Changeset 251 for trunk/archive/pslib/include/psAstrom.h
- Timestamp:
- Mar 17, 2004, 2:53:17 PM (22 years ago)
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- 1 edited
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trunk/archive/pslib/include/psAstrom.h (modified) (2 diffs)
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trunk/archive/pslib/include/psAstrom.h
r247 r251 1 # if !defined(PS_ASTROM_H)2 # define PS_ASTROM_H1 # if !defined(PS_ASTROM_H) 2 # define PS_ASTROM_H 3 3 4 4 /** \file psAstrom.h … … 7 7 */ 8 8 9 /** Astrometric solution for an OTA. 10 * There are five coordinate frames that we need to worry about: 11 * 1. Cell frame: x,y in pixels (raw coordinates; lower-left pixel center is 0.5,0.5 TBR) 12 * 2. Chip frame: X,Y in pixels 13 * 3. FPA frame: P,Q in microns 14 * 4. Tangent plane: L,M in arcsec (TBR - angles or linear?) from the telescope boresight. 15 * 5. Sky frame: R,D in degrees (TBR - radians?) 16 * 17 * 1 <--> 2: cell.coords : a 2-D linear transformation : rotation, scaling, offset, (skew) 18 * 2 <--> 3: chip.coords : a 2-D cubic (max) transform : specifies how the chips are mounted on the focal plane. 19 * 3 <--> 4: fpa.distort : a 2-D quartic (?) transform : specifies the distortions in the optics 20 * 4 <--> 5: fpa.SLpars : SLALib parameters generated based on the telescope, ra, dec, time, etc from exposure info 21 */ 22 23 /** Information needed (by SLALIB) to convert Apparent to Observed Position */ 24 typedef struct { 25 double latitude; ///< geodetic latitude (radians) 26 double sinLat, cosLat; ///< sine and cosine of geodetic latitude 27 double abberationMag; ///< magnitude of diurnal aberration vector 28 double height; ///< height (HM) 29 double temperature; ///< ambient temperature (TDK) 30 double pressure; ///< pressure (PMB) 31 double humidity; ///< relative humidity (RH) 32 double wavelength; ///< wavelength (WL) 33 double lapseRate; ///< lapse rate (TLR) 34 double refractA, refractB; ///< refraction constants A and B (radians) 35 double longitudeOffset; ///< longitude + eqn of equinoxes + ``sidereal UT'' (radians) 36 double siderealTime; ///< local apparent sidereal time (radians) 37 } psGrommit; 38 39 /** Exposure information from the telescope */ 40 typedef struct { 41 // Telescope longitude, latitude and height are stored separately, since they don't change with pointing 42 double ra, dec; //!< Telescope boresight 43 double ha; //!< Hour angle 44 double zd; //!< Zenith distance 45 double az; //!< Azimuth 46 double lst; //!< Local Sidereal Time 47 float mjd; //!< MJD of observation 48 float rotAngle; //!< Rotator position angle 49 float temp; //!< Air temperature, for estimating refraction 50 float pressure; //!< Air pressure, for calculating refraction 51 float humidity; //!< Relative humidity, for calculating refraction 52 float exptime; //!< Exposure time 53 /* Derived quantities */ 54 float posAngle; //!< Position angle 55 float parallactic; //!< Parallactic angle 56 float airmass; //!< Airmass, calculated from zenith distance 57 float pf; //!< Parallactic factor 58 char *cameraName; ///< name of camera which provided exposure 59 char *telescopeName; ///< name of telescope which provided exposure 60 psGrommit *grommit; //!< Data needed to convert from the sky to the tangent plane 61 } psExposure; 62 63 /** a Focal plane array: a collection of chips. Not all chips in a camera need to be listed in an instance of 64 * psFPA. 65 */ 66 typedef struct { 67 int nChips; ///< Number of Cells assigned 68 int nAlloc; ///< Number of Cells available 69 psChip *chips; ///< Chips in the Focal Plane Array 70 psMetaData *md; ///< FPA-level metadata 71 psDistort *TPtoFP; ///< Transformation term from 72 psDistort *FPtoTP; ///< Transformation term from 73 psExposure *exp; ///< information about this exposure 74 psMatrix *dx, *dy; //!< Focal Plane fixed pattern residual offsets 75 psPhotSystem colorPlus, colorMinus; ///< Colour reference 76 float rmsX, rmsY; //!< Dispersion in astrometric solution 77 float chi2; //!< chi^2 of astrometric solution 78 } psFPA; 79 80 /** a Chip: a collection of cells. Not all valid cells in a chip need to be listed in an 81 * instance of psChip. 