Astrometry Functions
[Astronomy Functions]

Collaboration diagram for Astrometry Functions:

Files
file	psAstrometry.h
	This file defines the basic types for astronomical coordinate transformation.
Data Structures
struct	psGrommit
	Wallace's Grommit. More...
struct	psFixedPattern
	Fixed Pattern Corrections. More...
struct	psReadout
	Readout data structure. More...
struct	psCell
	Cell data structure. More...
struct	psChip
	Chip data structure. More...
struct	psFPA
	A Focal-Plane. More...
struct	psObservatory
	Observatory Information. More...
struct	psExposure
	Exposure Information. More...
Typedefs
typedef psChip	psChip
	Chip data structure.
typedef psFPA	psFPA
	A Focal-Plane.
typedef psExposure	psExposure
	Exposure Information.
Functions
psFixedPattern *	psFixedPatternAlloc (double x0, double y0, double xScale, double yScale, const psImage *x, const psImage *y)
	Allocator for psFixedPattern struct.
psExposure *	psExposureAlloc (double ra, double dec, double hourAngle, double zenithDistance, double azimuth, const psTime *time, float rotAngle, float temperature, float pressure, float humidity, float exposureTime, float wavelength, const psObservatory *observatory)
	Allocator for psExposure.
psObservatory *	psObservatoryAlloc (const char *name, double latitude, double longitude, double height, double tlr)
	Allocator for psObservatory.
psFPA *	psFPAAlloc (psS32 nChips, const psExposure *exp)
	Allocator for psFPA.
psChip *	psChipAlloc (psS32 nCells, psFPA *parentFPA)
	Allocates a psChip.
psCell *	psCellAlloc (psS32 nReadouts, psChip *parentChip)
	Allocates a psCell.
psReadout *	psReadoutAlloc ()
	Allocates a psReadout.
psGrommit *	psGrommitAlloc (const psExposure *exp)
	Allocates a Wallace's Grommit structure.
psCell *	psCellInFPA (const psPlane *coord, const psFPA *FPA)
	Find cooresponding cell for given FPA coordinate.
psChip *	psChipInFPA (const psPlane *coord, const psFPA *FPA)
	Find cooresponding chip for given FPA coordinate.
psCell *	psCellInChip (const psPlane *coord, const psChip *chip)
	Find cooresponding cell for given Chip coordinate.
psPlane *	psCoordCellToChip (psPlane *out, const psPlane *in, const psCell *cell)
	Translate a cell coordinate into a chip coordinate.
psPlane *	psCoordChipToFPA (psPlane *out, const psPlane *in, const psChip *chip)
	Translate a chip coordinate into a FPA coordinate.
psPlane *	psCoordFPAToTP (psPlane *out, const psPlane *in, double color, double magnitude, const psFPA *fpa)
	Translate a FPA coordinate into a Tangent Plane coordinate.
psSphere *	psCoordTPToSky (psSphere *out, const psPlane *in, const psGrommit *grommit)
	Translate a Tangent Plane coordinate into a Sky coordinate.
psPlane *	psCoordCellToFPA (psPlane *out, const psPlane *in, const psCell *cell)
	Translate a cell coordinate into a FPA coordinate.
psSphere *	psCoordCellToSky (psSphere *out, const psPlane *in, double color, double magnitude, const psCell *cell)
	Translate a cell coordinate into a Sky coordinate.
psSphere *	psCoordCellToSkyQuick (psSphere *out, const psPlane *in, const psCell *cell)
	Translate a cell coordinate into a Sky coordinate using a 'quick and dirty' method.
psPlane *	psCoordSkyToTP (psPlane *out, const psSphere *in, const psGrommit *grommit)
	Translate a Sky coordinate into a Tangent Plane coordinate.
psPlane *	psCoordTPToFPA (psPlane *out, const psPlane *in, double color, double magnitude, const psFPA *fpa)
	Translate a Tangent Plane coordinate into a FPA coordinate.
psPlane *	psCoordFPAToChip (psPlane *out, const psPlane *in, const psChip *chip)
	Translate a FPA coordinate into a chip coordinate.
psPlane *	psCoordChipToCell (psPlane *out, const psPlane *in, const psCell *cell)
	Translate a chip coordinate into a cell coordinate.
psPlane *	psCoordSkyToCell (psPlane *out, const psSphere *in, double color, double magnitude, const psCell *cell)
	Translate a sky coordinate into a cell coordinate.
psPlane *	psCoordSkyToCellQuick (psPlane *out, const psSphere *in, const psCell *cell)
	Translate a sky coordinate into a cell coordinate using a 'quick and dirty' method.

