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Timestamp:
Sep 27, 2005, 7:43:49 AM (21 years ago)
Author:
eugene
Message:

minor cleanups, web edits

File:
1 edited

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  • trunk/Ohana/doc/www/html/DVO/addstar.htm

    r4726 r5144  
     1<meta name=file  content=addstar>
     2<meta name=title content=addstar>
     3<meta name=page  content=addstar>
     4
     5<p>
     6This program takes a photometry file, with astrometry, provided by
     7earlier routines and incorporates the stellar measurements into the
     8photometry database.  This routine does NOT try to calibrate or check
     9the photometry, nor does it try to improve the coordinate
     10determinations or calculate chisquares for position or photometry -
     11those tasks are performed by other routines.
     12
     13<p>
     14Addstar starts by loading in the photometry file and converting the
     15pixel coordinates to sky coordinates using the astrometry information
     16in the header of the file.  It also gets the detection limits and
     17stores the image astrometry information.
     18
     19<p>
     20Next, addstar determines which of all the previous images overlaps
     21with this image and also which of the catalog regions overlaps with
     22this image.
     23
     24<p>
     25Addstar considers each catalog region in turn, and compares the
     26positions of stars in the catalog with stars in the image.  If a
     27catalog star is detected, a new measurement is added to the catalog.
     28If a catalog star is not detected, but is in the field of view of this
     29image, the detection limit for this image is added to the list of
     30measurements as an upper limit.  If the image contains a star which is
     31not already included in the catalog, the star is added to the catalog,
     32and all previous images are checked to see if they included this
     33location.  If so, upper limits are added to the list of measurements.
     34
     35<p>
     36To deal with blended images, we have taken the philosophy that all
     37measurements compatible with the coordinates of a given star should be
     38included in the list of measurements.  This assumes that programs or people
     39downstream will figure out which is the "correct" measurement.  To
     40this end, if a catalog star is consistent with multiple measurements,
     41they are all added to the catalog measurement and the measurements are
     42given a flag to say that there was blending in the catalog (ie, it is
     43probably the catalog star which is a blend).  If multiple catalog
     44stars are consistent with the same image star, that measurement is
     45added to each catalog star, and given a flag to say that there was
     46blending on the image.
     47
     48<p>
     49After all catalogs have been checked, updated, and written to disk,
     50the image is added to the database of images.
     51
     52<p>
     53see <a href=database.html> DVO database </a> for discussion of the
     54database storage format.   
     55
     56<hr>
     57
     58<h2> Usage </h2>
     59
     60<pre>
     61 addstar (filename)
     62 addstar -cat (catalog)
     63 addstar -ref (filename)
     64</pre>
     65
     66<p>
     67In the first form, addstar loads the photometry information for a
     68single image into the database.  The file must be in one of the Elixir
     69cmp/smp/smf formats, and must have been astrometrized (eg, with
     70gastro, gastro2, and/or mosastro).  The file must also be provided
     71with a valid photcode in the header (keyword PHOTCODE) or the photcode
     72must be supplied as an option to addstar (see below).  The photcode
     73must be listed in the photcode table (see config variable
     74PHOTCODE_FILE).  In the case that the image has been astrometrized
     75with mosastro (two-level mosaic astrometry), the corresponding mosaic
     76header unit must be supplied as an option (see below). 
     77
     78<p>
     79In the second form, addstar will load photometry from the specified
     80reference catalog, located in a known location, and will load it into
     81the database.  Allowed catalog names are: <tt> USNO, GSC, 2MASS,
     822MASS-ALLSKY, 2MASS-DR </tt>.  Note that USNO corresponds to the
     83USNO-A catalog, 2MASS corresponds to the 2MASS-ALLSKY catalog.  It is
     84necessary to have defined an appropriate photcode for the given
     85catalog.  The following photcodes are expected to exist:
     86
     87<table>
     88<tr><th> catalog </th><th> allowed photcodes         </th></tr>
     89<tr><td> GSC     </td><td> GSC_M                     </th></tr>
     90<tr><td> USNO    </td><td> USNO_RED, USNO_BLUE       </th></tr>
     91<tr><td> 2MASS*  </td><td> 2MASS_J, 2MASS_H, 2MASS_K </th></tr>
     92</table>
     93
     94When more than one photcode is allowed, one must be selected; there
     95are no defaults in that case. <em>It is advised that addstar -cat be
     96used with a restricted region of the sky; the default behavior will
     97load the reference catalog for the entire sky into the DB!</em>
     98
     99<p>
     100In the third form, addstar will load data from the specified ASCII
     101text file with a fixed format.  The file must contain lines with one
     102line per star.  The first four columns must contain the values RA,
