In-orbit satellite antenna measurements

With the trend in newer generations of spacecraft toward large number of complex antenna beams there is a need to perform the in-orbit testing (IOT) and measurements of spacecraft antenna patterns more rapidly than was previously required. This paper describes COMSAT Laboratories slew antenna measurements. The slew measurement is performed much faster and with much greater data point density than the conventional point-by-point antenna pattern measurement methods. The slew antenna measurement is performed at saturation and the saturation flux density and EIRP are measured at the test station while the satellite antenna is moved, resulting in a "cut" of antenna data as measured from the earth station(s) performing the measurements. Antenna "cut" data is then proecssed by COMSAT Laboratories' Antenna Coverage Program (ACP/sup TM/) into antenna contours.