Airborne Millimeter Wave Collision Avoidance Radar Signal Processing Based On Fpga Technology Research

Since the advent of the helicopter, it is widely used by virtue of its excellent flight performance and unique aerodynamic characterstics in a number of fields, and has a broad prospects for development. It often need to perform tasks in the low-altitude complex environment. Helicopter flight safety will be seriously threatened if lack of detailed flight path and detecting and sensing means. Therefore, the study on the helicopter collision avoidance radar has been paid more and more attention.With the background of practical engineering applications of National Electric Net Ltd, the working mechanism and design key points of the millimeter wave radar system are deeply analyzed in this paper, the main works in this paper has been done as follows:First, the research and development situation of the domestic and foreign helicopter-borne millimeter wave collision avoidance radar are introduced, besides, the key design points and difficulties of this radar are analyzed.Second, we deeply analyze the nature and signal processing methods of LFMCW signal, including MTD design and CFAR processing.The Doppler factor and FM linear factor effect on measurement accuracy and the corresponding solutions are discussed in theory.Third, among all the obstacles threatening the safety of helicopters, power line is the most difficult to detect because of its small size. Therefore, the RCS of the power line is analyzed. We use signal in coherent integration and non-coherent integration means to improve its echo SNR. However, due to the movement of the helicopter, distance migration phenomenon will be produced if we do long time integration, and it wound seriously affect the integration effect. In order to solve this problem, this paper also study the related solutions, including direct compensation algorithm、algorithm based on coherent within segment non-coherent accumulation among segment and keystone algorithm. This paper also discussed a mean which use of polarization information to improve the SCR of the power lines.Fourth, a helicopter-borne millimeter wave collision avoidance radar signal processing system based on FPGA was designed and implemented. In this paper, the signal processing implement scheme is designed and realized, and the software part is realized with Xilinx ISE10.1software integration environment. Finally, the measured datas are analyzed.