Passive Radar Beam Sweeping for Single-Receiver Object Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing passive radar receiver systems for detecting physical objects require two separate receivers and suffer from inaccuracies due to unknown or imprecisely determined transmitter beam sweeping periods, leading to errors in range estimation and object detection.
Innovation Solution
A method and system that utilize a single receiver to determine the location of physical objects by measuring the transmitter beam sweeping period if known, or employing random receiver beam sweeping if unknown, and calculating the relative time of arrival between line-of-sight and target paths using a beam sweeping schedule.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If two separate receivers (reference receiver and surveillance receiver) are used in existing passive radar systems, then object detection capability is provided, but device complexity increases and measurement precision deteriorates due to synchronization errors
Solution Approach 1:
The patent merges the functions of reference receiver and surveillance receiver into a single passive radar receiver. The single receiver performs both reference signal reception and target signal reception by sequentially switching between different receive beams, eliminating the need for two separate receivers while maintaining detection capability and improving synchronization accuracy.
Solution Approach 2:
The patent employs periodic beam sweeping where the single receiver alternates between receiving reference signals and target signals in a periodic manner. The receive beam is swept through different spatial directions at regular intervals, allowing the system to collect both reference and target signals periodically, which resolves the contradiction by using time-division multiplexing instead of spatial separation.
2Measurement precision
If the transmitter beam sweeping period is unknown or imprecisely determined, then system operation is simpler, but measurement precision deteriorates due to errors in range estimation
Solution Approach 1:
The patent implements a feedback mechanism where the receiver measures the transmitter beam sweeping period by analyzing the periodicity of received signals. The system continuously monitors the signal characteristics, detects the beam sweeping pattern, and adjusts its beam sweeping schedule accordingly, creating a closed-loop system that improves measurement precision through active feedback.
Solution Approach 2:
The patent performs preliminary measurement of the transmitter beam sweeping period before conducting target detection. The system first acquires and analyzes reference signals to determine the beam sweeping period, then uses this pre-acquired information to configure the receive beam sweeping schedule, ensuring accurate range estimation before actual target detection begins.
3Measurement precision
If random receiver beam sweeping is used when TBSP is unknown, then ease of operation is improved, but measurement precision deteriorates compared to TBSP-based beam sweeping
Solution Approach 1:
The patent implements a dynamic beam sweeping strategy that adapts based on the known or unknown status of the transmitter beam sweeping period. When TBSP is known, the system uses synchronized TBSP-based beam sweeping for optimal precision. When TBSP is unknown, the system transitions to random beam sweeping and simultaneously measures TBSP, then switches to synchronized mode once measurement is complete, providing dynamic adaptation to operational conditions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Accurately detects and tracks physical objects using a single receiver, reducing errors in range estimation and improving object detection accuracy by determining the relative time of arrival and propagation times.
Implementation Method 1
A passive radar receiver system may include a single receiver or multiple receivers that are not co-located with a transmitter. The system is considered passive because the receivers are not co-located with the transmitters.
Implementation Method 2
The signals are reflected and/or scattered by the physical object and propagate on a path 128 to finally arrive at the surveillance receiver 108.
Implementation Method 3
determining a relative time of arrival of radio signals between the LoS path and the target path, and determining the propagation time on the LoS path and on the target path
Data Source
AI summary
A method of determining the location of a physical object using a passive radar receiver includes determining if a transmitter beam sweeping period (TBSP) is known, and executing a TBSP-based receiver beam sweeping if the TBSP is known. If the TBSP is not known, determining if the TBSP can be measured, and executing the TBSP-based beam sweeping if the TBSP can be measured. The method includes executing a random receiver beam sweeping if the TBSP is not known and cannot be measured. The method includes determining a relative time of arrival of radio signals between the LoS path and the target path, and determining the propagation times on the LoS path and on the target path. The method includes determining the location of the physical object using the propagation times.