LINEAR-POLARIZATION AND THE EFFECTS OF METAL REFLECTORS USED TO REDIRECT THE BEAM IN MICROWAVE RADIOMETERS

Problems concerning the response of microwave radiometers to the polar ization of incident radiation are examined. Particular attention is gi ven to their consequences in experiments measuring the intensity aniso tropy of the cosmic background radiation. Considered in detail are ins trumental configurations in which metal reflectors are used to redirec t the antenna beam. Some effects introduced by such reflectors are cal culated and modelled for different values of some relevant parameters, in order to evaluate their contribution to instrumental errors. The a nalysis of a real experiment is then considered. It is shown that such mechanisms, if ignored, can seriously affect the measurements.