     103DEC, Magnitude, Magnitude error.  The RA and DEC must be in J2000
     104decimal degrees.  Blank lines are allowed, and lines may be commented
     105with the hash sign (#).  The provided photometry must all be for a
     106single photcode, which must be provided as a command-line option.
     107
     108<h2> Additional Options </h2>
     109
     110<pre>
     111  -region ra ra dec dec           : only add data in specified region (-ref mode only)
     112  -p (photcode)                   : specify photcode (override header)
     113  -time (YYYY/MM/DD,HH:MM:SS)     : specify date/time (override header)
     114  -mosaic (filename)              : identify associated mosaic frame for chip image
     115  -fits                           : input file is FITS table, not TEXT table
     116  -existing-regions               : only add measurements to existing catalog files
     117  -only-match                     : only add measurements to existing objects
     118  -missed                         : skipped 'missed' entries
     119  -replace                        : replace time/photcode measurements (no duplication)
     120  -image                          : only insert image data
     121  -cal                            : perform zero-point calibration
     122  -skyprobe                       : specify skyprobe mode
     123  -2massquality                   : define 2MASS quality flags to keep
     124  -accept                         : accept bad astrometry from header
     125  -force                          : force read of database with inconsistent info
     126  -v                              : verbose mode
     127  -dump (mode)                    : output test data
     128  -help                           : print this list
     129  -h                              : print this list
     130</pre>
     131
     132
     133<h2> Elixir Configuration Data </h2>
     134
     135addstar uses the following Elixir configuration variables:
     136
     137<ul>
     138<li> EXPTIME-KEYWORD  : header keyword defining exposure time
     139<li> DATE-KEYWORD  : header keyword defining the date
     140<li> DATE-MODE  : mode for header date information: use a combination
     141of Ys, Ms, Ds to specify order.  If only 2 digits are specified for
     142the year, numbers greater than 50 are assumed in the 1900s, less than
     143in the 2000s.  eg YYYY/MM/DD
     144<li> UT-KEYWORD  : header keyword defining UT
     145<li> MJD-KEYWORD  : header keyword defining MJD
     146<li> JD-KEYWORD  : header keyword defining JD
     147<li> AIRMASS-KEYWORD
     148<li> CCDNUM-KEYWORD
     149<li> ST-KEYWORD
     150
     151<li> RADIUS : radius for matches; may have the value "header", in which
     152case the astrometric error listed in the header, along with
     153<tt>NSIGMA</tt> is used to define a match.  Otherwise, defines a
     154radius in arcseconds.
     155
     156<li> NSIGMA : number of astrometric error sigma to use for match
     157radius (see <tt>RADIUS</tt>).
     158
     159<li> XOVERSCAN : used to define valid pixels in the image. subtracted
     160from image NAXIS1 value to define image box.
     161
     162<li> YOVERSCAN : used to define valid pixels in the image. subtracted
     163from image NAXIS2 value to define image box.
     164
     165<li> ADDSTAR_XMIN : this value, and the following three, are used to
     166define a region on the image where the photometry is considered
     167reliable.  Stars outside this region are marked as having poor
     168measurements.
     169
     170<li> ADDSTAR_XMAX : see <tt>ADDSTAR_XMIN</tt>
     171<li> ADDSTAR_YMIN : see <tt>ADDSTAR_XMIN</tt>
     172<li> ADDSTAR_YMAX : see <tt>ADDSTAR_XMIN</tt>
     173
     174<li> MIN_SN_FSTAT : only include objects in the DB with S/N greater
     175than this value.
     176
     177<li> GSCDIR        : location of the HST Guide Star Catalog
     178<li> USNO_CDROM    : location of the USNO-A data
     179<li> 2MASS_DIR_AS  : location of the 2MASS allsky data
     180<li> 2MASS_DIR_DR2 : location of the 2MASS DR2 data
     181
     1822MASS, USNO, and GSC are all loaded from their idiosyncratic formats.
     183
     184<li> GSCFILE  : location of the GSC layout file (for GSC and ptolemy)
     185<li> CATDIR  : location of the ptolemy data
     186<li> IMAGE_CATALOG : location of the image database table
     187
     188<li> CATMODE : storage mode for the database.  may be one of RAW,
     189MEF, SPLIT, MYSQL.  SPLIT and MYSQL are currently unsupported.  This
     190defines the output format for new tables; the input format is auto-detected.
     191
     192<li> CATFORMAT : data format for the database.  may be one of LONEOS,
     193ELIXIR, PANSTARRS.
     194
     195<li> PHOTCODE_FILE : location of the photcode file describing the
     196photometry system of interest.
     197
     198<li> OBSERVATORY-LATITUDE : hard-wired observatory latitude.  used for
     199precision airmass for skyprobe.  <em> should be replaced with a more
     200sophisticated approach</em>
     201
     202<li> SUBPIX_DATAFILE : table for subpixel structure corrections (skyprobe)
     203
     204<li> IMAGE_CATALOG_TEMPLATE : deprecated, was used to supply a FITS
     205header template
     206<li> CATALOG_TEMPLATE : deprecated, was used to supply a FITS
     207header template
     208</ul>
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