NAME

 
TcsCatalog - class for accessing TCS catalogs

SYNOPSIS

 
#include "TcsCatalog.h"

class TcsCatalog : public AstroCatalog {
public:
    TcsCatalog(const CatalogInfoEntry* e);
    virtual ~TcsCatalog();

    static TcsCatalog* open(const char* name);

    int numCols();
    char** colNames();
    const char* colName(int col);
    int colIndex(const char* colName);
    int hasCol(const char* name);

    int getObject(const char* id, TcsCatalogObject& obj);

    int searchClosestStar(const WorldCoords& pos,
        double mag0, double mag1,
        TcsCatalogObject& obj);
};

DESCRIPTION

 
This class is a subclass of AstroCatalog specialized for accessing
GSC, PPM or similar catalogs for use by the TCS (Telescope Control
Software).  A TcsCatalog is like an AstroCatalog, except that it
assumes a catalog has fixed columns, such as those that are found in
the GSC or PPM catalogs.  This class restricts itself to these fixed
columns and ignores the rest.  Each row of a TcsCatalog can be
represented by a TcsCatalogObject. Any missing column values are set
to the appropriate null value (defined in TcsCatalogObject.h).

CATALOG SERVERS

 
This class uses the same catalog servers as the AstroCatalog class. Please
refer to AstroCatalog for details.

LOCAL CATALOGS

 
The format of local catalog files and query results that are stored in
files is the same here as in AstroCatalog, except that here the
column names are fixed. In addition, catalogs saved in TCS format
contain additional comments in the header indicating that the catalog
is a TCS catalog and with the meanings of the columns.

UNITS

 
Unless otherwise stated, the units for all radius values are in arcmin.
Floating point values for RA and DEC are always in degrees. The
default equinox is J2000.

QUERY PARAMETERS

 
Parameters for catalog searches are checked to make sure they are
valid and in the correct range. A radius value must be between 0.0 and
300.0 arcmin.  A magnitude may have any value. For ranges, such as min
and max radius and min and max magnitude, the order of the arguments
is not important, since they will be rearranged as needed. If both min
and max values are 0.0, they are ignored for that search. If you
really want to search for objects with "0.0" magnitude, specify a
range with small values that are not zero, for example, min/max mag =
(-0.0001, +0.0001).

PUBLIC METHODS

 
TcsCatalog(const CatalogInfoEntry* e)
        Constructor - create a TCS catalog class instance.  Note: the
        public interface normally uses TcsCatalog::open().  The
        argument represents the entry in the catalog config file for
        this catalog.

~TcsCatalog()
        Destructor - close catalog and free any resources.

open(const char* name)
        Open the named catalog and return a pointer to a new
        TcsCatalog (or derived class) object created for it or NULL if
        errors occur. If the given name is really the name of a file,
        it is opened as a local catalog and the pointer returned is of
        type TcsLocalCatalog, a subclass of TcsCatalog. If the file
        is not in the correct format, a NULL pointer is returned.

numCols()
        Return the number of columns in the catalog (fixed number).

colNames()
        Return an array of column names (this is always the same for
        TCS catalogs).

colName(int col)
        Return the name of the given column (fixed for TCS catalogs).

colIndex(const char* colName)
        Return the column index for the given column name (fixed for
        TCS catalogs).

hasCol(const char* name)
        Return true if the catalog contains the given column (fixed
        for TCS catalogs).

int getObject(const char* id, TcsCatalogObject& obj)
        This method is redefined in this class to get the object given
        by "id" in the catalog and return 0 if all is OK.  Note that
        the interface is changed here to use the TcsCatalogObject to
        hold the result rather than a QueryResult as in the parent
        class version.

        Arguments:

        id,             (in ) - object id in catalog.
        obj             (out) - object for row, if found.

int searchClosestStar(const WorldCoords& pos, double mag0, double mag1,
                      TcsCatalogObject& obj)
        This method is redefined in this class to search for the star
        closest to the given position, with the magnitude in the given
        range. Note that the interface is changed here to use the
        TcsCatalogObject to hold the result rather than a QueryResult
        as in the parent class version.

        Arguments:

        pos,            (in )  - center position in world coordinates
        mag0,           (in )  - min magnitude
        mag1,           (in )  - max magnitude
        obj             (out)  - object for row, if found

SEE ALSO

 
AstroCatalog, TcsCatalogObject(3C++), TcsQueryResult(3C++),
TcsLocalCatalog, tcscat(n)

 


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Last change: 07 May 99