Design And Verification Of Some Key Algorithms For The Channel Simulation Of High Speed Aircraft

Because of the near space vehicles' high speed, acceleration and different posture changes, the air-ground link between vehicle and ground is becoming the core research content. These characteristics about near space vehicles result in the difference between the near space vehicles' air-ground link and conventional vehicles. The differences between them in the following several points: Firstly, the high speed and acceleration near space vehicles will result a big dynamic doppler shift; Secondly, the air out of vehicles will be ionized and become a plasma sheath; Thirdly, if the vehicle be in low elevation, it would be result in the multipath effect; Fourthly, the time of vehicle cross the space of rain will be very short. Commonly the research have two effective ways, one is in-situ observation, the other is simulation. Because the in-situ observation is very difficult, the simulation is the main method to study the near space vehicles with hypersonic speed air-ground channel.In this paper have researched the air-ground link channel based on near space vehicles with hypersonic speed, modelled and analyzed the special features on the process of flying about near space vehicles with hypersonic speed, proposed some models on plasma sheath, multipath channel based on landforms and low elevation, and rain attenuation suits on near space vehicles, given the algorithms of these models. And then tested and simulated these models. The main work includes:1. Analyzing the process of flying on near space vehicles systematically. Divided this process into several modules: Doppler effects, plasma sheath, multipath with low elevation and rain attenuation, and describing plasma sheath, multipath with low elevation and rain attenuation in detail.2. For the big time and space complexity of FDTD, this paper uses Equivalent wave impedance method to decrease the time and space complexity on the basis of accuracy. And as for low elevation multipath, try to model the multipath environment, calculate based on landforms and implements the algorithm. At last, this paper analysis the route of near space vehicles with hypersonic speed and model a new rain attenuation model applied to the high speed near space vehicles, implements the core algorithm.3. This article simulate and test the algorithms of plasma sheath, low elevation multipath and rain attenuation.The research and test show that some new algorithms about near space vehicles with hypersonic speed have reached the goals. These modules can be combined into channel simulator, and it will be a effective tool to analysis near space vehicles with hypersonic speed channel.