Litton Systems, Inc.

Northrop Grumman Systems Corporation

Fred W Erickson

Yair Alon

William F Smith

Garth Ernest Weals

Ray C Pizzuti

John B Rodwig

Roy Hiroshi Nakahara

An exemplary radar system includes a waveform generator that generates a control waveform. An in-phase and quadrature modulator receives the control waveform from the waveform generator and in turn generates a waveform output that is amplified by a power amplifier before being transmitted from an antenna.

Radar based application programmable waveform generator component

The Radar Scan Converter receives range and azimuth data that is generated by a conventional radar and presented in a polar coordinate system, and processes and displays this data, in real time, on a conventional generally rectangular display screen which has a display formed by a relatively large number of pixels organized in the X- and Y-axes of a Cartesian coordinate system. The Radar Scan Converter sequentially updates each pixel in the display by (1) selecting a pixel address in the Cartesian coordinate system, (2) determining the corresponding cell address in a direct display memory interface, (3) reading the video level in this corresponding cell, (4) then responsive to this respective video level, either initially loading or subsequently updating the associated pixel in a screen image memory, and (5) refreshing the display from the screen image memory through respective cycles over repeated radar scans. The Radar Scan Converter System displays shades of gray or color, which may represent one or more video levels. It also has an image decay capability over repeated radar scans through its preferred use of initially rotating video stored in the screen image memory and subsequently unrotating it by an increasing value during the display refresh cycles.

Radar scan converter with direct display memory interface

The Radar Scan Converter System (1) receives range and azimuth data generated by a conventional radar as presented in a polar coordinate system, (2) stores this data in associated cell locations in a range/azimuth polar video map, and (3) displays this polar coordinate range/azimuth data in a Cartesian coordinate system, in real time, on a conventional computer monitor having a rectangular display formed by a relatively large number of pixels organized in the Cartesian coordinate system. Each pixel in the display is sequentially update by (1) selecting a respective pixel address, (2) determining the corresponding range/azimuth cell address in the polar video map, (3) reading the video level in this corresponding range/azimuth cell, and (4) in response to this associated video level, either initially loading or subsequently updating the selected pixel. The radar scan converter system displays (1) shades of gray or color, which may represent one or more video levels, and (2) has an image decay capability over repeated radar scans which is particularly suited for display of a moving target.

Radar scan converter system

A constant current drive circuit that can be driven directly from the output of a shift register which can find use, for example, as a constant current source for a light emitting diode (LED) to ensure uniform birghtness throughout a display surface that includes a plurality of LEDs.

Drive circuit with constant current output

A constant current drive circuit that can be driven directly from the output of a shift register which can find use, for example, in maintaining a constant current through a controlled device such as one or more light emitting diodes (LEDs) to ensure uniform brightness throughout a display surface that includes a plurality of LEDs.

Growing community of inventors

Agoura Hills, CA, United States of America

Fred W Erickson