Collision detection system
US4951056A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 26, 1989 |
| Grant date | Aug 21, 1990 |
| Priority date | — |
| Expiry date | Jun 26, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S13/913
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The detection, by doppler frequencies in reflected wave energey, of an obt, 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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.