Radar display apparatus
First Claim
1. Radar display apparatus for an azimuth scanning radar comprising a radar video digitiser;
- electronic digital storage means having a storage location for each of a predetermined number of cells forming between them a T.V. type radar display picture;
storage control means for converting the range/azimuth angle coordinates of the received digitised radar video into Cartesian coordinates for identifying the store locations of the corresponding cells in the storage means and for modifying data in the identified locations of said storage means so that the digital data in each said cell location is representative of the degree of positive correlation of digital video returns occurring in the respective cell on successive radar azimuth scans;
T.V. type visual display means; and
display control means arranged to read said digital data from the storage means and to control said display means to provide a substantially real time radar display picture composed of said cells with the brightness or color of each cell being representative of said degree of positive correlation,wherein said storage control means has locations for cells in a rectangular matrix for said T.V. display, andwherein the range/azimuth angle (r, θ
) co-ordinates are expressed digitally with unit range increments defining a range scan at each of successive azimuth increments and said store control means includes cell correlations means arranged to identify when successive range increments of a range scan in (r, θ
) co-ordinates convert to the same Cartesian co-ordinates and then to effect said modification of data in the respective cell location of the storage means only once in the range scan.
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Accused Products
Abstract
Radar display apparatus employs digital techniques to convert range/azimuth scan to T.V. scan. A digital store contains data defining the brightness of levels for the picture cells of a T.V. display. The store is continuously updated in accordance with received video from a digitiser. The correct cell in the store for updating is identified by converting polar coordinates to Cartesian coordinates in a Sin θ, Cos θ generator and integrators. The contents of the store for the addressed picture cell is modified by a control unit in accordance with the digitised video return so as to represent the degree of positive correlation of returns in that cell on successive azimuth scans of the radar. Thus the brightness or color of the cell on the T.V. display represents this degree of correlation.
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Citations
21 Claims
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1. Radar display apparatus for an azimuth scanning radar comprising a radar video digitiser;
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electronic digital storage means having a storage location for each of a predetermined number of cells forming between them a T.V. type radar display picture; storage control means for converting the range/azimuth angle coordinates of the received digitised radar video into Cartesian coordinates for identifying the store locations of the corresponding cells in the storage means and for modifying data in the identified locations of said storage means so that the digital data in each said cell location is representative of the degree of positive correlation of digital video returns occurring in the respective cell on successive radar azimuth scans; T.V. type visual display means; and display control means arranged to read said digital data from the storage means and to control said display means to provide a substantially real time radar display picture composed of said cells with the brightness or color of each cell being representative of said degree of positive correlation, wherein said storage control means has locations for cells in a rectangular matrix for said T.V. display, and wherein the range/azimuth angle (r, θ
) co-ordinates are expressed digitally with unit range increments defining a range scan at each of successive azimuth increments and said store control means includes cell correlations means arranged to identify when successive range increments of a range scan in (r, θ
) co-ordinates convert to the same Cartesian co-ordinates and then to effect said modification of data in the respective cell location of the storage means only once in the range scan. - View Dependent Claims (2, 3, 4, 20, 21)
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5. Radar display apparatus for an azimuth scanning radar comprising a radar video digitiser;
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electronic digital storage means having a storage location for each of a predetermined number of cells forming between them a T.V. type radar display picture; storage control means for converting the range/azimuth angle coordinates of the received digitised radar video into Cartesian coordinates for identifying the store locations of the corresponding cells in the storage means and for modifying data in the identified locations of said storage means so that the digital data in each said cell location is representative of the degree of positive correlations of digital video returns occurring in the respective cell on successive radar azimuth scans; T.V. type visual display means; and display control means arranged to read said digital data from the storage means and to control said display means to provide a substantially real time radar display picture composed of said cells with the brightness of color of each cell being representative of said degree of positive correlation, wherein the radar video digitiser provides a one bit digital video signal with a logic "0" indicating no video and a logic "1" indicating a positive video return. - View Dependent Claims (6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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Specification