This note describes the IPP video cell photometry pipeline or "VP stage".
VP Run
vpRun is the table in the IPP database that is used to manage video cell photometry (VP) processing. When a run is processed all OTAs that contain video cells are processed. A new IPP tool program vptool was written to manage the database operations. Exposures are selected for processing using the command "vptool -definebyquery". The selectors are the same as used for chip processing so a wide range of options is available.
Usage: vptool -definebyquery [<options>] -definebyquery: -exp_id search by exp_id -exp_name search by exp_name -inst search for camera -telescope search for telescope -dateobs_begin search for exposures by time (>=) -dateobs_end search for exposures by time (<=) -exp_tag search by exp_tag -exp_type search by exp_type -filelevel search by filelevel -filter search for filter -airmass_min search by min airmass -airmass_max search by max airmass -ra_min search by min RA (degrees) -ra_max search by max RA (degrees) -decl_min search by min DEC (degrees) -decl_max search by max DEC (degrees) -exp_time_min search by min exposure time -exp_time_max search by max exposure time -sat_pixel_frac_min search by min fraction of saturated pixels -sat_pixel_frac_max search by max fraction of saturated pixels -bg_min search by min background -bg_max search by max background -bg_stdev_min search by min background standard deviation -bg_stdev_max search by max background standard deviation -bg_mean_stdev_min search by min background mean standard deviation (across imfiles) -bg_mean_stdev_max search by max background mean standard deviation (across imfiles) -alt_min search by min altitude -alt_max search by max altitude -az_min search by min azimuth -az_max search by max azimuth -ccd_temp_min search by min ccd tempature -ccd_temp_max search by max ccd tempature -posang_min search by min rotator position angle -posang_max search by max rotator position angle -sun_angle_min search by min solar angle -sun_angle_max search by max solar angle -object search by exposure object -comment search by comment field (LIKE comparison) -obs_mode search by observation mode -label search by newExp label (LIKE comparison) -set_label define label -set_data_group define data group -set_workdir define workdir (required) -set_note define note -set_dest_id define destination -pretend do not actually modify the database -unique only queue exposures that have no previous vpRun -simple use the simple output format
videophot_process.pl
The ippScript videophot_process.pl processes an entire vpRun. That is all OTAS are processed by a single job. This may be contrasted with chip processing where each OTA is processed separately. Since each video cell only takes a few seconds to process this is a reasonable choice.
The actual processing is performed by the program psvideophot. The output for each video cell is a FITS table (file extension vpt).
A second fits file is created which contains the original video cell data that has been extracted from the raw data. TODO: we should make creation of this file optional since it takes up ~4MB per cell (3pi)
vpt table
Each row in the vpt table contains the data for a frame. The data in the columns have 2 sources:
- The video_table extension created by the GPC1 camera software
- The results of the psvideophot analysis. These columns have names that begin with vp_
FITS table description (from header) TODO: do a proper table. TTYPE1 = 'frame_start_time' / label for field 1 TFORM1 = '1D ' / data format of field: 8-byte DOUBLE TTYPE2 = 'frame_complete_time' / label for field 2 TFORM2 = '1D ' / data format of field: 8-byte DOUBLE TTYPE3 = 'centroid_x' / label for field 3 TFORM3 = '1D ' / data format of field: 8-byte DOUBLE TTYPE4 = 'centroid_y' / label for field 4 TFORM4 = '1D ' / data format of field: 8-byte DOUBLE TTYPE5 = 'fwhm ' / label for field 5 TFORM5 = '1D ' / data format of field: 8-byte DOUBLE TTYPE6 = 'fwhm_x ' / label for field 6 TFORM6 = '1D ' / data format of field: 8-byte DOUBLE TTYPE7 = 'fwhm_y ' / label for field 7 TFORM7 = '1D ' / data format of field: 8-byte DOUBLE TTYPE8 = 'sky ' / label for field 8 TFORM8 = '1D ' / data format of field: 8-byte DOUBLE TTYPE9 = 'flux ' / label for field 9 TFORM9 = '1D ' / data format of field: 8-byte DOUBLE TTYPE10 = 'snr ' / label for field 10 TFORM10 = '1D ' / data format of field: 8-byte DOUBLE TTYPE11 = 'rowpre ' / label for field 11 TFORM11 = '1J ' / data format of field: 4-byte INTEGER TTYPE12 = 'cnpix1 ' / label for field 12 TFORM12 = '1J ' / data format of field: 4-byte INTEGER TTYPE13 = 'cnpix2 ' / label for field 13 TFORM13 = '1J ' / data format of field: 4-byte INTEGER TTYPE14 = 'vp_flux ' / label for field 14 TFORM14 = '1E ' / data format of field: 4-byte REAL TTYPE15 = 'vp_median' / label for field 15 TFORM15 = '1E ' / data format of field: 4-byte REAL TTYPE16 = 'vp_stddev' / label for field 16 TFORM16 = '1E ' / data format of field: 4-byte REAL TTYPE17 = 'vp_sum ' / label for field 17 TFORM17 = '1E ' / data format of field: 4-byte REAL TTYPE18 = 'vp_x ' / label for field 18 TFORM18 = '1E ' / data format of field: 4-byte REAL TTYPE19 = 'vp_y ' / label for field 19 TFORM19 = '1E ' / data format of field: 4-byte REAL
Results Data Store
When a run is queued it may optionally be assigned a data store product where results filesets will be posted. See for example http://datastore.ipp.ifa.hawaii.edu/ps1-vp/o5769g0314o.369032.vp.1
