Radar apparatus and method for enhancing the display of moving targets
First Claim
1. A method of processing radar returns received on a plurality of scans of a region, comprising the steps of:
- providing a scan-to-scan correlated image of radar returns from the region; and
displaying said image as a plurality of pixels wherein pixels corresponding to new radar returns without positive correlation on at least the immediately prior scan of the region are displayed with an enhanced characteristic and pixels displayed with said enhanced characteristic are displayed with a characteristic other than said enhanced characteristic on the next scan regardless of whether new radar returns are received.
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Accused Products
Abstract
A radar system that enhances the display of moving targets by using negative scan-to-scan correlation to determine which pixels will be displayed at the brightest level. More specifically, a bit image stores a multi-bit scan-to-scan correlated history for each pixel on a display screen, and when new video data is received on a scan, the bit image memory is modified in accordance therewith. A pixel is enhanced to the brightest level only if a return is received from a spacial location from which returns were not received on previous scans. Thus, a target that moves to a new location is displayed at the brightest level because it doesn'"'"'t correlate with returns from prior scans.
37 Citations
34 Claims
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1. A method of processing radar returns received on a plurality of scans of a region, comprising the steps of:
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providing a scan-to-scan correlated image of radar returns from the region; and displaying said image as a plurality of pixels wherein pixels corresponding to new radar returns without positive correlation on at least the immediately prior scan of the region are displayed with an enhanced characteristic and pixels displayed with said enhanced characteristic are displayed with a characteristic other than said enhanced characteristic on the next scan regardless of whether new radar returns are received. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method of processing radar returns from repeated scans of a region, comprising the steps of:
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digitizing said radar returns; scan converting said digitized radar returns into an x,y format of said region; correlating said digitized returns from scan-to-scan to develop a raster scan image formed by a plurality of x,y pixels each represented by a multi-bit value corresponding to correlation of radar returns received from the same spacial location on successive scans; transferring said image to a visual display and displaying at a brightest level those pixels which were off after the next to last scan and for which corresponding radar returns have been received on the last scan; and displaying at a level other than said brightest level those pixels which were displayed at the brightest level after the next to last scan regardless of whether radar returns were received on the last scan. - View Dependent Claims (8, 9)
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10. A method of processing echo signals, comprising the steps of:
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repeatedly scanning a predetermined region for echo signals reflected from objects within said predetermined region; providing a digital representation of each of said echo signals wherein each of said digital representations is arranged according to the spacial location of the object within the region from which the respective echo signal was reflected; spacially correlating said digital representations from scan-to-scan; and displaying said correlated digital representations wherein the display of digital representations without prior correlation are enhanced and enhanced digital representations are displayed without enhancement on the next scan regardless of whether echo signals are received.
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11. A method of processing echoes received from repeated scans of a region, comprising the steps of:
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providing a bit image in a memory having a plurality of multi-bit storage locations each corresponding to a pixel of a raster scan display wherein each of said multi-bit storage locations contains digitized video data corresponding to a history of echoes from a respective point in space; modifying said digitized video data to enhance the display of pixels that correspond to newly received echoes that are received from respective points in space from which echoes were not received on at least the most recent prior scan of said region; and modifying said digitized video data to display without enhancement those pixels that were displayed with enhancement on the last scan regardless of whether newly received echoes were received on the most recent scan.
