|Primary Goal: The QMAP experiment was
a balloon-borne CMB telescope designed to map anisotropy on degree scales
and to measure the angular power spectrum covering the range 40 < l
Optics: Four cooled corrugated feeds under-illuminate a fixed off-axis parabolic mirror of 0.85m diameter. The mirror in turn under-illuminates a large chopping flat (chopper). The chopper is closest to the sky so that the illumination on the parabola is stationary.
Sky Coverage: 527 square degrees in multiply interlocking pattern allowing for internal checks leading to a true map