Wilkinson Microwave Anisotropy Probe

The data made available through this page has been updated. The most recent version of this data may be accessed through /product/map/current/

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

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.

Changes

• 09/16/2009 - A documentation error was discovered in the uncalibrated time-ordered FITS files. The headers reported the data to be in units of millikelvin while it is actually stored in counts. The FITS headers were corrected to properly reflect the contents of the files.

Additional Information

• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Data Processing, Sky Maps, and Basic Results, G. Hinshaw, et.al. (2008)
• WMAP Five Year Explanatory Supplement

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