Research Of Air Target Imaging Detection Based On GNSS Reflected Signals

Aerial target detection based on GNSS signal means using the signal as a bistatic radar system emitting source, after the target area illuminated by the receiver to process the received signal to achieve detection method of the air target.Different from traditional single radar detection method, in bistatic radar detection system, the transmitting antenna and receiving antenna lay on the different location, it is easy to close and intercept enemy reconnaissance. Compared to other non-cooperative signal source,it has other advantages,such as rich signal sources,easy synchronization and continuous signal.In the thesis,I used FEKO, a kind of the electromagnetic simulation software,to simulate the bistatic radar RCS of air targets. On the basis of the simulation,the conclusion that air targets is easier to detect when the air reciver has a big bistatic radar angle was made.Then, the thesis analyzed autocorrelation and cross-correlation properties of the C/A code of GNSS signals.Further,the advantages which GNSS signals relatived to other cooperrate siganl sources was analyzed bases on the qualitative analysis.For air targets detection system madel,we analyzed and simulate the two-dimensional delay doppler spectrum,then Put forward a method which detecting a suspected target by imaging in the surface,and used the information which was from received beam of reciver to determine whether there were the air targets. In combination with imaging features,we made a image filtering by lateral inhibition filter method,and implement target detection by using the adaptive threshold method of background suppression to process the filtered image. Finally, the MFC framework structures based on the use of simulation scenarios that demonstrate complete control and STK control, to complete Aerial targets detection systems based on GNSS-R.