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12. In a radar system having a memory storing a radar image used to raster scan a visual display wherein said radar image is representative of a history of returns from a plurality of scans of a region and is formed by pixels each of which is stored at a pixel location as a digital level corresponding to a brightness display level between off and bright with at least one intermediate level, a method comprising the steps of:
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detecting radar returns on a plurality of scans of said region; modifying said radar image in said memory by storing said bright digital level at pixel locations that were at said off level and for which respective radar returns have been detected on the most recent scan of said region; and modifying said radar image in said memory by storing said at least one intermediate level at pixel locations that were at said bright level on the last scan regardless of whether radar returns have been detected on the most recent scan of said region. - View Dependent Claims (13, 14, 15)
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16. Radar apparatus for azimuth scanning a region on a plurality of successive scans, comprising:
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a raster scan visual display; bit image memory means for providing digital data to raster scan said visual display, said memory means having a multi-bit storage location for each pixel on at least a portion of said raster scan display wherein each of said pixels is displayed at one of a plurality of different brightness levels; and means responsive to echo returns from objects in said region on a plurality of successive scans for developing a scan-to-scan correlated radar image of said region in said bit image memory, said developing means comprising means for providing digitized data to said memory means to provide a bright level display of each pixel that corresponds to an echo return from a respective spacial location from which an echo return was not received on a predetermined number of prior scans and to provide a display level other than said bright level on the last scan for each pixel that was displayed at said bright level regardless of corresponding echo returns on the most recent scan so as to enhance the display of moving objects in said region that have moved to new locations since the last scan. - View Dependent Claims (17, 18, 19, 20)
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21. Apparatus for processing radar returns received on a plurality of scans of a region, comprising:
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means for providing a scan-to-scan correlated image of radar returns from the region; and means for displaying said image as a plurality of pixels, said displaying means comprising means for enhancing with respect to all other pixels the display of pixels corresponding to new radar returns without positive correlation on a plurality of successive prior scans of the region. - View Dependent Claims (22, 23, 24, 25)
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26. Radar apparatus, comprising:
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means for repeatedly scanning a predetermined region for echo signals; means for digitizing said echo signals to provide digital data corresponding to echo signals reflected from objects at respective spacial locations within said predetermined region; means for scan-to-scan correlating said digital data according to spacial location; and means responsive to said correlating means for providing a visual image representative of objects in said predetermined region from which said echo signals are reflected, said displaying means comprising means for enhancing the representative display of an object that has moved to a new spacial location since the last scan and for diminishing the enhancement of such spacial location on the next scan regardless of whether echo signals are received.
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27. Radar apparatus, comprising:
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means for repeatedly scanning a predetermined region for echo signals from objects within said predetermined region; means for providing digital representations of said echo signals wherein each of said digital representations is arranged according to the spacial location of the respective object within said region from which the echo signal was reflected; means for spacially correlating said digital representations from scan-to-scan; and means for displaying said correlated digital representations wherein digital representations that do not correlate positively with digital representations from a predetermined number of scans are enhanced and enhanced digital representations are diminished on the next scan regardless of whether corresponding echo signals are received.
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28. Radar display apparatus for an azimuth scanning radar comprising:
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means for receiving echo signals from objects on sequential scans of a predetermined region; means responsive to said echo signals for providing digitized radar video; electronic digital storage means having a plurality of multi-bit storage location each corresponding to a predetermined pixel of an image of said predetermined region; means for modifying digital data stored in said electronic digital storage means in accordance with newly received digitized radar video so that the digital data in each of said multi-bit storage locations is representative of the degree of positive correlation of digitized radar video occurring at the respective pixels on successive radar azimuth scans; and means for displaying said digital data from said electronic digital storing means wherein pixels without positive correlation with previous scans are enhanced and enhanced pixels are displayed without enhancement on the next scan regardless of whether corresponding echo signals are received.
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29. Radar display apparatus for an azimuth scanning radar, comprising:
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a visual display; a bit image memory for providing raster scan video data to said visual display, said bit image memory having multi-bit storage locations for each pixel in a predetermined field of pixels on said display wherein each pixel can be displayed at different levels of brightness; and means for continuously modifying the digital data stored in said bit image memory in accordance with new digitized radar video received on the most recent scan so that the digital data in said memory is scan-to-scan correlated data for said field of pixels, said modifying means comprising means for enhancing the display of digital data for a pixel if a new digitized radar video return is received and there is no positive scan-to-scan correlation and for deemphasizing the display of an enhanced pixel on the next scan regardless of whether a new digitized radar video return is received.
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30. In a radar system having a memory storing a radar image used to raster scan a visual display wherein said radar image is representative of a history of returns from a plurality of scans of a region and is formed by pixels each of which is stored at a pixel location as a digital level corresponding to a display brightness level between off and bright with at least one intermediate brightness level, an apparatus comprising:
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means for detecting radar returns on a plurality of scans of said region; means responsive to said detecting means for modifying said radar image in said memory, said modifying means comprising means for storing said bright digital level at a pixel location which is at said off level and for which a radar return has been detected on the most recent scan of said region; and means for storing said at least one intermediate brightness level at a pixel location which is at said bright level and for which a corresponding radar return has been detected on the most recent scan of said region. - View Dependent Claims (31, 32, 33, 34)
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Specification