Research On Key Technologies Of Radar For Foreign Objects Debris Detection On Runway

Foreign Object Debris, abbreviated as FOD, refers to the objects that should not bepresent on the runway and may damage the system or aircraft. Foreign object debrishazards are very serious, causing both physical loss and economic loss. Therefore it isvery necessary to develop foreign object debris detection system. Currently, there aresome foreign object debris detection systems successfully developed in foreigncountries. These systems mainly use millimeter-wave radar technology and imageprocessing technology to achieve detection of foreign object debris. However, domesticresearch in this area is still at an initial stage. Therefore, the study of foreign objectdebris detection system has practical value.Based on airport runway foreign object debris detection radar, the system wasfirstly analyzed and radar system and parameters were determined on the basis of theanalysis. Then radar echo modeling and CFAR(Constant False Alarm Rate) werestudied. The main job is shown as following:1. Target echo signal is analyzed based on linear frequency modulated continuouswave system used by runway foreign object detection radar. Radar studied in thisdissertation is a close quarters radar scanning the ground while ground clutter is themain interference. Two statistical characteristics of radar clutter are introduced, whichare probability distribution function and power spectral density. The probabilitydistribution includes Rayleigh, Weibull, LogNormal and K. Power spectral densityincludes Gaussian, Markov and cubic. Two classic method of clutter generation, ZMNLand SIRP, are analyzed. Then single target echo signal and clutter sequence aresimulated based on MATLAB.2. As foreign object debris detection radar has characteristics of low grazing angleand high resolution, clutter would fluctuate sharply on the airspace. Thus it will causelarge loss of false alarm rate when uses traditional CFAR detection technology. Basedon the relatively stable of clutter in time domain, the clutter map CFAR detectiontechnology is put forward. Detection Performance of clutter map CFAR pointtechnology and plane technology is analyzed comparatively. Impact of detection probability caused by scan cycle, forgotten factor and signal-to-clutter ratio in differentfalse alarm rate is studied. Then a bi-parametric clutter-map CFAR algorithm isproposed. The algorithm estimates the sample mean and sample variance of themeasurement data, achieving stable detection threshold estimates through iterative.