=head1 NAME imcore_list - list driven photometry package =head1 SYNOPSIS B I I I I I =head1 DESCRIPTION B performs aperture photometry on the FITS image I, optionally using a confidence map I. If no confidence map is to be used, I should be specified as C. The list of coordinates to drive the photometry is taken from the catalogue specified in I subject to one of several options specified in I. The catalogue may be given either as a FITS binary table in standard CASU format, or as an ascii RA,Dec list. The output is a FITS binary table catalogue, in B the same order as the input catalogue, in standard CASU catalogue format. The name of the output catalogue is derived from the I rootname and will be of the generic form I. Pre-existing catalogue files with this name will be automatically clobbered. In addition to the photometry, for compatibliy with normal CASU catalogues and for more general purpose use, the standard CASU parameter set for position and shape information is also derived, but is only based on the flux distribution in the default aperture specified on the command line. Repeat runs using different Is will generate identically ordered catalogues which can, for example, form the basis for matched lists of derived photometry for all processed files. Example uses would be for doing lightcurve analysis for temporal variablity studies or for matched multicolour aperture photometry analysis. Single or multi-extension input FITS images may be processed. If the source catalogue is a FITS binary table the number of extensions must match those of the input image. If the target position is close to the edge of the detector (within the aperture radius) or not on the detector, zero flux is returned. Positions are mapped using either WCS information or using an X-Y transformation matrix specified in I. The latter option being more suited to accurate temporal lightcurve analysis of multiple repeat observations of the same field. For each extension processed, a regions file for the DS9 image display tool is produced (these can be loaded from C in the C menu), containing commands to plot an ellipse (default circular aperture in this case) for each of the sources in the input catalogue list. These files are named by appending F<_n_list.ell> to the filename of the input image (after removing any F<.fit> extension), where I is the number of the corresponding extension in the output catalogue file (numbered from 1). Background analysis and estimation is performed in the same manner as used for the CASU standard catalogue generation package and is used to track and effectively remove background variations on the scale of 64 pixels (default). For each valid target position a fixed aperture of radius I is overlaid on the image and the background-corrected flux summed over the region. Proportionating the flux across boundary pixels compensates for pixel edge effects and follows essentially the same procedure used in the standard CASU catalogue generator. The remaining flux parameters are estimated in the same way and position, shape parameters are derived as indicated above. =head1 OPTIONS The following command-line arguments are supported: =over =item I Standard FITS images either single or multiextension are supported. =item I Uses the confidence map from I in the analysis. If a filename of I is specified no confidence map is used in the analysis. =item I This file can either be a standard CASU FITS binary catalogue table or an external ascii list of Ra,Dec (J2000 only), with one entry per line in sexagesimal format (eg. HH MM SS DD MM SS ..........). (A later additional supported format will be to allow object positions to be taken from a standard CASU merge file as output by I.) =item I There are 3 options for this argument: I implies take the binary catalogue table WCS to generate positions; I implies that the file I is an ascii RA,Dec list and the positions are to be taken directly from it; I alternatively an X-Y transformation matrix may be provided to directly map the target list using a more accurate pixel coordinate transformation (this can be generated automatically using I). =item I The radius of the aperture to be used for the photometry. Each object in the list is currently processed independently if it derives from an external RA,Dec list, or is processed in groups in the original blend pattern embedded in the binary catalogue file. =back =head1 EXAMPLES Build up a series of light curve anaylsis files by repeatedly running on a time series of images using the same master list, use fixed default apertures of radius 3 pixels, and use pixel coordinate mapping. imcore_list image001.fit noconf master_cat.fits image001.trans 3.0 imcore_list image002.fit noconf master_cat.fits image002.trans 3.0 ................................................................... imcore_list image320.fit noconf master_cat.fits image320.trans 3.0 Use an Ra,Dec list derived from eg. radio sources to lay down fixed size apertures and estimate the flux at the expected positions of the radio sources. imcore_list r12345.fit I_conf.fits radiolist use=radeclist 5.0 Analyse the J and H images using the K catalogue detection file imcore_list J_today.fit J_conf.fits K_today_cat.fits use=wcs 3.5 imcore_list H_today.fit H_conf.fits K_today_cat.fits use=wcs 3.5 =head1 AUTHOR Mike Irwin (mike@ast.cam.ac.uk) =cut