Multi-ship coherent geolocation system
First Claim
1. A method for improving the accuracy of a coherent time-of-arrival geolocation system in ascertaining the location of a pulse train emitter, comprising the steps of:
- providing multiple spaced-apart collectors at known locations so as to establish a long measurement baseline;
at each collector, measuring times of arrival of pulses emitted by the pulse train emitter using non-snippet based coherent time-of-arrival processing over tens of seconds to correlate received pulses at different collectors with associated emitted pulses such that only one received pulse need be correlated with the corresponding emitted pulse to obtain geolocation information based on time of arrival of other pulses at other collectors, thereby to remove any requirement of simultaneous collection of the same pulse at multiple collection platforms; and
,from an ensemble of measured times of arrival deriving the location of the emitter.
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Abstract
A system is provided for rapidly ascertaining the position of a pulse train emitter such as a radar using multiple collectors without requiring more than one platform to measure the same pulse. Thus time-of-arrival measurements at a number of collecting platforms are performed, with the positions of the platforms being accurately ascertainable using GPS data, and with time synchronization between the spaced-apart collectors performed by utilizing atomic clocks. In the multi-ship case, geolocation can be performed on ten milliseconds of data as opposed to 30 seconds of data for measurements involving a single platform. The subject system is preferable to conventional time-difference-of-arrival geolocation systems because those systems require that each of the collecting platforms measure the same pulse from the emitter, which severely constrains the flight paths of the collectors, limits the amount of usable data, and increases the system'"'"'s sensitivity requirements.
46 Citations
23 Claims
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1. A method for improving the accuracy of a coherent time-of-arrival geolocation system in ascertaining the location of a pulse train emitter, comprising the steps of:
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providing multiple spaced-apart collectors at known locations so as to establish a long measurement baseline; at each collector, measuring times of arrival of pulses emitted by the pulse train emitter using non-snippet based coherent time-of-arrival processing over tens of seconds to correlate received pulses at different collectors with associated emitted pulses such that only one received pulse need be correlated with the corresponding emitted pulse to obtain geolocation information based on time of arrival of other pulses at other collectors, thereby to remove any requirement of simultaneous collection of the same pulse at multiple collection platforms; and
,from an ensemble of measured times of arrival deriving the location of the emitter. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A system for improving the accuracy of a coherent time-of-arrival geolocation system in ascertaining the location of a pulse train emitter, comprising:
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multiple spaced-apart collectors at known locations so as to establish a long measurement baseline; a receiver at each of said collectors for measuring times of arrival of pulses emitted by the pulse train emitter using coherent time-of-arrival processing; and
,a processor using coherent processing in which the same emitted pulse need not be simultaneously received at said spaced-apart collectors for deriving the location of the emitter from an ensemble of measured times of arrival. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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Specification