Coherent radar processing in sea clutter environments, part 1: Modelling and partially adaptive STAP performance

Performance of space-time adaptive processing (STAP) with adaptive matched filter detection for maritime surveillance is assessed using simulated maritime surface targets embedded in real radar sea clutter data and compared with conventional pulse-Doppler processing. Pre-Doppler and post-Doppler suboptimal STAP are examined, with pulse repetition interval (PRI)-staggered post-Doppler shown to provide best overall detection and constant false alarm rate performance. A two-component clutter model fit is used to explain variations of clutter characteristics and detector performance with Doppler frequency

Coherent radar processing in sea clutter environments, part 2: Adaptive normalised matched filter versus adaptive matched filter performance

The maritime surveillance performance of the adaptive normalised matched filter (ANMF) detector structure against real multichannel, medium grazing angle, radar sea clutter data processed via space-time adaptive processing (STAP) is assessed and shown to exhibit constant false alarm rate (CFAR) performance characteristics which diverge from predictions over a large segment of the endo-clutter spectrum. The non-CFAR behaviour is linked to the existence of a two-component clutter model composed of contributions from Bragg and fast scattering mechanisms

Coherent MIMO radar for GMTI

In addition to imaging, coherent MIMO radars have a strong potential for detecting moving objects and estimating their parameters. This paper investigates different MIMO schemes based on spatial, waveform, and frequency diversity for their GMTI capability. The fully configurable MIMO radar MIRACLE X is taken as the baseline design for comparing the different approaches

A generalization of DPCA processing for multichannel SAR/GMTI radars

This paper generalizes the well-known displaced-phase-center antenna (DPCA) method for efficient ground moving target indication (GMTI) with a two-channel synthetic aperture radar (SAR) to any multichannel SAR/GMTI radars independent of the number of receive channels. This processing method called extended DPCA (EDPCA) is derived in this paper and is applied to data acquired with the Canadian RADARSAT-2 satellite. The expected GMTI performance of RADARSAT-2 after EDPCA processing is compared to results achieved with measured RADARSAT-2 data recorded during several trials in order to validate the developed theory

Adaptive normalised matched filter performance in medium grazing angle sea clutter

The detection performance of the adaptive normalised matched filter (ANMF) detector structure is assessed against real multi-channel, medium grazing angle, radar sea clutter data processed via space-time adaptive processing (STAP). Significant departures from constant false alarm rate (CFAR) performance are observed and linked to discrepancies between the assumed form of the spherically invariant random process (SIRP) which is used to derive the ANMF detection statistics and the actual form of the stochastic model representing the real world clutter characteristics

High-resolution wide-swath SAR

This chapter presents the principle of high-resolution wide-swath synthetic aperture radar (SAR), a means for imaging wide areas at high resolution. The material covers the limitations of achieving wide-swath and high-resolution with a traditional SAR, the basic idea of using a multi-aperture SAR to overcome this limitation and current implementations where multi-aperture (or multiple antenna) systems collect data in an ideal configuration. Overviews of approaches to processing data collected in nonideal configurations, such as when the data are collected with non-uniform sampling and/or when they are collected with a squinted system, are then introduced. Armed with an overview, the chapter introduces the theory of multi-aperture SAR processing with the objective of generalizing the concept of high-resolution wide-swath to higher resolution, wider-swath SAR. This enables application of the added degrees of freedom to other modes such as spotlight and high-resolution stripmap. In order to present the theory and the generalizations, and in consideration of possible future systems, the theory is derived in the wavenumber domain for wideband and/or widebeam, space-based systems with special cases for narrowband systems presented as appropriate. In contrast to much of the current literature, the theory views the antenna patterns as the key provider of the additional degrees of freedom and proposes to utilize other pattern characteristics in addition to the phase-centre separation to improve imaging. For this reason, special care is taken in developing the antenna pattern dependence in the signal model. The approach for signal reconstruction focuses, mainly, on the minimum mean-square error method as it is quite general and includes, as special cases, the well-known projection approach as well as the space-time adaptive processing (STAP) approach. Further, it inherently, simultaneously improves the geometrical and radiometrical resolution due to favourable weighting by the antenna pattern and a less aggressive ambiguity prescription as compared to other techniques. The approach also naturally incorporates other more generalized system configurations where, for instance, the antenna patterns have, not only different phase-centres, but also different shapes or different pointing directions. As an added feature, the presented method is robust against matrix inversion problems which can render the projection approach intractable. The special case of a phased-array multi-aperture system is presented