Index: trunk/doc/pslib/psLibSDRS.tex =================================================================== --- trunk/doc/pslib/psLibSDRS.tex (revision 256) +++ trunk/doc/pslib/psLibSDRS.tex (revision 271) @@ -676,4 +676,5 @@ \subsubsection{Coordinate frames} +\label{sec:coordinateFrames} There are five coordinate frames that we need to worry about for the @@ -743,5 +744,10 @@ first-order 2D polynomials, simply specifying a translation, rotation and magnification; hence they are easily inverted, and there is no -need to add reverse transformations. +need to add reverse transformations. We also add an additional +transformation, which is intended to provide a ``quick and dirty'' +transform from the cell coordinates to the sky; this transformation +not guaranteed to be as precise as the ``standard'' transformation of +Cell $\rightarrow$ Chip $\rightarrow$ Focal Plane $\rightarrow$ +Tangent Plane $\rightarrow$ Sky, but will be faster. \begin{verbatim} @@ -756,4 +762,5 @@ psCoordXform *cellToChip; ///< Transformations from cell coordinates to chip coordinates psCoordXform *cellToFPA; ///< Transformations from cell coordinates to FPA coordinates + psCoordXform *cellToSky; ///< Quick and Dirty transformations from cell coordinates to sky struct psChip *parentChip; ///< chip which contains this cell @@ -892,24 +899,307 @@ The fixed pattern is a correction to the general astrometric solution formed by summing the residuals from many observations. The intent is -to correct for higher-order distortions in the camera system - - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +to correct for higher-order distortions in the camera system on a +coarse grid (larger than individual pixels, but smaller than a single +cell). Hence, in addition to the offsets, we need to specify the size +and scale of the grid in $x$ and $y$, as well as the origin of the +grid. + +\begin{verbatim} +/** The fixed pattern residual offsets. These are specified via a coarse grid of x and y offsets. */ +typedef struct { + int nX, nY; //!< Number of elements in x and y + double x0, y0; //!< Position of the lower-left corner of the grid on the focal plane + double xScale, yScale; //!< Scale of the grid + double **x, **y; //!< The grid of offsets in x and y +} psFixedPattern; +\end{verbatim} + + +\subsubsection{Constructors and Destructors} + +Each of the above structures needs an appropriate constructor and +destructor. Other than \code{psExposure}, which contains significant +non-pointer types, the constructors should not take any arguments, and +the destructors should only take the structure to be destroyed. +The constructor for \code{psExposure} is specified below. + +\begin{verbatim} +/** Constructor */ +psExposure * +psExposureAlloc(double ra, double dec, //!< Telescope boresight + double ha, //!< Hour angle + double zd, //!< Zenith distance + double az, //!< Azimuth + double lst, //!< Local Sidereal Time + float mjd, //!< MJD + float rotAngle, //!< Rotator position angle + float temp, //!< Temperature + float pressure, //!< Pressure + float humidity, //!< Relative humidity + float exptime //!< Exposure time + ); +\end{verbatim} + + +\subsubsection{Finding} + +We require functions to return the structure containing given coordinates. +For example, we want the chip that corresponds to the focal plane coordinates +$(p,q) = (-1.234,+5.678)$. + + +\begin{verbatim} +/** returns Chip in FPA which contains the given FPA coordinate */ +psChip * +psChipInFPA (psFPA *fpa, ///< FPA description + psCoord *coord ///< coordinate in FPA + ); +\end{verbatim} + +\begin{verbatim} +/** returns Cell in Chip which contains the given chip coordinate */ +psCell * +psCellInChip (psChip *chip, ///< chip description + psCoord *coord ///< coordinate in chip + ); +\end{verbatim} + +Usually we will want to go directly from the FPA to the Cell, so we +also specify the following function, which performs the above two +functions in order. + +\begin{verbatim} +/** Return the cell in FPA which contains the given FPA coordinates */ +psCell * +psCellInFPA(psCell *out, //!< Cell to return, or NULL + psFPA *fpa, //!< FPA description + psCoord *coord //!< Coordinate in FPA + ); +\end{verbatim} + + + +\subsubsection{Conversion Functions} + +We require functions to convert between the various coordinate frames +(Section~\ref{sec:coordinateFrames}). The heirarchy of the coordinate +frames and the transformations between each are shown in +Figure~\ref{fig:coco}. The functions that employ the transformations +are shown in Figure~\ref{fig:cocoFunc}. In addition to +transformations between each adjoining coordinate frame in the +heirarchy, we also require higher-level functions to convert between +the Cell and Sky coordinate frames; these will simply perform the +intermediate steps. + +\begin{figure} +\psfig{file=coordinateFrames.ps,width=9in,angle=-90} +\caption{The coordinate systems in the \PS{} IPP, and the relation +between each by transformations contained in the appropriate +structures.} +\label{fig:coco} +\end{figure} + +\begin{figure} +\psfig{file=coordinateConv.ps,width=9in,angle=-90} +\caption{Conversion between coordinate systems by PSLib.} +\label{fig:cocoFunc} +\end{figure} + +The function prototypes are: + +\begin{verbatim} +/** returns Chip in FPA which contains the given FPA coordinate */ +psChip * +psChipInFPA (psChip *out, //!< Chip to return, or NULL + psFPA *fpa, ///< FPA description + psCoord *coord ///< coordinate in FPA + ); +\end{verbatim} + +\begin{verbatim} +/** returns Cell in Chip which contains the given chip coordinate */ +psCell * +psCellInChip(psCell *out, //!