El. Wright et al., PRODUCING MEGAPIXEL COSMIC MICROWAVE BACKGROUND MAPS FROM DIFFERENTIAL RADIOMETER DATA, The Astrophysical journal, 458(2), 1996, pp. 53
A major goal of cosmology is to obtain sensitive, high-resolution maps
of the cosmic microwave background anisotropy. Such maps, as would be
produced by the recently proposed Microwave Anisotropy Probe (MAP), w
ill contain a wealth of primary information about conditions in the ea
rly universe. To mitigate Systematic effects when observing the microw
ave background, it is desirable for the raw data to be collected in di
fferential form: as a set of temperature differences between points in
the sky. However, the production of large (megapixel) maps from a set
of temperature differences is a potentially severe computational chal
lenge. We present a new technique for producing maps from differential
radiometer data that has a computational cost that grows in the slowe
st possible way with increasing angular resolution and number of map p
ixels. The required CPU time is proportional to the number of differen
tial data points, and the required random-access memory is proportiona
l to the number of map pixels. We test our technique, and demonstrate
its feasibility, by simulating 1 yr of a spaceborne anisotropy mission
.