Two dimension radar system with selectable three dimension target data extraction
First Claim
1. A radar system for a selectable three dimension or two dimension position indication of targets within the surveillance volume comprising:
- an antenna adapted for selectively directing a fan beam and a narrow beam, wherein the narrow beam is scannable in elevation angle and has a narrower beamwidth in elevation angle than the fan beam;
a two dimension radar system coupled to the antenna for transmitting signals into the surveillance volume and for receiving reflected target signals from the antenna and for processing the reflected signals by means including at least one receiver for indicating the azimuth and range of the targets; and
an elevation angle measurement means coupled to the antenna and to the two dimension radar system for determining the elevation position of a selected target by selecting and sequentially lobing the narrow beam through a plurality of positions, and by receiving from the at least one receiver of the two dimension radar system reflected signals received from the selected target by the two dimension radar system during the scanning of the narrow beam and by processing those signals to indicate the elevation position of the selected target.
1 Assignment
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Accused Products
Abstract
A single two dimension radar system having the capability of developing two dimensional data on all targets in its surveillance volume and three dimensional data for selected targets in its surveillance volume is disclosed. A single phased array antenna having two selectable elevation beam patterns, a wide beam and a narrow beam, is rotated in azimuth. In the two dimension mode, targets are detected and tracked in an azimuth and range position through use of the wide elevation beam. Upon selecting a particular target in track for three dimension data extraction, the radar system changes to the three dimension mode prior to the azimuth position of the selected target, and performs a sequential lobing process of the narrow beam in elevation angle. The power ratios of the target returns in the sequential lobes are analyzed and an elevation position of the selected target is determined. The radar system reverts to the two dimension mode after leaving the azimuth position of the selected target.
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Citations
17 Claims
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1. A radar system for a selectable three dimension or two dimension position indication of targets within the surveillance volume comprising:
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an antenna adapted for selectively directing a fan beam and a narrow beam, wherein the narrow beam is scannable in elevation angle and has a narrower beamwidth in elevation angle than the fan beam; a two dimension radar system coupled to the antenna for transmitting signals into the surveillance volume and for receiving reflected target signals from the antenna and for processing the reflected signals by means including at least one receiver for indicating the azimuth and range of the targets; and an elevation angle measurement means coupled to the antenna and to the two dimension radar system for determining the elevation position of a selected target by selecting and sequentially lobing the narrow beam through a plurality of positions, and by receiving from the at least one receiver of the two dimension radar system reflected signals received from the selected target by the two dimension radar system during the scanning of the narrow beam and by processing those signals to indicate the elevation position of the selected target. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 12, 13, 14, 15)
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10. A radar system for a selectable three dimension or two dimension position indication of targets within the surveillance volume comprising:
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a planar phased array antenna adapted for selectively directing a fan beam and a narrow beam wherein the narrow beam is scannable in elevation angle and has a narrower beamwidth in elevation angle than the fam beam; a two dimension radar system coupled to the antenna for transmitting signals into the surveillance volume and for receiving reflected target signals from the antenna and for processing the reflected signals by means including at least one receiver for detecting and locating the position of the targets in terms of azimuth and range; and a processing means coupled to the antenna and to the two dimension radar system for determining the elevation position of selected targets by selecting the narrow beam at the azimuth position of a selected target, sequentially lobing the narrow beam in a plurality of selected overlapping elevation angle positions, receiving from the at least one receiver of the two dimension radar system reflected energy from the selected target received by the two dimension radar system in the overlapping elevation angle positions, comparing the reflected energy received at the different elevation angle positions, and determining the elevation position of the selected target thereby.
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11. A radar system for a selectable three dimension or two dimension position indication of targets within the surveillance volume comprising:
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a planar phased array antenna adapted for selectively directing a fan beam and a narrow beam wherein the narrow beam is scannable in elevation angle and has a narrower beamwidth in elevation angle than the fam beam; a two dimension radar system coupled to the antenna for transmitting signals into the surveillance volume and for receiving reflected target signals from the antenna and for processing the reflected signals for detecting and locating the position of the targets in terms of azimuth and range; a processing means coupled to the antenna and to the two dimension radar system for determining the elevation position of selected targets by selecting the narrow beam at the azimuth position of a selected target, scanning the narrow beam in a plurality of selected overlapping elevation angle positions, receiving from the two dimension radar system reflected energy from the selected target received by the two dimension radar system in the overlapping elevation angle positions, comparing the reflected energy received at the different elevation angle positions, and determining the elevation position of the selected target thereby; and wherein the processing means also collapses the reflected energy during the use of the narrow beam, and transmits the collapsed energy to the two dimension radar system whereby the two dimension radar system continues to detect and locate targets while the processing means determines the elevation position of the selected target.
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16. A radar system for a selectable three dimension or two dimension position indication of targets within the surveillance volume comprising:
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an antenna adapted for selectively directing a fan beam and a narrow beam, wherein the narrow beam is scannable in elevation angle and has a narrower beamwidth in elevation angle than the fan beam; a two dimension radar system coupled to the antenna for transmitting signals into the surveillance volume and for receiving reflected target signals from the antenna and for processing the reflected signals for indicating the azimuth and range of the targets; an elevation angle measurement means coupled to the antenna and to the two dimension radar system for determining the elevation position of a selected target by selecting and scanning the narrow beam, and by receiving from the two dimension radar system reflected signals received from the selected target by the two dimension radar system during the scanning of the narrow beam and by processing those signals to indicate the elevation position of the selected target; the elevation angle measurement means comprises a computing means responsive to programming residing therein for determining the elevation position of the selected target by; initiating the programming in response to a request therefor; determining an azimuth window about the selected target; controlling the antenna to select the narrow beam at the beginning of the azimuth window; scanning the narrow beam in a plurality of selected elevation positions while in the azimuth window; determining a range cell about the selected target; and resolving the selected target from the reflected signals received during use of the narrow beam; the computer means is further for collapsing the reflected signals received during use of the narrow beam to form two dimension target plots and correlating the target plots with the reflected signals received from the selected target during use of the narrow beam to resolve the selected target. - View Dependent Claims (17)
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Specification