Method of passively estimating an emitter's position and velocity using bearings-only without requiring observer acceleration

An apparatus for estimating target range and heading from bearing measurement without requiring observer heading change or observer acceleration during the bearing measurement collection period, comprising:

• measuring means for measuring an emitter signal frequency, time and phase characteristics;
• generating means for generating from the measurements a set of parameters characterizing a specific emitter as a signal source;
• identifying means for identifying, based on the emitter characterization parameters and an emitter-platform association data base, the most probable platform including the emitter and associating the mode of operation of the emitter and the corresponding specific platform with a particular kinematic regime;
• deriving means for utilizing a performance data base to derive from the kinematic regime a speed best adapted to the platform's mission, generating from the measured emitter characteristics the emitter bearings, estimating from emitter bearings the emitter speed as a continuous function of emitter range, and determining, by comparing the continuous emitter speed with the performance data base derived speed, the emitter range consistent therewith;
• and
• assigning means for assigning an accuracy figure of merit to the range estimate, where the accuracy is determined based on the predicted variance in the discrete speed estimate and the continuous speed function.

A method of estimating target range and heading from bearing measurements without requiring observer heading change or observer acceleration during the bearing measurement collection period, comprising the steps of:

• measuring an emitter signal frequency, time and phase characteristics;
• generating from the measurement a set of parameters characterizing a specific emitter as a signal source;
• identifying, from the emitter characterization and an emitter-platform association data base, a most probable platform including the emitter and then associating the mode of operation of the emitter and the corresponding specific platform with a particular kinematic regime, and
• utilizing a performance data base to derive from the kinematic regime a speed best adapted to the platform's mission, and generating from the measured emitter characteristics the emitter bearings, estimating from emitter bearings the emitter speed as a continuous function of emitter range, and determining, by comparing the continuous emitter speed with the performance data base derived speed, the emitter range consistent therewith;
• and
• assigning an accuracy figure of merit to the range estimate, where the accuracy is determined from the predicted variance in the discrete speed estimate, and the continuous speed function,
• wherein generating bearings and producing an emitter elevation angle and an azimuth angle, and wherein the discrete speed ambiguity is reduced, resulting in a unique range estimate, by utilizing the elevation angle and determined discrete range to estimate the emitter platform's altitude, comparing the estimated altitude with the altitude associated with the discrete speed in the performance data base and accepting the range estimate only if the estimated altitude and database altitude are consistent.

A method of estimating target range and heading from bearing measurements without requiring observer heading change or observer acceleration during the bearing measurement collection period, comprising the steps of:

• measuring an emitter signal having characteristics;
• generating based on the emitter signal measurement a set of parameters characterizing a specific emitter as a signal source;
• identifying, based on the generated emitter parameter characterization and an emitter-platform association data base, a most probable platform including the emitter and associating the mode of operation of the emitter and the corresponding specific platform with a particular kinematic regime;
• and
• utilizing a performance data base, deriving from the kinematic regime one or more speed best adapted to the platform mission and generating from the emitter signal measurement the emitter bearing, estimating from the emitter bearing the emitter speed as a continuous function of emitter range, and determining the emitter range consistent therewith by comparing the continuous emitter speed with the one or more speed derived from the performance data base.

A computer-readable medium comprising:

• a data structure for an emitter-platform association data base;
• a data structure for a performance data base;
• at least one sequence of machine executable instructions in machine form, wherein execution of the instructions by a processor cause the processor to:
• determine characteristics of a measured emitter signal;
• generate a set of parameters characterizing a specific emitter as a signal source based on the determined characteristics;
• identify a most probable platform including the emitter based on the generated parameters and the emitter-platform association data base and associate the emitter operating mode and the corresponding specific platform with a particular kinematic regime;
• and
• utilize the performance data base to (1) derive based on the kinematic regime one or more speed values best adapted to the platform mission, (2) generate based on the emitter signal measurement the emitter bearing, (3) estimate from the emitter bearing the emitter speed as a continuous function of emitter range, and (4) determine the emitter range consistent therewith by comparing the continuous emitter speed with the one or more speed values derived from the performance data base.