82 */ 83 typedef struct { 84 int nCells; ///< Number of Cells assigned 85 psCell *cells; ///< Cells in the Chip 86 psMetaData *md; ///< Chip-level metadata 87 88 psCoordXform *chipToFPA; ///< Transformations from chip coordinates to FPA coordinates 89 psCoordXform *FPAtoChip; ///< Transformations from chip coordinates to FPA coordinates 90 91 psFPA *parentFPA; ///< FPA which contains this chip 92 } psChip; 93 94 /** a Cell: a collection of pixels. 95 */ 96 typedef struct { 97 psObjectTable *objects; ///< objects derived from cell 98 psImage *image; ///< imaging area of cell 99 psImage *overscan; ///< bias region (subimage) of cell 100 psMetaData *md; ///< Cell-level metadata 101 102 psCoordXform *cellToChip; ///< Transformations from cell coordinates to chip coordinates 103 psCoordXform *cellToFPA; ///< Transformations from cell coordinates to FPA coordinates 104 105 psChip *parentChip; ///< chip which contains this cell 106 } psCell; 107 108 /*** Functions ***********************************************************************/ 109 9 110 /***********************************************************************************************************/ 10 111 11 /** Exposure information from the telescope */ 12 typedef struct { 13 // Telescope longitude, latitude and height are stored separately, since they don't change with pointing 14 double ra, dec; //!< Telescope boresight 15 double ha; //!< Hour angle 16 double zd; //!< Zenith distance 17 double az; //!< Azimuth 18 double lst; //!< Local Sidereal Time 19 float mjd; //!< MJD of observation 20 float rotAngle; //!< Rotator position angle 21 float temp; //!< Air temperature, for estimating refraction 22 float pressure; //!< Air pressure, for calculating refraction 23 float humidity; //!< Relative humidity, for calculating refraction 24 float exptime; //!< Exposure time 25 /* Derived quantities */ 26 float posAngle; //!< Position angle 27 float parallactic; //!< Parallactic angle 28 float airmass; //!< Airmass, calculated from zenith distance 29 float pf; //!< Parallactic factor 30 } psExposure; 112 /* Calculating and applying astrometric solutions */ 113 114 /** returns Cell in Chip which contains the given point */ 115 int 116 psCellInChip (psChip *chip, ///< chip description 117 psCoords *coords ///< coordinate to find 118 ); 119 120 /** returns the Cell coords for the specified Cell corresponding to the given Chip coords */ 121 psCoords 122 psChipCoordsOnCell (psCell *cell, ///< source cell for coordinate 123 psCoords *coords ///< coordinate of interest 124 ); 125 126 /** returns the Cell coords for the specified Cell corresponding to the given Chip coords */ 127 psCoords 128 psCellCoordsInChip (psChip *chip, ///< 129 int cell, ///< 130 psCoords *coords ///< 131 ); 132 133 /** returns Chip in FPA which contains the given point */ 134 int 135 psChipInFPA (psFPA *fpa, ///< 136 psCoords *coords ///< 137 ); 138 139 /** returns the Chip coords for the specified Chip corresponding to the given FPA coords */ 140 psCoords 141 psFPACoordsOnChip (psChip *chip, ///< 142 psCoords *coords ///< 143 ); 144 145 /** returns the Chip coords for the specified Chip corresponding to the given FPA coords */ 146 psCoords 147 psChipCoordsInFPA (psFPA *fpa, ///< 148 int chip, ///< 149 psCoords *coords ///< 150 ); 151 152 /** Convert (RA,Dec) to (cell#,x,y) */ 153 psCoords * 154 psSkyToFPA(psFPA *fpa, //!< OTA details 155 psCoords *coords //!< Position on the sky 156 ); 157 158 /** Convert (cell#,x,y) to (RA,Dec) */ 159 psCoords * 160 psFPAToSky(psFPA *fpa, //!< OTA details 161 psCoords *coords //!< Position on the sky 162 ); 163 164 /** Convert (RA,Dec) to (cell#,x,y) */ 165 psCoords * 166 psSkyToTP(psExposure *exp, //!< OTA details 167 psCoords *coords //!< Position on the sky 168 ); 169 170 /** Convert (RA,Dec) to (cell#,x,y) */ 171 psCoords * 172 psTPtoSky(psExposure *exp, //!< OTA details 173 psCoords *coords //!< Position on the sky 174 ); 175 176 /** Get the airmass for a given position and sidereal time */ 177 float 178 psGetAirmass(psCoords *coords, //!< Position on the sky 179 double siderealTime //!< Sidereal time 180 ); 181 182 /** Get the parallactic angle for a given position and sidereal time */ 183 float 184 psGetParallactic(psCoords *coords, //!< Position on the sky 185 double siderealTime //!< Sidereal time 186 ); 187 188 /** Estimate atmospheric refraction, along the parallactic */ 189 float 190 psGetRefraction(float colour, //!< Colour of object 191 psColourRef colourRef, //!< Colour reference 192 psExposure *exp //!