US4220967A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Scene tracker using multiple independent correlators
Assignee: Raytheon Co
•
Filing: 1976-09-27
•
Granted: 1980-09-02
•
Expires: 1996-09-27
Abstract
Abstract A scene tracker for use with imaging or quasi-imaging sensors such as TV cameras, FLIRS, millimeter-wave scanners, or the like is disclosed. Specifically, the invention is concerned with a form of correlation tracking. At the start of a track mode, part or parts of a scene are stored in a memory. Every subsequent video scan is then compared with the scene or parts of the scene stored in memory to find the "best match" between live data and stored data. This process generates signal output proportional to horizontal and/or vertical translations of the scene. Besides pure translation, the disclosed scene tracker is capable of tracking an original aim point in the presence of scene rotation, scene growth (zooming), scene reduction (dezooming), distortion, and/or partial scene obscuration. Special novel features of the invention include a multi-cell correlation principle; a novel method of computing and storing correlation functions for each cell; a method to derive weighted average displacements for the entities of all cell correlations; and a novel video signal processing technique.
Inventors
- 👤 LeRoy F. Ichida
- 👤 Robert A. Sturla
- 👤 Jacob M. Sacks
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 07:12
CPC Classifications
G; G01; G01S; G01S3/00; G01S3/78; G01S3/782; G01S3/785; G01S3/786; G01S3/7864; G01S3/7865
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
195 words
A scene tracker system adapted for responding to sequentially applied fields of data each of which are definitive of a scene within a field of view, so as to provide global correlation coordinate signals which are indicative of the relative spatial displacement between scenes defined by different fields of data, said system comprising: reference date storage means for storing reference cell data from a preselected plurality of portions of one field of data; means for correlating the data for each reference cell against data for an associated search cell, with the data for each associated search cell being derived from a portion of a subsequent field of data which encompasses the relative position of the associated reference cell; and for providing local correlation coordinate signals indicative of the relative location within each search cell of the correlation match between each search cell and its respective reference cell; and processor means for processing said plurality of local correlation coordinate signals so as to produce as a function thereof global correlation coordinate signals which are indicative of the relative spatial displacement between the scenes defined by said one field of data and said subsequent field of data.
Claim 2
Dependent Claim
195 words
A scene tracker system adapted for responding to sequentially applied fields of data each of which are definitive of a scene within a field of view, so as to provide global correlation coordinate signals which are indicative of the relative spatial displacement between scenes defined by different fields of data, said system comprising: reference date storage means for storing reference cell data from a preselected plurality of portions of one field of data; means for correlating the data for each reference cell against data for an associated search cell, with the data for each associated search cell being derived from a portion of a subsequent field of data which encompasses the relative position of the associated reference cell; and for providing local correlation coordinate signals indicative of the relative location within each search cell of the correlation match between each search cell and its respective reference cell; and processor means for processing said plurality of local correlation coordinate signals so as to produce as a function thereof global correlation coordinate signals which are indicative of the relative spatial displacement between the scenes defined by said one field of data and said subsequent field of data.
Claim 3
Dependent Claim
19 words
The system of claim 1 wherein said reference data storage means comprises a plurality of random access memory devices.
Claim 4
Dependent Claim
102 words
The system of claim 1 wherein said means for correlating, receives reference cell data signals from said reference data storage means for correlating with video signals from the currently applied field of data, said means for correlating comprising: a multiplicity of Exclusive NOR circuits, each receiving video signals from the currently applied field of data and a reference cell data signal; a plurality of read-only memory devices, each responsive to signal output from a predetermined number of said Exclusive NOR circuits; and a plurality of digital adders responsive to output signals from said read-only memory devices and developing therefrom a correlation function.
Claim 5
Dependent Claim
16 words
The system of claim 1 wherein said means for correlating includes a stored-program central processing unit.
Claim 6
Dependent Claim
59 words
The system of claim 1 further comprising means for detecting correlation matches which are indicative of greater than a preselected degree of correlation and for excluding from use in the production of said global correlation coordinate signals, local correlation coordinate signals derived from respective search cells in which multiple correlation matches of greater than said preselected degree are detected.
Claim 7
Dependent Claim
31 words
The system of claim 5 further comprising means for updating the reference cell data associated with respective search cells having multiple correlation matches of greater than said preselected degree of correlation.
Claim 8
Dependent Claim
36 words
The system of claim 1 further comprising a self-thresholding video processor for digitizing said sequentially applied fields of data prior to their being processed by said reference data storage means and by said means for correlating.
Claim 9
Dependent Claim
82 words
The system of claim 7 wherein said self-thresholding video processor comprises: buffer means for receiving and buffeting video signals which comprise said fields of data bandpass filter means for receiving and bandpass filtering said buffered video signals from said buffer means; delay network means for receiving and delaying said bandpass filtered video signals from said bandpass filter means; and comparator means for receiving and comparing delayed video signals from said delay network means with undelayed video signals from said bandpass filter means.
Claim 10
Dependent Claim
16 words
The system of claim 8 wherein said bandpass filter means is a three-pole Bessel bandpass filter.
Claim 11
Dependent Claim
66 words
The system of claim 7 wherein said self-thresholding video processor includes a zero threshold processor which comprises: bandpass filter means for receiving and bandpass filtering video signals which comprise said fields of data; shorted delay line means for quasi differentiating said bandpass filtered video signals; and comparator means for receiving the bandpass filtered and quasi differentiated video signals and comparing them with a reference input signal.
Claim 12
Dependent Claim
16 words
The system of claim 7 wherein said bandpass filter means in a three-pole Bessel bandpass filter.
References Cited (Backward Citations)
US3805261A
Cited
US3794272A
Cited
US3943277A
Cited
US4106726A
Cited
US3829614A
Cited
US3828122A
Cited
US4025718A
Cited
GB1533935A
Cited
GB1515295A
Cited
FR2339869A1
Cited
US4164728A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-09-02 | 1984-03-03 | 1984-09-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-02 | 1988-03-03 | 1988-09-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-02 | 1992-03-03 | 1992-09-02 | $7700.00 | Window Closed / Lapsed |