Title

The probability of detection improvement inside the fusion area via scan rate regulation of a two radar system

Date of Award

2016

Degree Name

Ph.D. in Electrical Engineering

Department

Department of Electrical and Computer Engineering

Advisor/Chair

Advisor: Michael C. Wicks

Abstract

The objective of this research is mainly to focus on three areas of study. First is to improve bistatic mechanically scanning radar (MCR) detection performance and fused track formation via joint scan-to-scan processing (SSP) and scan rate modulation. The second area of the study is improving the probability of detection of two monostatic radars via scan rate reduction and using probability fusion rules. The third case study is enhancing the probability of detection of two monostatic radars by numerical scan rate regulation. The first study employs two mechanically scanned radars (MSRs), with one operating as a master control radar (MCR) and the other a secondary slave radar (SSR). The MCR is designed to operate under conditions of variable scan rate, including scan rate modulation. These radars also have the potential to achieve a very high scan rate, and, therefore, are well suited for track-while-scan processing. The SSR is under the control of the MCR and responds mechanically to initial detection declarations and track formation handoff from the MCR. In this situation, detection and track performance is improved because both radars jointly process the monostatic and bistatic returns. Even as these radars interrogate the same geospatial coordinates, the return signals may exhibit different cross section statistics because scattered signals are observed from different viewing angles. As such, all detection decisions are computed using simple logic rules (AND, OR etc.). The SSR rotates at a potentially much slower rate to provide longer dwell time measurements, to enhance single dwell detection performance. However, the SSR may break track, due to the slow update rate. False alarms are reduced by scan-to-scan track processing, which exploits detection declaration history. The decision is made after a certain number of scans. If there is detection declaration in m-out-of-n scans, a target is declared, if not, a threshold crossing is assumed to be a false alarm. With multiple declarations, distinguishing between two closely spaced targets is achieved by comparative analysis between track profiles and detections. A declaration is assumed to be correlated with its nearest neighbor. If the detection is far removed in distant from a track, this declaration is assumed to be from another target. Using two radars combines the advantages of a large number of scans, high probability of detection and low probability of false alarm. Therefore, all essential track-while-scan requirements are satisfied. The second case discusses probability of detection enhancement at the fusion (area scanned by two monostatic radars). The first radar scans at a fixed scan rate while the other one is under scan rate modulation. The enhancement done in the same ways that used in case I. The scan rate modulation increases the probability of detection and SSP maintain the probability of false alarm within the permissible limit. The third case investigates a system consisting of two monostatic coherent radars. The first radar has three different scan rates while the second radar scans at a fixed rate. The goal is to analyze the probability of detection at the fusion area to control the scan rate inside the fusion area to provide the minimum satisfactory probability of detection per scan with highest scan rate. Decreasing the fusion scan time increases the number of scans, which improve the cumulative probability of detection inside and outside the fusion area. The scan is regulated for each antenna beam. Once the detection is declared the estimator predict the target appearance time within the fusion area. Then the controller uses the rule matrix to select the convent scan rate in order to improve the total performance inside and outside the fusion area.

Keywords

Radar receiving apparatus, Radar transmitters, Bistatic radar, Coherent radar, Electrical Engineering, Probability of Detection inside the fusion

Rights Statement

Copyright 2016, author

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