Notes from Gene on test data distributed ~ Oct 2008

Each directory contains the output data products from the 'chip' and 'camera' stage analysis of the IPP. A few notes on what is in this directory:

The directory name:

*o4732g0168o : this is the exposure name given at the telescope: (o - data taken by OTIS; 4732 - truncated MJD; g - data taken with GPC; 0168 - sequence number; o - OBJECT (not b / BIAS, d / DARK, f / FLAT, etc). *34857 : this is an IPP unique exposure ID

Within the directory are files from the chip-level analysis with names starting with, where 'ch.2676' identifies the data with the chip analysis by the IPP unique chip-analysis ID (one per exposure) and XYij identifies the GPC1 ccd (i and j run from 0 to 7).

Also within the directory are files from the camera-level analysis, with names starting with; as before, the cm denotes 'camera-level analysis', and the 2174 is the IPP unique camera analysis ID.

For each chip, there are the following files: -- detrended FITS image binned 16x16 -- detrended FITS image binned 150x150 -- detrended FITS image -- mask image -- variance image (weight image) -- detected object table -- processing log -- low-resolution background model -- analysis configuration file -- processing statistics -- program trace messages

  • the images have had the mask applied and masked pixel values replaced from the background model (for cosmetic reasons only).
  • these detrend images have NOT been compressed, and are stored as 32bit floats, though for the survey data products, compression will be applied.
  • the weight and mask images are compressed using the method implemented by CFITSIO (version 3.09 and ds9 5.3 recommended)
  • the cmf file (detected objects) is not the final format; some modifications are being finalized. However, it is close to the final version.

For the camera-level data products, the b1 and b2 fits images are assembled into a full mosaic and converted to jpegs. In this example, the images are rotated 180 from their intended orientation; chip XY00 is in the upper left corner. No astrometry calibration has been applied, and the standard output smf data product was skipped.