초록 ▼

A method and system for determining the geolocation--i.e., the latitude, longitude, and altitude--of a stationary RF signal emitter from two or more moving observer aircraft. The observers receive signals from the emitter and the system measures the phase difference between the signals. The observer

A method and system for determining the geolocation--i.e., the latitude, longitude, and altitude--of a stationary RF signal emitter from two or more moving observer aircraft. The observers receive signals from the emitter and the system measures the phase difference between the signals. The observers then perform pulse time of arrival (TOA) measurements over a predetermined clock interval, and calculate the time difference of arrival (TDOA) of corresponding, same-pulse, emitter signals. Based on geometric relationships, the system creates a series of circular lines of position (LOPs) for each observer, and computes hyperbolic LOPs based on the TDOA calculations. The system determines emitter location from the intersection of the hyperbolic LOPs and the circular LOPs.

대표청구항 ▼

[ What is claimed is:] [1.] A method for determining the geolocation of a stationary emitter using at least a first and a second moving observer, the method comprising the steps of:receiving first and second emitter signals, respectively, at the first and second moving observers;measuring the ambigu

[ What is claimed is:] [1.] A method for determining the geolocation of a stationary emitter using at least a first and a second moving observer, the method comprising the steps of:receiving first and second emitter signals, respectively, at the first and second moving observers;measuring the ambiguous phase difference between the first and second signals at corresponding update intervals;estimating the greatest and least possible integer value of the ambiguous phase difference, the integer values comprising a set of possible ambiguity integers;performing pulse time-of-arrival (TOA) measurements of the emitter signal received by the observers over a predetermined clock interval;using the TOA measurements performed by the observers to calculate the time-difference-of-arrival (TDOA) of corresponding, same-pulse, emitter signals;generating a family of circular lines of position (LOPs) for each observer based on the ambiguous phase differences measured and the integer values estimated, wherein with no measurement error the emitter would lie on exactly one of the circular LOPs associated with each observer;computing hyperbolic LOPs based on the TDOA calculations; anddetermining emitter location utilizing the intersection of the hyperbolic LOPs generated from the TDOA measurement, and circular LOP data.