WPHot Multi-Epoch Output File Description (Mar 22, 2013) [pht07 WSDC D-I197] Interface Name: WPHot Interface Type of Interface: program i/o Written By: WISE Photometry System (WPHot) __________ C. Grillmair Read By: Description: The multi-epoch (or MEP) tables contain, for each source, wpro photometric measurements for every frame on which a source appeared. These individual measurements, along with associated Julian dates and frame IDs, are collected in large arrays by WPHotpm, and are then passed to subroutine writeTABLE for output to the mep tables. To speed I/O and minimize storage requirements, the mep tables are written out as binary files. A WPHotpm namelist parameter (max_mep_lines) specifies the maximum number of lines to write to each file. When this value is exceeded for a given source in a given file, the remaining epochal entries for that source are written to the file, whereupon the file is closed, a new mep file is opened, and sources are written to the new file until max_mep_lines is once again exceeded. The root file name is specified on the WPHotpm command line with "-meproot filename". "filename" is assumed to be of the form xxxxx000.mep, with the last three characters before the '.' specifying a file number. This number is incremented by one every time max_mep_lines is exceeded and a new mep file is opened. Dumpmep, a utility written by T. Conrow, is available to dump the contents of mep tables into ascii files, selecting desired columns or rows, converting NaNs to Nulls, etc. ______________________________________________________________________________________________ Output file description: Mep files are opened in writeTABLE using the FORTRAN statement: open(unit=munit,file=meproot,status='unknown', form='unformatted', access='SEQUENTIAL', recl=33) For unformatted output, the Intel fortran compiler interprets the recl to be in units of 4 bytes, so the mep table record lengths are 132 bytes, which is the minimum required to contain all needed columns. Each mep file contains a single, integer*4 binary number in the first 4 bytes of the file which specifies the total number of sources (*not* lines) written to the file. For each new source, a single-line binary header is written out, followed by N rows with individual frame photometry for the N frames on which the source appeared. ______________________________________________________________________________________________ Specification of output variables: Photometry for each source is prefaced by a single-line binary header record which includes the following: bytes Name Description Units Type ----- -------- ------------------------------------------------ ----- ---- 1-24 source_id_mf WPHot-assigned source ID (same as in mdex file) -- char 25-26 src_mf sequential number of source in tile -- int 27-34 ra right ascension (J2000) deg R*8 35-42 dec declination (J2000) deg R*8 43-44 n_ep number of frames following for this source -- int The variable names are those used for dumpmep column selection. The source_id, ra, and dec are identical to those written to the mdex files. The subsequent n_ep records give the individual frame photometry. Upper limits are computed as for mdex files, and their uncertainties are given as 9.99 mag. Unmeasured or invalid measurements (e.g. w?sigflux < 0.) are assigned NaN values. Once again, variable names are those used by dumpmep. bytes Name Description Units Type ----- ---- ------------------------------------------------ ----- ---- 1-4 w1x_ep x-coordinate, band 1 pix R*4 5-8 w1y_ep y-coordinate, band 1 pix R*4 9-12 w1mpro_ep wpro magnitude, band 1 mag R*4 13-16 w1sigmpro_ep wpro magnitude uncertainty band 1 mag R*4 17-20 w1rchi2_ep wpro chi^2, band 1 -- R*4 21-24 w1flux_ep wpro flux, band 1 dn R*4 25-28 w1sigflux_ep wpro flux uncertainty, band 1 dn R*4 29-32 w2x_ep x-coordinate, band 2 pix R*4 33-36 w2y_ep y-coordinate, band 2 pix R*4 37-40 w2mpro_ep wpro magnitude, band 2 mag R*4 41-44 w2sigmpro_ep wpro magnitude uncertainty band 2 mag R*4 45-48 w2rchi2_ep wpro chi^2, band 2 -- R*4 49-52 w2flux_ep wpro flux, band 2 dn R*4 53-56 w2sigflux_ep wpro flux uncertainty, band 2 dn R*4 57-60 w3x_ep x-coordinate, band 3 pix R*4 61-64 w3y_ep y-coordinate, band 3 pix R*4 65-68 w3mpro_ep wpro magnitude, band 3 mag R*4 69-72 w3sigmpro_ep wpro magnitude uncertainty band 3 mag R*4 73-76 w3rchi2_ep wpro chi^2, band 3 -- R*4 77-80 w3flux_ep wpro flux, band 3 dn R*4 81-84 w3sigflux_ep wpro flux uncertainty, band 3 dn R*4 85-88 w4x_ep x-coordinate, band 4 pix R*4 89-92 w4y_ep y-coordinate, band 4 pix R*4 93-96 w4mpro_ep wpro magnitude, band 4 mag R*4 97-100 w4sigmpro_ep wpro magnitude uncertainty band 4 mag R*4 101-104 w4rchi2_ep wpro chi^2, band 4 -- R*4 105-108 w4flux_ep wpro flux, band 4 dn R*4 109-112 w4sigflux_ep wpro flux uncertainty, band 4 dn R*4 113-120 mjd Modified Julian Date day R*8 121-129 frame_id scan/frame ID -- char