| POLAR is a Cosmic Microwave Background (CMB) experiment designed
to look for polarization in the CMB at large angular scales. It is a single-pixel,
correlation polarimeter that operated in the Ka frequency band (26-36 GHz).
It collected approximately 750 hours of data from its observation site in
Pine Bluff, Wisconsin, from March 10 through May 29, 2000. It has since
been decommissioned, and its radiometer has been integrated into the
COMPASS Telescope. Analysis of the single season of data set an
upper limit of 10 µK on both E- and B- mode polarization on angular
scales greater than 7°.