John D Webb

US Patent:

40386562, Jul 26, 1977

Filed:

Mar 27, 1974

Appl. No.:

5/456574

Inventors:

John G. Webb - Sandia Park NM
Roger M. Gray - Dallas TX

Assignee:

The United States of America as represented by the Secretary of the Air
Force - Washington DC

International Classification:

G01S 702

US Classification:

343 5SA

Abstract:

A helicopter discrimination apparatus for a radar utilizing doppler filtering to discriminate between a missile and ground clutter. The short duration of the doppler filter pulses which are emitted by helicopter rotor blades are processed to prevent false alarms, thus allowing the radar-protected helicopter to operate in formation with other helicopters while maintaining protection against infra-red-seeking missiles.

US Patent:

44471513, May 8, 1984

Filed:

Jun 18, 1981

Appl. No.:

6/274917

Inventors:

Edward J. McLellan - Los Alamos NM
John A. Webb - Albuquerque NM

Assignee:

The United States of America as represented by the Department of Energy - Washington DC

International Classification:

G01J 142
H01J 4000

US Classification:

356218

Abstract:

The method and device of the instant invention is a detector of pulsed laser radiation which utilizes the electromotive force generated by the plasma formed when such radiation is focused onto a surface (1). Measurements are made with a 10. 6. mu. m CO. sub. 2 laser capable of producing peak intensities of 10. sup. 13 W/cm. sup. 2 when directed through a converging lens (2). Evacuated detector response to such laser intensity is 1 kV signal peak amplitude and subnanosecond risetimes into a 50. OMEGA. load (3). Detector performance is found to be greatly altered with the introduction of a background gas (4). For example, with one atmosphere of air, the detector produces prompt signals of the order of 1 V with subnanosecond response for pulse trains lasting 100 ns. With argon, krypton, or zenon at pressures of the order of 10 torr, the detector generates "trigger pulses" of about 250 V amplitude and 0. 2 ns risetimes.