yinc y coordinate increment (deg)

rot rotation (deg) (from N through E)

type projection type code e.g. "-SIN" Does: -SIN, -TAN, -ARC, -NCP, -GLS, -MER, -AIT projections anything else is linear

xpix [out] x pixel number (RA or long without rotation)

ypix [out] y pixel number (dec or lat without rotation)

Returns:
0 if successful otherwise: 1 = angle too large for projection 2 = bad values

void ObitSkyGeomXYShift ( gdouble ra,

gdouble dec,

gfloat xShift,

gfloat yShift,

gfloat rotate,

gdouble * shiftRA,

gdouble * shiftDec

)

Public: Determine result of a shift to a position.
The shift is in (possibly) rotated coordinates. Adopted from the AIPSish XYSHFT.FOR
Parameters:

ra Initial Right Ascension in deg.

dec Initial declination in deg.

xShift Shift from ra to shiftRA in deg.

yShift Shift from dec to shiftDec in deg.

rotate Rotation of field, to E from N, deg.

shiftRA (out) Shifted Right Ascension in deg.

shiftDec (out) Shifted declination in deg.

Generated on Fri Aug 31 22:13:07 2007 for Obit by

1.3.9.1


Defines
#define	RAGP 192.25*DG2RAD
#define	DECGP 27.40*DG2RAD
#define	LONCP 123.00*DG2RAD
Functions
void	ObitSkyGeomShiftXY (gdouble ra, gdouble dec, gfloat rotate, gdouble shiftRA, gdouble shiftDec, gfloat xShift, gfloat yShift)
	Public: Determine shift between two positions.
void	ObitSkyGeomXYShift (gdouble ra, gdouble dec, gfloat xShift, gfloat yShift, gfloat rotate, gdouble shiftRA, gdouble shiftDec)
	Public: Determine result of a shift to a position.
void	ObitSkyGeomShiftSIN (gdouble ra, gdouble dec, gfloat rotate, gdouble xra, double xdec, gfloat dxyzc[3])
	Public: Get shift parameters for -SIN projection.
void	ObitSkyGeomShiftNCP (gdouble ra, gdouble dec, gfloat rotate, gdouble xra, double xdec, gfloat dxyzc[3])
	Public: Get shift parameters for -NCP projection.
void	ObitSkyGeomNewPos (ObitSkyGeomProj Proj, gdouble ra0, gdouble dec0, gdouble l, gdouble m, gdouble raout, gdouble decout, gint *ierr)
	Public: Returns astronomical coordinates given direction cosines, projection.
gint	ObitSkyGeomCDpos (gfloat xpix, gfloat ypix, gdouble xref, gdouble yref, gfloat xrefpix, gfloat yrefpix, gfloat xinc, gfloat yinc, gfloat rot, gfloat cd1[2], gfloat cd2[2], gchar type, gdouble xpos, gdouble *ypos)
	Public: Position for pixel coordinates from IRAF style CD matrix.
gint	ObitSkyGeomWorldPos (gfloat xpix, gfloat ypix, gdouble xref, gdouble yref, gfloat xrefpix, gfloat yrefpix, gfloat xinc, gfloat yinc, gfloat rot, gchar type, gdouble xpos, gdouble *ypos)
	Public: accurate position for pixel coordinates.
gint	ObitSkyGeomWorldPosLM (gdouble dx, gdouble dy, gdouble xref, gdouble yref, gfloat xinc, gfloat yinc, gfloat rot, gchar type, gdouble xpos, gdouble *ypos)
	Public: Position for pixel coordinates from offsets from the reference position.
gint	ObitSkyGeomXYpix (gdouble xpos, gdouble ypos, gdouble xref, gdouble yref, gfloat xrefpix, gfloat yrefpix, gfloat xinc, gfloat yinc, gfloat rot, gchar type, gfloat xpix, gfloat *ypix)
	Public: Pixel coordinates for an RA and Dec.
gint	ObitSkyGeomCDpix (gdouble xpos, gdouble ypos, gdouble xref, gdouble yref, gfloat xrefpix, gfloat yrefpix, gfloat xinc, gfloat yinc, gfloat rot, gfloat icd1[2], gfloat icd2[2], gchar type, gfloat xpix, gfloat *ypix)
	Public:pixel coordinates for an RA and Dec from IRAF style CD matrix.
gint	ObitSkyGeomXYPixLM (gdouble xpos, gdouble ypos, gdouble xref, gdouble yref, gfloat xinc, gfloat yinc, gfloat rot, gchar type, gdouble dx, gdouble *dy)
	Public: Coordinate offsets for an RA and Dec.
void	ObitSkyGeomBtoJ (gdouble ra, gdouble dec)
	Public: Precess B1950 to J2000 coordinates.
void	ObitSkyGeomJtoB (double ra, double dec)
	Converts J2000 RA, Dec to B1950 Using method on page B42 of The Astronomical Almanac (1990 ed.) Revised 90/10/15 J.
void	ObitSkyGeomEq2Gal (gdouble RALong, gdouble DecLat)
	Public: Convert Equatorial (B1950) to Galactic coordinates.
void	ObitSkyGeomGal2Eq (gdouble RALong, gdouble DecLat)
	Public: Convert Galactic to Equatorial (B1950).
void	ObitSkyGeomEq2Ec (gdouble RALong, gdouble DecLat, gfloat epoch)
	Public: Convert Equatorial to Ecliptic coordinates.
void	ObitSkyGeomEc2Eq (gdouble RALong, gdouble DecLat, gfloat epoch)
	Public: Convert Ecliptic to Equatorial.
void	ObitSkyGeomRADec2Zern (gdouble ra, gdouble dec, gfloat xshift, gfloat yshift, gfloat xzer, gfloat yzer, gint *ierr)
	Public: Projection to Zernike plane.