Bistatic Radar of Space Debris Using Correlation-Phase Direction Finding

In the paper, a diversity radar system is proposed for monitoring space debris in near-Earth orbit. It combines a high-energy radar and a Correlation-Phase Direction Finder (CPDF), providing high accuracy in determining the angular position of an object with small antenna sizes. The purpose of this paper is to present the architecture of such a radar system and determine its potential capabilities in angular measurements. The scenario considered takes into account the beam park observation method. According to it, the radar combined antenna and CPDF transmitting antennas are directed in a fixed direction, while the radar and CPDF receivers receive echo signals coming from an object that passes through the common field of vision of the radar antenna and the CPDF antennas upon completion of the radar emission cycle. Quantitative estimates of the efficiency of the system under consideration are performed based on the theory of optimal radio reception for specific radio engineering facilities of the MEOS station (Russia) consisting of the “Cobalt” radar based on the TNA-1500 radio telescope and the “Rhythm-M” CPDF. Under the specified observation conditions, the measurement error of the direction cosines of the detected object does not exceed 2×10-5 for a single sample generated during the duration of the received signal reflected from a fragment of space debris 11 cm in size and greater at a distance of up to 750 km. The fragments up to 36 cm in size can be located at a distance of up to 1700 km, and large fragments up to 1 m in size – at a distance of up to 3000 km.