Improved detection and track processing through scan-to-scan processing and scan rate modulation

Abstract

The objective of this research is to improve bi-static radar detection performance and fused track formation via joint scan-to-scan processing (SSP) and scan rate modulation. This concept 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 monostatic and bi-static 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 long dwell time measurements, which enhances 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 a 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.