Radar Scan-to-Scan Integrator Using Arcuate Search Windows
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Solution Overview
Problem
Radar systems face challenges in accurately determining the angular position of targets due to finite beam width, leading to uncertainty in cross-range position and increased false alarm rates when using rectangular search windows aligned with Cartesian coordinates, which results in larger search areas and higher probabilities of erroneous correlations.
Innovation Solution
The implementation of a scan-to-scan integrator that uses both rectangular and arcuate search windows, with the arcuate window defined by arcs A1, A2, to refine the target detection zone, allowing for more accurate integration and reducing false positives by considering both range and angular position estimates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a rectangular search window aligned with Cartesian coordinates is used, then computational simplicity is improved, but the search area increases and false alarm correlation probability increases
Solution Approach 1:
The search window is divided into two distinct components: a rectangular window for computational efficiency and an arcuate window for accuracy. The rectangular window handles the basic search area aligned with Cartesian coordinates, while the arcuate window refines the search zone based on the ideal arcuate lozenge shape, segmenting the functions to balance simplicity and reliability
Solution Approach 2:
An arcuate window is introduced to define the search area, replacing the purely rectangular approach with a curved boundary that follows the ideal arcuate lozenge shape. This curvature better matches the actual uncertainty region in range-Doppler space, reducing the search area while maintaining computational tractability through the rectangular-Cartesian framework
2Reliability
If the number of scans N for integration is increased, then target detection reliability is improved, but the time required for detection increases
Solution Approach 1:
The system performs preliminary integration over N scans before making a final detection decision. By accumulating evidence across multiple scans in advance and using the refined arcuate search window to focus the integration area, the system prepares the detection state progressively, allowing reliable targets to be confirmed while reducing false alarms, and the threshold M≈N/2 provides a balanced decision criterion
Data Source
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AI summary
A scan-to-scan integrator for use in radar apparatus comprises means for defining a search window for use in verifying a candidate detection. The window is bounded by the intersection of a first zone and a second zone, wherein the first zone comprises a rectangular reference frame aligned detection window, and the second zone comprises a range estimate tolerance region defined by a range estimate for the candidate detection and predetermined tolerance limits