Patents by Inventor Marvin S. Kefer

Marvin S. Kefer has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4942404
    Abstract: A passive doppler differential ranging method for use with respect to an aircraft radar for determining the range, R, of a threat passively, includes the steps of mounting a first receiving antenna and a second receiving antenna on an aircraft and positioning the first and second antennas a known distance, d, apart from each other, and determining the azimuth angle .alpha. of the threat with respect to the aircraft at a first time t.sub.o. A first differential doppler phase shift, .DELTA..phi., between the first and second antennas of a received signal transmitted by the threat at time t.sub.o is then determined. The velocity of the aircraft is measured, and a second differential phase shift, .DELTA..phi..sub.1, between the first and second antennas of a received signal transmitted by the threat at time t.sub.1 is then determined. The differential differential doppler phase shift, .DELTA..DELTA..phi.
    Type: Grant
    Filed: July 18, 1989
    Date of Patent: July 17, 1990
    Assignee: AIL Systems, Inc.
    Inventor: Marvin S. Kefer