US 2016/0103214 A1Published application

Use of Range-Rate Measurements in a Fusion Tracking System via Projections

AssigneeSRC, Inc.

InventorsBarry L. Clark, Andrew D. Keckler, Thomas A. Houman

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Abstract

A target is located and a track is associated with the target in the fusion coordinate system. An estimate/prediction of the target's velocity is developed within the tracker, as well as {right arrow over (T)}, a vector representing the distance from the fusion center to the target as estimated by the tracker, and {right arrow over (S)}, a vector representing the known distance from the fusion center to the sensor. The sensor's range vector, {right arrow over (R)} (the distance from the sensor to the target as predicted by the tracker) is transformed to fusion coordinates. Using the sensor's range vector, normalized to unit length, in fusion coordinates and the estimated target's velocity, an estimate of the target's speed projected in the direction of {right arrow over (R)} is derived. The estimated range-rate is compared per update to the sensor's measured range-rate in the form of an error measurement. The error is then used to correct the track's velocity prediction.

Claims20

Dependent claims

A method comprising the steps of:

providing a system comprising a plurality of radars each configured to obtain sensor data for at least one target, and a processor in communication with the plurality of radars, wherein the processor comprises a tracking filter;
obtaining, with the plurality of radars, sensor data regarding the target, wherein the sensor data comprises a range-rate measurement;
transmitting the obtained sensor data to the processor;
generating, by the processor utilizing a pulse-repetition interval of the system, a range hypothesis and a range-rate hypothesis for the target;
converting, by the processor, at least some of the obtained sensor data from the plurality of radars to a common coordinate system;
predicting, by the tracking filter using the obtained sensor data, a first track state for the target, wherein said prediction comprises an estimate of a position of the target and an estimate of a velocity of the target;
determining, by the processor, a distance to the target from each radar of the plurality of radars to obtain a first estimated position with respect to each radar of the plurality of radars;
determining, by the processor using the determined distances, an estimate of a velocity of the target in the direction of each radar of the plurality of radars;
determining an error measurement by comparing the estimated velocity in the direction of each radar of the plurality of radars to the range-rate hypothesis for the target;
and
updating the predicted first track state with the determined error measurement to generate a second track state for the target.

8 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/878,558Filed 8 Oct 2015
Priority: 8 Oct 2014
Published: 14 Apr 2016
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

G01S 13/42
Systems determining position data of a target: simultaneous measurement of distance and other co-ordinates
G01S 13/58
Systems of measurement based on relative movement of target: velocity or trajectory determination systems; Sense-of-movement determination systems
G01S 13/723
For two-dimensional [2D] tracking, e.g. combination of angle and range tracking, track-while-scan radar: by using numerical data
G01S 13/87
Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose…:…