Multifunction Radar Subarray Segmentation for Simultaneous Air-Ground Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Airborne radars face challenges in simultaneously performing air/air and air/ground detection functions due to limited angular coverage and interruptions in aerial tracking during SAR imaging, which compromises mission effectiveness and introduces false alarms from spurious ground echoes.
Innovation Solution
A multifunction radar with an antenna subdivided into distinct portions for transmission and reception on separate frequency bands, using space-time autocorrelation matrix estimation and statistical tests to detect aerial targets, accounting for missing data and spurious ground echoes, and employing a sliding time window for improved processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If SAR imaging is performed with long illumination time to achieve high resolution, then image quality is improved, but aerial tracking operations are interrupted for extended periods
Solution Approach 1:
The antenna is divided into multiple independent subarrays that can be independently controlled. During SAR imaging, only specific subarrays are activated for ground illumination, while other subarrays remain active for air surveillance, enabling simultaneous operation without mutual interference
Solution Approach 2:
The patent transitions from temporal multiplexing (sequential operation) to spatial multiplexing (parallel operation in different angular directions). By utilizing the spatial dimension through multiple subarrays pointing in different directions, the system achieves simultaneous air/air and air/ground functions without time interruptions
2Device complexity
If a single antenna is used for both air/air and air/ground functions, then device complexity is reduced, but false alarms occur due to spurious ground echoes
Solution Approach 1:
The single antenna is segmented into multiple subarrays that can be independently controlled in space and frequency. This segmentation allows the system to maintain a physically simple single-antenna structure while achieving functional separation through spatial and spectral filtering, thereby reducing false alarms from ground echoes
Solution Approach 2:
Different subarrays of the antenna are assigned different local qualities (frequency bands and spatial directions). Air/air detection uses specific frequency bands and angular sectors, while air/ground imaging uses other bands and directions, allowing simultaneous operation with minimal interference and reduced false alarms
3Adaptability or versatility
If color transmission techniques with multiple subarrays are used to perform simultaneous radar functions, then functional versatility is improved, but antenna structure complexity increases
Solution Approach 1:
The patent implements a universal antenna structure where a single physical antenna serves multiple functions (air/air detection, air/ground detection, SAR imaging) simultaneously through intelligent signal processing and subarray control, eliminating the need for separate specialized antennas for each function
Solution Approach 2:
The antenna is divided into controllable subarrays that can be independently activated for different functions. This segmentation enables versatile simultaneous operation while maintaining a relatively simple overall antenna structure, as the complexity is managed through software/control rather than physical multiplication of antenna elements
Data Source
AI summary
A method for detecting targets, implemented by a multifunction radar wherein the radar comprises an antenna subdivided into at least two portions and is configured to transmit at least two types of signals on distinct frequency bands and to perform at least one ground detection or imaging function. During the transmission phases of an antenna portion, the reception of each antenna portion of the radar is cut. The method comprises, for each range gate, a step of reception of signals, a step of estimation of the autocorrelation matrix associated with the interferences the ground returns and from the thermal noise of the radar and a step of target detection using a test of the generalized maximum likelihood. A multifunction radar configured to implement the method for detecting targets is provided.