Wilkinson Microwave Anisotropy Probe

Product Name
Time-Ordered Data (archive with attitude, etc.)


Three complete time-ordered data archives are supplied with the last WMAP data release; two contain calibrated data while the third contains uncalibrated (or raw) data. The uncalibrated archive contains all four radiometer channels for each observation. One calibrated archive has been coadded into two radiometer channels to reduce their size while the other contains all four radiometer channels.

This data are provided through a set of compressed tar files. Each tar file contains twenty files; each of these files contains one day of WMAP data written in five binary FITS tables. These tables contain:

Meta Data Position and attitude data for each record in the TOD file. The other tables are synchronized in time to this one through the use of indices contained in each table.
Science Data The science data.
Analog Instrument Housekeeping Data Physical measurements indicating the current state of the instrument.
Digital Instrument Housekeeping Data Digital instrument status and command information. Some physical measurements are included.
Line-of-Sight Vectors Twenty unit vectors describing the line of sight for each beam in spacecraft coordinates. Unlike the other tables, this one remains constant across files. Coupled with the position and attitude information in the Meta Data table, the pointing for each beam can be determined.

For a far more complete description of the time-ordered data and these files, see the WMAP Explanatory Supplement. A sample of each FITS header is available here. IDL routines to read this product are available from the WMAP Software page.

Additional Information

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A service of the HEASARC and of the Astrophysics Science Division at NASA/GSFC
Goddard Space Flight Center, National Aeronautics and Space Administration
HEASARC Director: Dr. Alan P. Smale
LAMBDA Director: Dr. Eric R. Switzer
NASA Official: Dr. Eric R. Switzer
Web Curator: Mr. Michael R. Greason