| Recently, with the development of digital signal processing, radar emluator theory and technology has been improved a lot, so does the research of radar simulator. This dissertation, based on the project of airborne fire-control radar system simulation and realization, absorbed the successful experiences of last generation radar simulator, which is compartmentalize modules by function using radar design theory, at the same time offered a more self-contained design scheme with modern radar theory and computer simulation technology. Finally, the developed radar simulator not only has air-to-air function like sorts of scan modes in airspace and airwar mode, but has innovative design about air-to-ground, air-to-sea function, especially consummate the environmental module like clutter simulation, which makes radar simulator working on more real environment.This dissertation deeply researches the radar signal processing theory and sets uf the whole frame of radar system based on that theory. At last realizes all kinds of working modes in air-to-air, air-to-ground, air-to-sea function of airborne fire-control radar. Because of the ground/sea clutter module, air-to-ground, air-to-sea mode such as GMTI, AGR, SEA#1, SEA#2 become practical.This dissertation based on statistical mode depict the amplitude characteristic and power spectrum characteristic, using ZMNL (Zero Memory Non-linearity) and SIRP (Spherically Invariant Random Process) to realize the clutter data. The ant directional diagram model and clutter echo model are presented, and the clutter series which submits Rayleigh distribution in amplitude fluctuation and Gausses distribution in power spectrum distribution are simulated. The principle of grid superposition for computation of clutter is discussed. According to the model of scattering factor of clutter, the amplitude fluctuation and spectrum characteristics of clutter are analyzed. The superposition method of clutter cell signal is provided and the three-dimensional power spectrum is plotted. The clutter model presents an application to different radar parameters, carrier parameters, or different environmental parameters. It provides a powerful basis for restraining clutter. Finally, this dissertation researched the framework of radar system simulator, simulation thread structure and implementation methods. In addition, make the whole radar simulator system a DLL (Dynamic Link Library), so that can be used directly by large avionics system. |
