Space Based Radar (SBR) Space Time Adaptive Processing (STAP)

Space based radars by virtue of their physical location illuminate a very large land mass thereby generating a significant amount of clutter that is also Doppler dominant because of the large relative velocity of the transmitter platform compared to the land mass. The problem in this case is to detect and identify slowly moving ground targets in presence of Doppler-dominant clutter and noise in a nonstationary environment. A number of Space Time Adaptive Processing (STAP) algorithms that have been modified to address the small sample support problem in a nonstationary environment are presented here for slow-moving target detection by making use of several high-resolution pre-processing techniques on the space-time data cube. In addition, two classes of model based high resolution algorithms are proposed for target classification and feature extraction by exploring the early- and late- portions of the target returns from the range-bin data. Instead of using conventional FFTs, one of these high-resolution algorithms will be modified to accurately estimate the actual target azimuth and Doppler parameters by operating on the spatial and temporal portions of each range-bin data. Further clutter suppression and target enhancement through optimum transmit waveform design is also proposed by maximizing the output SINR. BENEFIT: Robust Space Time Adaptive Processing (STAP) algorithms can be used in cellular base station technology to locate mobile users by utilizing a small number of data samples. As a result, communication systems such as cellular base stations, satellite communication systems and wireless LANs can benefit from small sample support STAP algorithms proposed here. Further these algorithms will be beneficial for high-resolution next generation meteorological radars. The robust high-resolution STAP algorithms proposed here can significantly improve system performance for satellite based wireless communication systems. Since systems offering the maximum flexibility in terms of configuration and self adjustment are often the most cost-effective long-term solutions, the proposed approach with a selection of high-resolution robust algorithms offers an attractive solution. The proposed Phase I effort will provide the necessary key algorithms/methods for real-time implementation and analysis on a graphical user interface test platform for the Space Based Radar. The flexibility of the robust algorithms proposed here allows for the creation of a new value-added product that gives SBR designers an attractive solution for robust STAP. The proposed adaptive STAP algorithms also have potential use in future generation power-aware cellular receiver design to mitigate interfering signals, and next generation meteorological radars for accurate weather mapping. In addition, with suitable modifications they may be adapted to the bistatic case as well.