< Cell to return, or NULL + psChip *chip, ///< chip description + psCoord *coord ///< coordinate in chip + ); +\end{verbatim} + +\begin{verbatim} +/** Return the cell in FPA which contains the given FPA coordinates */ +psCell * +psCellInFPA(psCell *out, //!< Cell to return, or NULL + psFPA *fpa, //!< FPA description + psCoord *coord //!< Coordinate in FPA + ); +\end{verbatim} + +\begin{verbatim} +/** Convert (RA,Dec) to cell and cell coordinates */ +psCoord * +psCoordSkyToCell(psCoord *out, //!< Coordinates to return, or NULL + psCell *cell, //!< Cell to return + const psFPA *fpa //!< FPA description + ); +\end{verbatim} + +\begin{verbatim} +/** Convert cell and cell coordinate to (RA,Dec) */ +psCoord * +psCoordCellToSky(psCoord *out, //!< Coordinates to return, or NULL + const psCell *cell, //!< Cell to get coordinates for + psCoord *coord //!< cell coordinates to transform + ); +\end{verbatim} + +\begin{verbatim} +/** Quick and dirty cell to (RA,Dec) --- employs cellToSky transformation */ +psCoord * +psCoordCellToSkyQuick(psCoord *out, //!< Coordinates to return, or NULL + const psCell *cell, //!< Cell description + psCoord *coord //!< cell coordinates to transform + ); +\end{verbatim} + +\begin{verbatim} +/** Convert (RA,Dec) to tangent plane coords */ +psCoord * +psCoordSkyToTP(psCoord *out, //!< Coordinates to return, or NULL + psexposure *exp, //!< Exposure description + psCoord *coord //!< input Sky coordinate + ); +\end{verbatim} + +\begin{verbatim} +/** Convert tangent plane coords to focal plane coordinates */ +psCoord * +psCoordTPtoFPA(psCoord *out, //!< Coordinates to return, or NULL + const psFPA *fpa, //!< FPA description + psCoord *coord //!< input TP coordinate + ); +\end{verbatim} + +\begin{verbatim} +/** converts the specified FPA coord to the coord on the given Chip */ +psCoord * +psCoordFPAtoChip (psCoord *out, //!< Coordinates to return, or NULL + psFPA *fpa, ///< FPA description + psChip *chip, ///< Chip of interest + psCoord *coord ///< input FPA coordinate + ); +\end{verbatim} + +\begin{verbatim} +/** converts the specified Chip coord to the coord on the given Cell */ +psCoord * +psCoordChiptoCell (psCoord *out, //!< Coordinates to return, or NULL + psChip *chip, ///< Chip description + psCell *cell, ///< Cell of interest + psCoord *coord ///< input Chip coordinate + ); + +\begin{verbatim} +/** converts the specified Cell coord to the coord on the parent Chip */ +psCoord * +psCoordCelltoChip (psCoord *out, //!< Coordinates to return, or NULL + psCell *cell, ///< Cell description + psCoord *coord ///< input Cell coordinate + ); +\end{verbatim} + +\begin{verbatim} +/** converts the specified Chip coord to the coord on the parent FPA */ +psCoord * +psCoordChiptoFPA (psCoord *out, //!< Coordinates to return, or NULL + psChip *chip, ///< Chip description + psCoord *coord ///< input Chip coordinate + ); +\end{verbatim} + +\begin{verbatim} +/** Convert focal plane coords to tangent plane coordinates */ +psCoord * +psCoordFPAToTP(psCoord *out, //!< Coordinates to return, or NULL + psFPA *fpa, //!< FPA description + psCoord *coord //!< input FPA coordinate + ); +\end{verbatim} + +\begin{verbatim} +/** Convert tangent plane coords to (RA,Dec) */ +psCoord * +psCoordTPtoSky(psCoord *out, //!< Coordinates to return, or NULL + psExposure *exp, //!< Exposure description + psCoord *coord //!< input TP coordinate + ); +\end{verbatim} + +\begin{verbatim} +/** Convert Cell coords to FPA coordinates */ +psCoord * +psCoordCellToFPA(psCoord *out, //!< Coordinates to return, or NULL + psCell *cell, //!< Cell description + psCoord *coord //!< Input cell coordinates + ); +\end{verbatim} + +\subsubsection{Additional functions} + +We require additional functions to perform general functions which +will be useful for astrometry. Given coordinates on the sky, we +need to get the airmass, the parallactic angle, and an estimate of +the atmospheric refraction. + +\begin{verbatim} +/** Get the airmass for a given position and sidereal time */ +float +psGetAirmass(const psCoord *coord, //!< Position on the sky + double siderealTime, //!< Sidereal time + float height //!< Height above sea level + ); +\end{verbatim} + +\begin{verbatim} +/** Get the parallactic angle for a given position and sidereal time */ +float +psGetParallactic(const psCoord *coord, //!< Position on the sky + double siderealTime //!< Sidereal time + ); +\end{verbatim} + +\begin{verbatim} +/** Estimate atmospheric refraction, along the parallactic */ +float +psGetRefraction(float colour, //!< Colour of object + psPhotSystem colorPlus, ///< Colour reference + psPhotSystem colorMinus, ///< Colour reference + const psExposure *exp //!< Telescope pointing information, for airmass, temp and pressure + ); +\end{verbatim} + + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \subsection{Dates and times} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \subsection{Image handling} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +Gene + \subsection{Metadata} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +Gene + \subsection{Detector and sky positions} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \subsection{Astronomical objects} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \subsection{Photometry} - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +Gene + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \bibliographystyle{plain} \bibliography{panstarrs}