Jacques E. Cilliers

Performance prediction for a coherent X-band radar in a maritime environment with K-distributed sea clutter

In this paper, theory is developed for the prediction of the false alarm (PFA) and detection (PD) performance of surface targets in K-distributed sea clutter detected by means of Doppler processing techniques. Vital to this analysis is the inclusion of the correlation properties of the sea clutter between all the pulses within a burst of pulses. The resultant technique allows for the prediction of PFA and PD for each of the bins in the output of the Doppler processing stage of a fixed-threshold detector. The technique provides the ability to specify different thresholds for each of the Doppler bins. The analysis is extended to include Swerling type 1 and 2 targets for the calculation of PD. The performance of a noncoherent detector is provided for comparison. Results that demonstrate the application of the developed theory are also presented.

Evaluation and performance comparison of detection algorithms in a maritime environment

In this paper, a framework will be proposed for the evaluation of detector algorithms in a maritime environment. Performance metrics and test cases will be defined to allow the impartial comparison of different detectors. In this framework the main approaches for detector comparison are numerical simulation and the use of recorded sea clutter and boat reflectivity data. Available data suitable to the fair comparison of different algorithms will be highlighted, with results for a selection of algorithms. The proposed framework, performance metrics and baseline cases give researchers and system engineers the ability to quantify system performance in a complex clutter environment and to evaluate the effectiveness of a particular detector (or radar design(s)) as compared to another.

Introduction of low probability of recognition to radar system classification

This paper proposes the addition of low probability of recognition (LPR) to the electronic warfare classification of radar systems. LPR radars focus on deceiving electronic support (ES) receivers by selecting waveforms which are agile in their parameter spaces, or by mimicking existing transmitters. LPR provides an additional mechanism to achieve covert operation in a way which builds on low probability of interception (LPI) and low probability of detection (LPD) techniques. The challenges and opportunities of LPR techniques are considered, and some examples of existing waveforms which are suitable for LPR radars are provided.

X-Band high range resolution radar measurements of sea surface forward scatter at low grazing angles

Radar measurements of a radar calibration sphere test target suspended in sea surface multipath propagation conditions are reported. Wideband measurements together with high range resolution (HRR) processing were employed to resolve the direct reflection component and sea surface reflected multipath components of the received signal. The temporal correlation characteristics of the resolved single bounce multipath signal component are investigated, which shows that a strong temporal correlation in the sea surface forward scatter component exists. Based on this measurement, we propose a temporal correlation extension to an existing low-angle propagation model, together with a correlation filter structure to realize the correlation extension in computer simulation.

A Wideband Beamformer Extended to MIMO Radar

MIMO radar algorithms are the latest generation of techniques which can be applied to phased array radars. They offer the potential to improve the resolution, number of targets that can be identified, and ¿exibility in beam pattern design. To date, most of the work on MIMO radar has been performed assuming the signals are narrowband. However, wideband signals can also improve radar resolution, among other benefits, and are sometimes unavoidable when stringent range resolution specifica-tions must be met. This paper presents a method for extending the MIMO narrowband model to a wideband model. This is necessary to obtain improved results from parameter estimation when the transmitted signals are wideband. The results show that the method greatly improves the results compared to those obtained when no techniques are implemented to compensate for a wideband signal. However, best performance is still obtained with a narrowband signal, and therefore the technique presented might only be of interest when a wideband signal is required.

Case study on low probability of recognition (LPR) radar using GSM

A practical investigation of the application of low probability of recognition (LPR) to Global System for Mobile Communications (GSM) systems within radar waveform design is provided. LPR radars focus on deceiving electronic support (ES) receivers by selecting waveforms which emulate the waveforms of communication transmitters and thus provide an additional mechanism to achieve covert operation. The advantages and drawbacks of different levels of LPR are analysed from both the radar and ES-receiver perspectives. Some LPR techniques have only a minor effect on radar performance while requiring vastly more complex ES systems to address, and vice versa. This means that both radar and ES systems must be considered when evaluating LPR techniques.