< Telescope pointing information, for airmass, temp and pressure 193 ); 194 195 /** Fit astrometric solution to list of (chip#,x,y) and (RA,Dec) */ 196 int 197 psFitAstrom(psOTADescription *restrict ota, //!< Initial guess for coefficients 198 const psOTAPosArray *restrict detector, //!< Positions on OTA (chip#,x,y) 199 const psSkyPosArray *restrict sky, //!< Positions on the sky (RA,Dec) 200 const psExposure *exp //!< Telescope pointing information, for airmass, parallactic angle 201 //!< which may help set the astrometric solution 202 ); 203 204 /*** Constructors / Destructors ******************************************************/ 31 205 32 206 /** Constructor */ 33 207 psExposure * 34 psExposureAlloc(double ra, double dec, 35 double ha,//!< Hour angle36 double zd,//!< Zenith distance37 double az,//!< Azimuth38 double lst,//!< Local Sidereal Time39 float mjd,//!< MJD40 float rotAngle,//!< Rotator position angle41 float temp,//!< Temperature42 float pressure,//!< Pressure43 float humidity,//!< Relative humidity44 float exptime//!< Exposure time45 208 psExposureAlloc(double ra, double dec, //!< Telescope boresight 209 double ha, //!< Hour angle 210 double zd, //!< Zenith distance 211 double az, //!< Azimuth 212 double lst, //!< Local Sidereal Time 213 float mjd, //!< MJD 214 float rotAngle, //!< Rotator position angle 215 float temp, //!< Temperature 216 float pressure, //!< Pressure 217 float humidity, //!< Relative humidity 218 float exptime //!< Exposure time 219 ); 46 220 47 221 /** Destructor */ 48 222 void 49 223 psExposureFree(psExposure *restrict myExp //!< Object to destroy 50 ); 51 52 53 /***********************************************************************************************************/ 54 55 /** Cell details: specifies how the cell is mounted on its parent OTA */ 56 typedef struct { 57 double x, y; //!< Position of cell in its OTA. Specifies the position of the 58 //!< (imaginary) pixel (0,0) 59 double xErr, yErr; //!< Error in position of cell in the OTA. 60 double rotation; //!< Rotation of cell in its OTA. Specified from +x through +y 61 int xSize, ySize; //!< Number of pixels in x and y 62 double scale; //!< Relative pixel scales, if CCD pitch varies over the OTA. Specify 63 //!< a positive scale for a left-handed coordinate system, negative 64 //!< for right. If NULL, then every chip has identical scale, and 65 //!< system is left-handed. 66 } psCellDescription; 67 68 /** Constructor */ 69 psCellDescription * 70 psCellDescriptionAlloc(void); 71 72 /** Destructor */ 73 void 74 psCellDescriptionFree(psCellDescription *restrict myCell //!< Cell description to destroy 75 ); 76 77 /***********************************************************************************************************/ 78 79 /** Array of cell descriptions */ 80 typedef struct { 81 psType type; //!< Type of data. THIS STRUCT ELEMENT MUST BE FIRST IN THE STRUCT! 82 int size; //!< Total number of elements available 83 int n; //!< Number of elements in use 84 double *arr; //!< The array data 85 } psCellDescriptionArray; 86 87 /** Constructor */ 88 psCellDescriptionArray *psCellDescriptionArrayAlloc(int s, //!< Total number of elements to make available 89 int n //!< Number of elements that will be used 90 ); 91 /** Reallocator */ 92 psCellDescriptionArray *psCellDescriptionArrayRealloc(psCellDescriptionArray *myArray, //!< Array to 93 //!< reallocate 94 int s //!< Total number of elements to make available 95 ); 96 /** Destructor */ 97 void psCellDescriptionArrayFree(psCellDescriptionArray *restrict myArray //!< Array to free 98 ); 99 100 /***********************************************************************************************************/ 101 102 /** OTA details: specifies how the OTA is mounted on the focal plane */ 103 typedef struct { 104 double x, y; //!< Position of OTA on the focal plane. Specifies the position of 105 //!< the bottom left-hand corner. 106 double xErr, yErr; //!< Error in the position of the OTA. 107 double rotation; //!< Rotation of OTA on the focal plane. Specified from +x through +y 108 psCellDescriptionArray *restrict cells; //!< Cell descriptions 109 struct psOTAAstrom *astrom; //!< OTA astrometry 110 psExposure *exp; //!< Exposure data 111 } psOTADescription; 112 113 /** Constructor */ 114 psOTADescription * 115 psOTADescriptionAlloc(void); 116 117 /** Destructor. */ 118 void 119 psOTADescriptionFree(psOTADescription *restrict myOTA //!