WMAP DR1 I Maps (Individual Differencing Assemblies)

The data made available through this page has been updated. The most recent version of this data may be accessed through https://lambda.gsfc.nasa.gov/product/wmap/current/

Iterative algorithms are used to create skymaps from the calibrated differential time-ordered WMAP data for each of the ten differencing assemblies. Each pixel in a map represents a sky temperature for the bandpass appropriate to the differencing assembly. The CMB dipole has been removed and the zero point of each map has been set using a Galactic csc |b| model (see Bennett et al. below).

The data provided in each map consist of two fields for each pixel:

• the thermodynamic temperature, in mK, and
• the effective number of observations, N_obs.

Pixel noise can be evaluated from N_obs via sigma = sigma_0/sqrt(N_obs), where sigma_0 for each differencing assembly is listed in the following table:

Differencing Assembly	K1	Ka1	Q1	Q2	V1	V2	W1	W2	W3	W4
sigma_0 (mK)	1.42366	1.44883	2.26677	2.15567	3.28789	2.93683	5.85196	6.53276	6.88032	6.72537

More details can be found in:

"First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations:
Data Processing and Systematic Errors Limits," Hinshaw, et al., 2003

"First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations:
Foreground Emission," Bennett, et al., 2003

"Producing Megapixel Cosmic Microwave Background Maps from Differential Radiometer Data," Wright, Hinshaw, and Bennett, ApJ Lett, 458, L53-L55, 1996

WMAP Explanatory Supplement