Laser Measurement System Of The Radar Antenna Stabilization Platform

Airborne SAR requires that radar's antenna should motion steadily along beeline across target area. On the contrary, frequent changing of flight stance, such as yawing, rolling and pitching greatly decreases the quality of SAR's imaging including resolving power and image contrast. It also can cause geometric aberration and even imaging failure. Therefore, an antenna stabilization platform is built for a high resolving power Airborne SAR to image continuously in wide area. It is also necessary and important to build a complete and precise test system to ensure and improve the performance of the platform.The key problem is how to precisely measure and evaluate the major technique indexes of antenna platform and its control unit, especially track precision of the angle location servo loop. At present simple measure instruments, manual data input and calculation and manual-adjusting platform are still used to solve the problem, which cannot simulate the real condition and measure dynamic indexes of the platform. Generally speaking, domestic test method for SAR antenna stabilization platform is relatively behind the times, and automatic test system is still far from realization. It is imperative that high performance Automatic Test Equipment (ATE) should be built to test the platform owing to the development of SAR.In this situation, ATE of SAR antenna stabilization platform based on virtual instrument (VI) is brought forward. Firstly, ATE simulates plane's angle movement by the simulator. Secondly, it acquires data of the simulator's actual stance and converts these data to simulative inertial navigation signal to control the movement of the platform. Thirdly, it measures the response of the platform by laser measure system and some accessorial parameters. Finally, it completely measures and evaluates the platform's various indexes, such as the dynamic and static responses, anti-jamming performance, track precision etc. It will fill the domestic blank of ATE on SAR antenna stabilization platform and provide a controllable and realistically simulated test circumstance for the existing platform and various antenna platforms. It will promote the progress on control technique and the movement compensating techniqueof high resolving power SAR antenna stabilization platform.This paper mainly introduced the laser measure system on the SAR antenna stabilization platform test system. It analyzed the laser measure method on the measure of the slight rotation angle of SAR antenna, figured out the structure of system, and designed the signal processing circuit and developed the software program. It also gives the outline and performance of the whole system's structure and virtual device software.This study firstly introduced the Position Sensitive Detector (PSD) into the system to measure slight rotation angle of SAR antenna relative to ground reference frame. Meanwhile VI technology was utilized to organize the measure system and control the system by computer. This study also found out the method of measuring dynamic indexes of the SAR antenna stabilization platform and solved the key problem of the realization of ATE.