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Typedef Documentation

typedef struct psChip psChip

Chip data structure. A chip consists of one or more cells (according to the number of amplifiers on the CCD). It contains a pointer to the chip's metadata, and a pointer to the parent focal plane. For astrometry, it contains a coordinate transform from the chip to the focal plane, and vis-versa.

typedef struct psExposure psExposure

Exposure Information. Several quantities from the telescope in order to make a first guess at the astrometric solution. From these quantities, further quantities can be derivedand stored for later use.

typedef struct psFPA psFPA

A Focal-Plane. A focal plane consists of one or more chips (according to the number of contiguous silicon). It contains pointers to the focal-plane's metadata and the exposure information. For astrometry, it contains a transformation from the focal plane to the tangent plane and the fixed pattern residuals. Since colors are involved in the transformation, it is necessary to specify the color the transformation is defined. We also include some values to characterize the quality of the transformation: the root square deviation for the x and y transformation fits, and the chi-squared for the transformation fit.

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Function Documentation

psCell* psCellAlloc (  psS32  nReadouts, psChip *  parentChip )

Allocates a psCell. The constructor shall make an empty psCell, with the nReadouts allocated pointers to psReadouts being set to NULL; all other pointers in the structure shall be initialized to NULL. Returns: psCell* newly allocated psCell Parameters: nReadouts  number of readouts in cell parentChip  parent Chip

psCell* psCellInChip (  const psPlane *  coord, const psChip *  chip )

Find cooresponding cell for given Chip coordinate. Returns: psCell* the cell cooresponding to coord Parameters: coord  the coordinate in Chip plane chip  the chip to search for the cell

psCell* psCellInFPA (  const psPlane *  coord, const psFPA *  FPA )

Find cooresponding cell for given FPA coordinate. Returns: psCell* the cell cooresponding to the coord in FPA Parameters: coord  the coordinate in FPA plane FPA  the FPA to search for the cell

psChip* psChipAlloc (  psS32  nCells, psFPA *  parentFPA )

Allocates a psChip. This allocator shall make an empty psChip, with the nCells allocated pointers to psCells being set to NULL; all other pointers in the structure shall be initialized to NULL. Returns: psChip* newly allocated psChip Parameters: nCells  number of cells in Chip parentFPA  parent FPA

psChip* psChipInFPA (  const psPlane *  coord, const psFPA *  FPA )

Find cooresponding chip for given FPA coordinate. Returns: psChip* the chip cooresponding to coord Parameters: coord  the coordinate in FPA plane FPA  the FPA to search for the cell

psPlane* psCoordCellToChip (  psPlane *  out, const psPlane *  in, const psCell *  cell )

Translate a cell coordinate into a chip coordinate. Returns: psPlane* the resulting chip coordinate Parameters: out  a plane struct to recycle. If NULL, a new struct is created in  the coordinate within Cell cell  the Cell in interest

psPlane* psCoordCellToFPA (  psPlane *  out, const psPlane *  in, const psCell *  cell )

Translate a cell coordinate into a FPA coordinate. Returns: psPlane* the resulting FPA coordinate Parameters: out  a plane struct to recycle. If NULL, a new struct is created in  the coordinate within cell cell  the cell in interest

psSphere* psCoordCellToSky (  psSphere *  out, const psPlane *  in, double  color, double  magnitude, const psCell *  cell )

Translate a cell coordinate into a Sky coordinate. Returns: psSphere* the resulting Sky coordinate Parameters: out  a sphere struct to recycle. If NULL, a new struct is created in  the coordinate within cell color  Color of source magnitude  Magnitude of source cell  the cell in interest

psSphere* psCoordCellToSkyQuick (  psSphere *  out, const psPlane *  in, const psCell *  cell )

Translate a cell coordinate into a Sky coordinate using a 'quick and dirty' method. Returns: psSphere* the resulting Sky coordinate Parameters: out  a sphere struct to recycle. If NULL, a new struct is created in  the coordinate within cell cell  the cell in interest

psPlane* psCoordChipToCell (  psPlane *  out, const psPlane *  in, const psCell *  cell )

Translate a chip coordinate into a cell coordinate. Returns: psPlane* the resulting cell coordinate Parameters: out  a plane struct to recycle. If NULL, a new struct is created in  the Chip coordinate cell  the cell of interest

psPlane* psCoordChipToFPA (  psPlane *  out, const psPlane *  in, const psChip *  chip )

Translate a chip coordinate into a FPA coordinate. Returns: psPlane* the resulting FPA coordinate Parameters: out  a plane struct to recycle. If NULL, a new struct is created in  the coordinate within Chip chip  the chip in interest

psPlane* psCoordFPAToChip (  psPlane *  out, const psPlane *  in, const psChip *  chip )

Translate a FPA coordinate into a chip coordinate. Returns: psPlane* the resulting chip coordinate Parameters: out  a plane struct to recycle. If NULL, a new struct is created in  the FPA coordinate chip  the chip of interest

psPlane* psCoordFPAToTP (  psPlane *  out, const psPlane *  in, double  color, double  magnitude, const psFPA *  fpa )

