US 5,353,030 AGranted

Method for simulating high resolution synthetic aperture radar imagery from high altitude photographs

AssigneeScience Applications International Corporation

InventorsRobert D. Koch, Harold W. Dean, Roger L. Overdorf

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Abstract

A simple and inexpensive method for using aerial or satellite photographs of an area of terrain to form images to be used in the simulation of a series of synthetic aperture radar (SAR) images of the terrain as would be observed by a down-looking SAR mounted on an aircraft over the terrain. Scanned and digitized photographic pixels are formed and converted into radar image pixels and combined into composite images as required for SAR simulation. Terrain elevation data are assembled, correlated with the radar image pixels and converted to elevation images. These images are stored on media accessible by aircraft simulators and correlated with simulated aircraft position and altitude data to form composite images with obscured terrain features for display as darkened areas closely duplicating actual SAR images when displayed in an aircraft simulator.

Claims9

Dependent claims

A method of using photographs of a designated area, characterized by varying gray levels, to develop radar-like images for forming a simulated synthetic aperture radar (SAR) image of the designated area of terrain as would be obtained by a SAR carried by a host aircraft, comprising:

(a) scanning and digitizing the photographs to form a digitized photographic image (DPI) representing the designated area, the DPI comprising a set of minimal resolution picture elements (pixels) each pixel having an associated gray level related to a corresponding terrain feature optical reflectivity;
(b) from the DPI pixels, creating a simulated digitized radar image (SDRI) comprising a set of corresponding SDRI pixels and establishing for each SDRI pixel a gray level which represents a radar reflectivity of the terrain feature in place of the optical reflectivity represented by the DPI pixels;
(c) determining and assigning a terrain elevation value to each pixel in the SDRI as correlated terrain elevation data and forming an image therefrom;
and
(d) creating a terrain data set (TDS) by storing the SDRIs and correlated terrain elevation data image on a medium for subsequent access by an aircraft simulator.

2 more elements

Dependencies are inferred from the claim text.