The data made available through this page has been updated. The most recent version of this data may be accessed through /product/map/current/
I Maps (per frequency)
HEALPix, nested, res 9 (Nside=512)
0.23°- 0.93° (frequency dependent)
Five maps, one for each of the five frequency bandpasses observed by WMAP. These frequency maps are derived from the individual differencing assembly maps.
For each pixel in a frequency map, noise weighting is used to compute the average temperature from the individual differencing assembly map values. Since there is only one differencing assembly for the K and Ka bandpasses, the K and Ka frequency maps are identical to the K1 and Ka1 differencing assembly maps. The Q map is the noise-weighted result from combining Q1 and Q2, V is derived from V1 and V2, and W derives from W1, W2, W3 and W4.
The data provided in each frequency map consist of two fields for each pixel:
Pixel noise can be evaluated from N_obs via sigma = sigma_0/sqrt(N_obs), where sigma_0 for each frequency is listed in the following table:
More details can be found in: