摘要 |
PURPOSE:To simplify the circuit constitution by performing secant correction, coordinate conversion, and phase difference correction collectively in one place in an azimuth elevation mount four-converging reflective mirror beam feeding Cassegrain antenna. CONSTITUTION:Azimuth and elevation angle error signals are read through error signal input circuits 3 and 4, and an azimuth thetaAZ and an actual elevation angle thetaEL of the antenna are read from input circuits 5 and 6, and they are operated by a microprocessor 9. Azimuth and elevation angle error signals which are detected with new rotated azimuth-elevation coordinates are subjected to coordinate rotation by DELTAtheta=thetaAZ+thetaEL to convert them to azimuth and elevation angle error signals on reference azimuth-elevation coordinates, and cosecthetaEL is multiplied by the azimuth angle error signal to perform secant correction. Coordinate rotation is performed by DELTAthetaS, which is a phase difference between the sum signal and the error signal generated by route switching of a low noise amplifier or frequency switching of a beacon signal, thus compensating the phase error. |