Design and development of a real-time multi-DSPs and FPGA-based DPOS for InSAR applications

With the development of the novel remote sensing system such as array antenna interference synthetic aperture radar (InSAR), it is in urgent demand to design and develop an airborne distributed position and orientation system (DPOS) to provide multi-node time-spatial reference information accurately. To solve the problem, this paper describes a novel design and fabrication of DPOS, which integrates the main strapdown inertial navigation system (SINS), global position satellite (GPS), multiple slave inertial measurement units (IMUs), and distributed navigation processing computer system. In the proposed system, multiple digital signal processors (multi-DSPs) are used for multiple inertial navigation solutions and Kalman filter computations, and a field programmable gate array is used for creating an efficient interface of the GPS and multiple IMUs with the multi-DSPs. This also helps reduce the count of the total chips, resulting in a compact system. The system is designed to provide synchronous multi-node real-time high-precision navigation solutions with an update of 200 Hz. In order to verify the performance of DPOS, the real flight test, which combined InSAR and DPOS, was conducted and showed the proposed system can help compensate the motion error of the high-resolution interference mapping more efficiently than the single POS.