Translate a FPA coordinate into a Tangent Plane coordinate. Returns: psPlane* the resulting Tangent Plane coordinate Parameters: out  a plane struct to recycle. If NULL, a new struct is created in  the coordinate within FPA color  Color of source magnitude  Magnitude of source fpa  the FPA in interest

psPlane* psCoordSkyToCell (  psPlane *  out, const psSphere *  in, double  color, double  magnitude, const psCell *  cell )

Translate a sky coordinate into a cell coordinate. Returns: psPlane* the resulting cell coordinate Parameters: out  a plane struct to recycle. If NULL, a new struct is created in  the Sky coordinate color  Color of source magnitude  Magnitude of source cell  the cell of interest

psPlane* psCoordSkyToCellQuick (  psPlane *  out, const psSphere *  in, const psCell *  cell )

Translate a sky coordinate into a cell coordinate using a 'quick and dirty' method. Returns: psPlane* the resulting cell coordinate Parameters: out  a plane struct to recycle. If NULL, a new struct is created in  the Sky coordinate cell  the cell of interest

psPlane* psCoordSkyToTP (  psPlane *  out, const psSphere *  in, const psGrommit *  grommit )

Translate a Sky coordinate into a Tangent Plane coordinate. Returns: psPlane* the resulting Tangent Plane coordinate Parameters: out  a plane struct to recycle. If NULL, a new struct is created in  the sky coordinate grommit  the grommit

psPlane* psCoordTPToFPA (  psPlane *  out, const psPlane *  in, double  color, double  magnitude, const psFPA *  fpa )

Translate a Tangent Plane coordinate into a FPA coordinate. Returns: psPlane* the resulting FPA coordinate Parameters: out  a plane struct to recycle. If NULL, a new struct is created in  the coordinate within tangent plane color  Color of source magnitude  Magnitude of source fpa  the FPA of interest

psSphere* psCoordTPToSky (  psSphere *  out, const psPlane *  in, const psGrommit *  grommit )

Translate a Tangent Plane coordinate into a Sky coordinate. Returns: psSphere* the resulting Sky coordinate Parameters: out  a sphere struct to recycle. If NULL, a new struct is created in  the coordinate within Tangent Plane grommit  the grommit of the tangent plane

psExposure* psExposureAlloc (  double  ra, double  dec, double  hourAngle, double  zenithDistance, double  azimuth, const psTime *  time, float  rotAngle, float  temperature, float  pressure, float  humidity, float  exposureTime, float  wavelength, const psObservatory *  observatory )

Allocator for psExposure. We need several quantities from the telescope in order to make a first guess at the astrometric solution. From these quantities, further quantities can be derived and stored for later use. Returns: psExposure* New psExposure struct Parameters: ra  Telescope boresight, right ascention dec  Telescope boresight, declination hourAngle  Hour angle zenithDistance  Zenith distance azimuth  Azimuth time  time of observation rotAngle  Rotator position angle temperature  Temperature pressure  Pressure humidity  Relative humidity exposureTime  Exposure time wavelength  wavelength observatory  Observatory data

psFixedPattern* psFixedPatternAlloc (  double  x0, double  y0, double  xScale, double  yScale, const psImage *  x, const psImage *  y )

Allocator for psFixedPattern struct. Allocates a new psFixedPattern struct with the attributes coorsponding to the parameters set to the said input values. Returns: psFixedPattern* New psFixedPattern struct. Parameters: x0  X Position of 0,0 corner on focal plane y0  Y Position of 0,0 corner on focal plane xScale  Scale of the grid in x direction yScale  Scale of the grid in x direction x  The grid of offsets in x y  The grid of offsets in y

psFPA* psFPAAlloc (  psS32  nChips, const psExposure *  exp )

Allocator for psFPA. This function shall make an empty psFPA, with the nChips allocated pointers to psChips being set to NULL; all other pointers in the structure shall be initialized to NULL, apart from the grommit, which shall be constructed on the basis of the exp parameter. Returns: psFPA* a newly allocated psFPA Parameters: nChips  number of chips in the FPA exp  the exposure information

psGrommit* psGrommitAlloc (  const psExposure *  exp  )

Allocates a Wallace's Grommit structure. The psGrommit is calculated from telescope information for the particular exposure. Returns: psGrommit* New grommit structure. Parameters: exp  the cooresponding exposure structure.

psObservatory* psObservatoryAlloc (  const char *  name, double  latitude, double  longitude, double  height, double  tlr )

Allocator for psObservatory. This function shall construct a new psObservatory with attributes cooresponding to the function parameters. Returns: psObservatory* new psObservatory struct Parameters: name  Name of observatory latitude  Latitude of observatory, east positive longitude  Longitude of observatory height  Height of observatory tlr  Tropospheric Lapse Rate

psReadout* psReadoutAlloc (   )

Allocates a psReadout. All pointers in the structure other than the image shall be initialized to NULL. Returns: psReadout* newly allocated psReadout with all internal pointers set to NULL

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