Simulating dispersed pulse weather echo using simple radar pulse echo

We addressed the problem of simulating the echo of a dispersed pulse from meteorological scatterers. The purpose was to test doppler tolerant range sidelobe suppression techniques, as well as other signal processing techniques. We devised a technique for simulating such echoes using existing simple radar pulse data. If the scatterers were stationary, the simulation would consist simply of passing the simple pulse echo complex envelope through a dispersive network having the proper dispersive impulse response for producing an output as if the dispersed pulse had been transmitted. In effect, this interchanges the scatterer "filter" system with the network or mechanism that produces the dispersed pulse. If the scatterers are moving, as is the case with meteorological echoes, this interchange cannot be done. Instead we must simulate the randomly varying medium from the echo data of a simple pulse. The situation is complicated by the fact that we must know the medium fluctuation characteristics on a time scale corresponding to the propagation time between adjacent range samples, a time that is generally a fraction of a microsecond. However, the only samples available at each sampled range instant are the complex envelope echo values separated by the pulse repetition period. Interpolation is used to estimate the values between time instants separated by the pulse repetition period. In addition, a form of complex harmonic interpolation is derived, a form yielding simulated values much closer to what would actually be observed with an actual dispersed pulse transmission.<>