Centralized TDOA Transmitter Location via Link Delay Calibration
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Solution Overview
Problem
Existing methods for locating uncooperative transmitters with unknown locations require expensive TDOA circuitry at each receiving station, increasing operational costs and complexity.
Innovation Solution
A method that centralizes TDOA calculations at a control station by using a calibration signal to subtract communication link delays, eliminating the need for TDOA circuitry at receiving stations and allowing geolocation of uncooperative transmitters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If TDOA circuitry is installed at each receiving station to locate transmitters, then location accuracy is improved, but device complexity and operational cost increase
Solution Approach 1:
The patent extracts the TDOA calculation function from individual receiving stations and relocates it to a central processing station. Each receiving station only performs signal reception and preliminary processing, while the central station performs the complex TDOA calculations using received signals from multiple stations, thereby reducing device complexity at receiving stations while maintaining location accuracy
Solution Approach 2:
The patent merges the TDOA calculation functionality into a centralized processing station that receives signals from multiple receiving stations. This consolidation allows all receiving stations to work together as a coordinated system, with the central station performing unified TDOA calculations to determine transmitter locations, reducing overall system complexity while preserving measurement precision
2Measurement precision
If TDOA circuitry is installed at each receiving station, then location capability is improved, but operational cost increases
Solution Approach 1:
The patent extracts the expensive TDOA calculation hardware from each receiving station and relocates it to a single central processing station. This extraction eliminates the need for multiple expensive devices at receiving stations, significantly reducing operational costs while maintaining the location capability through centralized processing
Solution Approach 2:
Instead of having each receiving station possess expensive TDOA circuitry, the patent uses multiple simple receiving stations that copy the same basic signal reception functionality. The complex TDOA calculation is then performed once at the central station using signals from these simpler receiving stations, reducing overall system cost while preserving location capability
3Device complexity
If communication link delay is not compensated, then system simplicity is maintained, but measurement precision deteriorates
Solution Approach 1:
The patent applies preliminary action by measuring and storing the communication link delay between each receiving station and the central station before performing TDOA calculations. This pre-measured delay information is then used to compensate for transmission delays in the actual location calculations, improving measurement precision without significantly increasing system complexity
Solution Approach 2:
The patent implements feedback by using the measured communication link delays to adjust and correct the TDOA calculations. The system continuously monitors and compensates for transmission delays using the pre-measured delay values, thereby improving measurement precision while maintaining relative system simplicity through a straightforward compensation mechanism
Data Source
AI summary
A method of locating a transmitter is disclosed. A communications link is established between multiple receiving stations and a control station, and used with a calibration signal to calibrate out the time delay of the communications link. A radiated signal from an unknown transmitter is received at a receiving station and sent to the control station over the communications link. The time of arrival is recorded. Upon receiving a user input, the communication link switches from transmitting the received radiated signal to transmitting the calibration signal. The start of calibration signal is timed to begin at the same time across all of the receiving stations. The communication link time delay for each link is calculated by subtracting the start time from the received time, and the communication link time delay is subtracted from the received time recorded for the radiated signal. TDOA calculations are made to locate the transmitter.