Method for determining the optimum observer heading change in bearings-only passive emitter tracking

A method of uniquely identifying an emitter platform and mission utilizing an observer maneuver, comprising:

• measuring an emitter signal frequency, time and phase characteristics, wherein the emitter is on the target;
• generating from the emitter signal frequency, time, and phase characteristic measurements a set of parameters characterizing a set of potential emitter signal sources;
• identifying, from the set of potential emitter characterization and an emitter-platform association data base, a most probable set of platforms the emitter is on and associating the mode of operation of the emitter and the corresponding platform set with a set of emitter kinematic regimes, and
• utilizing a performance data base, deriving from the set of emitter kinematic regimes a specific speed or discrete set of speeds best adapted to a set of all possible platform missions, generating from the measured emitter signal frequency, time, and phase characteristics one or more emitter bearings, estimating from the one or more emitter bearings the emitter speed as a continuous function of emitter range, and determining the emitter ranges consistent therewith by comparing the continuous emitter speed with the specific speed or the discrete set of speeds derived from the performance data base;
• and
• identifying the emitter platform and mission as the mode, platform, and mission set associated with the correct a priori ranges, speeds and heading.

A method for assigning likelihood values, or relative probabilities to the identity of an emitter platform and the emitter mission utilizing an observer maneuver, comprising:

• measuring an emitter signal frequency, time and phase characteristics, wherein the emitter is on the target;
• generating from the emitter signal frequency, time, and phase characteristic measurements a set of parameters characterizing a set of potential emitter signal sources;
• identifying, from the set of potential emitter characterization and an emitter-platform association data base, a most probable set of platforms the emitter is on and associating the mode of operation of the emitter and the corresponding platform set with a set of emitter kinematic regimes, and
• utilizing a performance data base, deriving from the set of emitter kinematic regimes a specific speed or discrete set of speeds best adapted to a set of all possible platform missions, generating from the measured emitter signal frequency, time, and phase characteristics one or more emitter bearings, estimating from the one or more emitter bearings 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 specific speed or the discrete set of speeds derived from the performance data base;
• and
• assigning an accuracy figure of merit to the range estimate, speed estimate and heading estimate, wherein the accuracy figure of merit is determined from the predicted variance in the particular discrete speed estimate and the continuous speed function utilizing the accuracy figure of merit to determine an a priori estimator error variance corresponding to the range, speed and heading estimates used to determine the a priori state elements of the estimator, wherein each of the error variance and state pairs are used to initialize an estimator;
• utilizing the set of accuracy figure of merits and corresponding range, speed and heading estimates, to determine the best maneuver to undertake to satisfy the estimator observability requirement and the observer tactical needs;
• identifying the correct a priori estimate set based on bearing measurements made after the observer performs the maneuver;
• determining the correct estimator based on the a priori estimate identification;
• utilizing the estimator operating based on bearing measurements made before and after the maneuver to refine the emitter track;
• utilizing the emitter track estimate to predict a bearing to the emitter at the bearing measurement time;
• comparing the predicted and measured bearings;
• determining the need for subsequent maneuvers based on the comparison;
• and
• determining the need for the estimator operating based on further bearing measurements based on the comparison, wherein the mode, platform, and mission set associated with an priori range is assigned the likelihood value of the associated target motion analysis.

A method of estimating emitter range and heading from bearing measurements enhancing bearings-only estimator convergence to an emitter track, and permitting optimization of an observer position relative to the emitter at the end of the total bearing measurement period, by using one or more estimates of the emitter range, speed and heading, made from bearing measurements before an observer maneuver, to determine a most appropriate observer maneuver giving complete bearings-only target-motion-analysis observability, comprising the steps of:

• measuring one or more emitter characteristics;
• generating based on the emitter characteristic measurements a set of parameters characterizing a set of potential emitter signal sources;
• identifying, based on the set of potential emitter characterization parameters and an emitter data base, a most probable set of emitter and associating the mode of operation of the emitter and the corresponding emitter set with a set of emitter kinematic regimes, and
• utilizing a performance data base, deriving from the set of emitter kinematic regimes a specific speed or discrete set of speeds best adapted to a set of all possible emitter missions, generating from the emitter characteristic measurements one or more emitter bearings, estimating from the one or more emitter bearings 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 specific speed or the discrete set of speeds derived from the performance data base.

A computer-readable medium comprising:

• a data structure for an emitter 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:
• generate, based on emitter characteristic measurements, a set of parameters characterizing a set of potential emitter signal sources;
• identify, based on the set of potential emitter characterization parameters and the emitter data base, a most probable set of emitters and associating the mode of operation of the emitter and the corresponding emitter set with a set of emitter kinematic regimes, and
• utilize a performance data base to:
• (1) derive from the set of emitter kinematic regimes a specific speed or discrete set of speeds best adapted to a set of all possible emitter missions, (2) generate from the emitter characteristic measurements one or more emitter bearings, (3) estimate from the one or more emitter bearings 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 specific speed or the discrete set of speeds derived from the performance data base.