The X-Y Antenna Mount for Data Acquisition from Satellites

Abstract

Earth-orbiting satellite programs demand optimum performance from automatic tracking antenna systems. Certain criteria such as maximum drive shaft rates and best satellite data transmission conditions are considered in the design of the antenna mount. This paper describes the advantages of using an X-Y antenna mount for performing data acquisition and satellite tracking functions. Maximum shaft rates of two-axis mounts are compared under similar satellite pass conditions, and the relative advantages of using an X-Y mount are discussed. A discussion of several of the general design considerations of the servo-control system is presented, and a discussion relating the error constants to the output rates is given. A few salient features describing the advantages of the X-Y mount, from the servo drive system designer's viewpoint, are also presented. The paper concludes with a brief description of NASA's 85-ft parabolic X-Y antenna located at the Data Acquisition Facility at Gilmore Creek, Fairbanks, Alaska.