|8.1 STAP for radar
By: Allan O. Steinhardt
Booz Allen Hamilton
and: Joseph R. Guerci
This paper presents a survey of the challenges associated with STAP applied to real world radar problems. We then discuss solutions that have proved viable and why, and provide hints at what may be in store in the future. A primary contention is that better physical insight is the key to better STAP. We appear to have nearly exhausted the benefit of theoretical refinements on existing elegant, though inadequate mathematical statistical models.
|8.2 Canonical framework for describing suboptimum radar space-time adaptive processing (STAP) techniques
By: Sebastien De Greve
University of Liege
and: Fabian D. Lapierre
University of Liege
and: Jacques G. Verly
University of Liege
We adress the problem of detecting slow moving targets from a moving radar system using Space-Time Adaptive Processing (STAP) techniques. Optimum interference rejection is known to require the estimation and the subsequent inversion of an interference plus-noise covariance matrix. To reduce the number of samples involved in the estimation and the computational cost inherent to the inversion, many suboptimum STAP techniques have been proposed. Earlier attemps at unifying these techniques had a limited scope. In this paper, we propose a new canonical framework that unifies all of the STAP methods we are aware of. This framework can also be generalized to include the estimation of the covariance matrix and the compensation of range dependence; it applies to monostatic and bistatic configurations. We also propose a new decomposition of the CSNR performance metric that can be used to understand the performance degradation specifically due to the use of suboptimum method.
|8.3 Comparison of the radar clutter cancellation performance of post- and pre-Doppler STAP for GMTI from an experimental airborne surveillance radar
By: Paul G. Kealey
and: Ian P. Finley
Within this paper we report our study that compared the performance of
Pre-Doppler and Post-Doppler STAP processing algorithms applied to the same radar trials data, collected by QinetiQs Enhanced Surveillance Radar. The performance of these algorithms was quantified by clutter cancellation ratios and target signal improvement factors (the ratio of the signal to clutter+noise ratios with and without STAP processing). We have shown that Pre-Doppler and Post-Doppler STAP may be tuned to give the same level of clutter cancellation.
We present results in which bright target signatures are seen to affect the STAP processors and reduce the overall clutter cancellation. We have found that for our two phase center trials radar data, PRI staggered Post-Doppler STAP gives greatly enhanced clutter cancellation compared to the simple fixed window Post-Doppler STAP. The application of either moving window or auxiliary bin Post-Doppler STAP was found to degrade the processor output. The importance of normalizing the final range Doppler map to prevent the amplification of thermal noise and remove the weight-norm variation as a function of Doppler is shown to be a critical step to allow interpretation and application of detection algorithms after STAP processing.
|8.4 Cancellation of clutter and e.m. interference with STAP algorithms. Application to live data acquired with a ground-based phased array radar
By: Alfonso Farina
and: Luca Timmoneri
This paper shows that space time adaptive processing (STAP) can be fruitfully applied also to ground based radar to simultaneously cancel clutter and e.m. interference (e.g.: jammer). This is demonstrated by processing live data recorded by a C-band phased-array radar demonstrator having three spatial channels and few tents of coherent received pulses. The processing is done by emulating, on a software program, a systolic algorithm which is amenable for parallel processing thus allowing to reach the real time requirement. This paper opens up the way to a more extensive application of STAP which, up to now, is limited only to radar on board of moving platform. In fact, it can find a role in ground based and ship borne radar where clutter and jammer are contemporaneously present in the radar echoes and their characteristics (e.g.: direction of arrival, power, spectral shape) are not known a priori.