<?php include "@HTDOCS@/www-util/ippdata.page.php"; ?>

# PS1 Photometric Reference Ladder, Release 12.01

(up to [PS1 Data Release](/ippdata/index.php))

The PS1 Photometric Reference Ladder (Release 12.01) provides
reference PS1 photometry for 1-degree wide bands across the sky.
There are 24 rungs in RA (1 at each integer RA hour) and 4 rungs in
DEC (at -25, 0, +25, and +50 degrees).  In each band, a maximum of
~1000 objects per square degree are provided.  

The reference catalog data are provided in 2 formats: FITS tables and
Comma-Separated Values text files.  The latter may be easily loaded
into excel or certain database software.  

There are two sets of tables: ubercal and relphot.  The ubercal tables
only include objects for which measurements in all 5 filters were used
for the ubercal solution.  These data come from time periods which
have been judged as photometric and reprensent the most pristine
sample.  

The relphot tables include objects for which some (or even all) of the
filters have been calibrated via relative photometry using image
overlaps to connect them to images in the ubercal set.  Please take
care when using the relphot tables, as the relative photometry tie may
allow for substantial drift in certain patches in the sky (see Figure
6 in Magnier et al 2013).

* [Magnier et al, 2012 : Photometric Reference Ladder, Release 12.01 Paper (pdf)](../docs/photladder-1206.20130301.pdf)

@ Data Product             : none                       : plain : title : Comment
@ Ubercal FITS tables  : ubercal-fits : dir   : dir1  : NOTES
@ Ubercal CSV tables  : ubercal-csv : dir   : dir2  : NOTES
@ Relphot FITS tables  : relphot-fits : dir   : dir1  : NOTES
@ Relphot CSV tables  : relphot-csv : dir   : dir2  : NOTES

