Accession Number:

ADD014645

Title:

Collision Detection System.

Descriptive Note:

Patent, Filed 26 Jun 89, patented 21 Aug 90,

Corporate Author:

DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s):

• Cope, Randall D.
• Egan, Mark P.

Report Date:

1990-08-21

Pagination or Media Count:

11.0

Abstract:

The detection, by doppler frequencies in reflected wave energy, of an object, such as an obstruction on a landing surface approached along a path at a shallow angle to the surface, using doppler frequencies returned from a fixed range. The frequencies returned by the surface and the obstruction are distinguished by their relation to a threshold frequency determined by the velocity along the path and the angle. Returns from the surface as the angle of incidence at the fixed range increases from the initial normal angle of incidence are minimized by selection of the carrier frequency, and clutter is rejected by ignoring a return at the fixed range that does not correspond to a subsequent return at a nearer range. Patents. jhd

Descriptors:

• *PATENTS
• *COLLISION AVOIDANCE
• *RADAR
• ANGLE OF INCIDENCE
• CARRIER FREQUENCIES
• COLLISIONS
• DETECTION
• DETECTORS
• DOPPLER EFFECT
• ENERGY
• REFLECTION
• SURFACES
• THRESHOLD EFFECTS
• WAVES
• LOW ANGLES
• RUNWAYS

Subject Categories:

• Active and Passive Radar Detection and Equipment
• Air Navigation and Guidance

Distribution Statement:

APPROVED FOR PUBLIC RELEASE