design and implementation of a ground early warning receiver for monitoring signal of sar satellites

in this paper, a ground early warning receiver is introduced and explained for the reception and monitoring of signal from a space-borne synthetic aperture radar. this receiver can be used for various electronic warfare applications and implemented in two sectors of time parameter detector and frequency parameter detector. it can measure power, bandwidth, central frequency, pulse width, pulse repetition frequency, antenna pattern shape, and imaging duration time from the received signal. in section of frequency parameter detector, the narrow band sweeper heterodyne method is used that has not been applied previously. based on this receiver, we invented a new method for recognizing lfm signal from other pulse compression methods. also, in this paper, technique is demonstrated for identifying sar signals from other signal sources and estimation imaging parameters. moreover, a new method is described for calculating the power of the received signal on the ground, which does not require knowing transmitted power. at the end of this report, several cases of success in receiving signal from cosmo-skymed and fia-radar are listed and some of the obtained parameters from signal are compared with the references. also, features of space-borne sar signals are described. in this description, bandwidth, pulse repetition frequency, imaging duration time, and power density are investigated using analytical relations.