Modeling And Simulation Of Radar Echo Of Airport Runway Scenario

Foreign Object Debris can severely injure airport or airline personnel or damage equipment. FOD can be generated from personnel, airport infrastructure, the environment and the equipment operating on the airfield. Types of potential damage include: cutting aircraft tires, being ingested into engines; or becoming lodged in mechanisms affecting flight operations. FOD will not only damage the plane, but also take away people’s lives, and also effect the normal operation of the airport and so on. FOD surveillance radar is used to monitor foreign objects on runways and detect the target timely and accurately. FOD are generally static targets on runways, so the moving target detection technology isn’t suited for detecting FOD. Worsely, echoes from background are stronger than that from FOD and the clutter has interference with FOD detection. So the study of FOD detection technology is based on the reasonable clutter model. The study of runway surroundings and analysis of scattering characteristic of target and clutter is conducted and the echo model of runways scenario is derived.Firstly, the geometrical model of FOD scene is established, the radar echo signal is generated with the method of coherent video signal simulation by studying scattering characteristic of target and clutter in in a single resolution cell, and the basic principle of coherent video signal simulation is given. Secondly, the calculation methods of normalized RCS of rough surface, which include single scattering model and multiple scattering model. Analysis of the factors which effect normalized RCS, such as roughness, the dielectric constant, correlation function and so on. The normalized RCS is computed of dry surface, wet surface, icy surface and snow surface under the condition that surface is approximately smooth surface.Thirdly, the clutter model of the scenario is studied, experimental data indicate that large deviations from Rayleigh statistics are observed in situations such as low grazing angles and high-resolution radar which are similar to the situation of FOD surveillance system. Thus non-Rayleigh distribution model is introduced in this paper which is suitable for FOD, such as the lognormal distribution, weibull distribution and K distribution. The probability density function of the three distributions is analyzed and the approximation of them is given under the certain error. And the two methods of generationg the clutter is given, zero memory nonlinearity(ZMNL) and spherically invariant random process(SIRP), and the clutter of lognormal distribution, weibull distribution and K distribution are generated in MATLAB. Fourthly, empirical formula of calculation RCS of FOD target is given, the factors that effet RCS are analyzied such as attitude angle, target size and transmitting frequency and so on. Lastly, the simulation of FOD radar echo signal is conducted considering the scattering characteristic of clutter and target, and pulse compression processing of echo signal is conducted and the clutter distribution parameters are estimated, the clutter statistical information is obtained.