< OTA description to destroy 120 ); 121 122 /***********************************************************************************************************/ 123 124 /** Astrometric solution for an OTA. 125 * There are four coordinate frames that we need to worry about: 126 * 1. Chip frame: chip# plus x,y in pixels 127 * 2. Focal plane frame: X,Y in microns 128 * 3. Tangent plane: xi,eta in arcsec from the telescope boresight. 129 * 4. Sky frame: RA,Dec 130 * 131 * 1 <--> 2: OTA description (parent of this struct) specifies how the chips are mounted on the focal plane. 132 * 2 <--> 3: The astrometric solution corrects for distortions in the optics so we can go from what the 133 * telescope sees on the focal plane to what it really should be like (i.e. the tangent plane). 134 * 3 <--> 4: SLALib converts between the tangent plane and the celestial sphere using a set of numbers one 135 * must calculate for each tangent point. 136 * 137 * Coordinate frames 2 and 3 are generally hidden from the user because all they care about is going between 138 * frames 1 and 4. 139 */ 140 typedef struct { 141 /* Focal plane to and from tangent plane */ 142 psDPolynomial4D *restrict tpToFPX, *restrict tpToFPY; //!< General astrometric solution for tangent plane 143 //!< to focal plane 144 psDPolynomial4D *restrict fpToTPXi, *restrict fpToTPEta; //!< General astrometric solution for focal plane 145 //!< to tangent plane 146 psMatrix *pattern; //!< Fixed pattern distortions for focal plane to tangent plane (simply 147 //!< * -1 for the reverse); MAY NEED TO BE REVISED UPON IMPLEMENTATION 148 /* Tangent plane to and from the celestial sphere */ 149 psDoubleArray *restrict tp; //!< Data needed to convert from the sky to the tangent plane and back; 150 //!< produced by and used by SLALib (a.k.a. "Wallace's Grommit") 151 psColourRef colorRef; //!< Colour reference 152 /* Characterisation of the solution */ 153 float rmsX, rmsY; //!< Dispersion in astrometric solution 154 float chi2; //!< chi^2 of astrometric solution 155 } psOTAAstrom; 156 157 /** Constructor */ 158 psOTAAstrom * 159 psOTAAstromAlloc(const psExposure *exp //!< Telescope pointing, used to initialise the tp data. 160 ); 161 162 /** Destructor */ 163 void 164 psOTAAstromFree(psOTAAstrom *restrict myAstrom //!< Object to destroy 165 ); 166 167 /***********************************************************************************************************/ 168 169 /* Calculating and applying astrometric solutions */ 170 171 /** Convert (RA,Dec) to (cell#,x,y) */ 172 psOTAPos * 173 psSkyToOTA(const psSkyPos *restrict position, //!< Position on the sky 174 const psOTADescription *restrict ota //!< OTA details 175 ); 176 177 /** Convert (cell#,x,y) to (RA,Dec) */ 178 psSkyPos * 179 psOTAToSky(const psOTAPos *restrict position, //!< Position on the detector 180 const psOTADescription *restrict ota //!< OTA details 181 ); 182 183 /** Fit astrometric solution to list of (chip#,x,y) and (RA,Dec) */ 184 int 185 psFitAstrom(psOTADescription *restrict ota, //!< Initial guess for coefficients 186 const psOTAPosArray *restrict detector, //!< Positions on OTA (chip#,x,y) 187 const psSkyPosArray *restrict sky, //!< Positions on the sky (RA,Dec) 188 const psExposure *exp //!< Telescope pointing information, for airmass, parallactic angle 189 //!< which may help set the astrometric solution 190 ); 191 192 /***********************************************************************************************************/ 193 194 /* Functions needed for astrometry, and will likely be useful elsewhere */ 195 196 /** Get the airmass for a given position and sidereal time */ 197 float 198 psGetAirmass(const psSkyPos *restrict position, //!< Position on the sky 199 double siderealTime //!< Sidereal time 200 ); 201 202 /** Get the parallactic angle for a given position and sidereal time */ 203 float 204 psGetParallactic(const psSkyPos *restrict position, //!< Position on the sky 205 double siderealTime //!< Sidereal time 206 ); 207 208 /** Estimate atmospheric refraction, along the parallactic */ 209 float 210 psGetRefraction(float colour, //!< Colour of object 211 psColourRef colourRef, //!< Colour reference 212 psExposure *exp //!< Telescope pointing information, for airmass, temp and pressure 213 ); 214 215 /***********************************************************************************************************/ 224 ); 216 225 217 226 #endif
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