TARGET RECOGNITION

SUMMARY

Target recognition is a key military requirement and radar offers a long range, all-weather capability. However the only existing technique that can be considered mature is JEM (Jet Engine Modulation) identification and this suffers from limitations with respect to aspect angle and recognition range. This research aims to bring other techniques (range profiling and 2-D imaging) to a higher level of maturity, and particularly to understand the fundamental scattering characteristics of targets with the aim of making the techniques more robust.

MILITARY BENEFITS

Reliable long range, non-co-operative target identification is a key military need. Research in this field can benefit both current and future systems.

RESEARCH OBJECTIVE

The provision of an aircraft target signature database using existing experimental radars
An assessment of the feasibility and benefits of feature-based ID techniques for moving targets
Study of novel techniques for target ID in SAR imagery, taking into account the complex (rather than simply amplitude) signature
Robustness of ID techniques to minor differences in target configuration and to counter-measures
Development of a quantitative measure of the confidence in an identity declaration, especially when using modelled databases

RESEARCH OUTLINE

The work in this sub-theme is designed to answer specific questions which will quantify what radar can provide in the overall process of target identification. Radar has unique advantages- long range, all-weather operation, high precision range and Doppler measurement capability- but the operating wavelengths impose fundamental limits, especially on angular resolution. Use of other information (from other sensors, contextual, etc.) can greatly enhance the recognition capability. A ‘multi-functional’ capability of which radar will be a part offers the best prospect of meeting the operational need, the aim of this research is to determine what radar can contribute to the whole picture.

An important part of the work in this sub-theme is to gain a better understanding of scattering theories for high-resolution radar waveforms. The validity of theories, such as Rihaczek et al, which have challenged conventional assumptions need to be assessed so that their impact on current high-resolution radar waveform design and associated target classification techniques can be determined. Specific emphasis will be placed on the range resolution required to achieve a given classifier performance.

It is recognised that modelling alone will be insufficient to answer these questions, and that measurements of real targets are essential. An experimental facility with 0.6m resolution which can operate at I-band and F-band is available at BAE SYSTEMS Advanced Technology Centre and this will be used to support the work.

Existing identification techniques based on target templates are not robust. Based on the first stage of the research described above, the next stage will aim to find alternative approaches which are less critically dependent on knowledge of the precise details of the target, as well as knowledge of its position and orientation during the radar observation. An important additional aspect of this work is to derive a robust methodology for providing confidence measures for the identification process.

This research theme will also encompass the problem of target identification in SAR imagery. This problem, particularly critical to the requirements for rapid large area search, is aimed at finding targets of interest from a very large mass of data. Hitherto this has been considered as an image classification problem, but the complex radar signature contains much valuable information which is believed to be exploitable. Certainly, previous work on coherent change detection has shown the potential of this approach. This work will concentrate on complex image analysis as the basis of target detection and recognition.

CO-ORDINATION WITH EXISTING / PREVIOUS RESEARCH

This research builds on the very extensive background in radar NCTR in the UK and will be complementary to the Assisted (Automatic) Target Recognition work being carried out under the Improved Targeting TDP. The work will involve the principal researchers in this area (QinetiQ and BAE SYSTEMS ATC) and is backed up by the expertise of the DTC Consortium, particularly their knowledge of NCTR for MSTAR and Eurofighter. The work also has the advantage of access to an existing experimental facility which is crucial to achieving a robust, practical capability.

Leave a Reply

Your email address will not be published. Required fields are marked *