Doppler navigation system with enhanced multi-path discrimination capability
US4146894A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 4, 1977 |
| Grant date | Mar 27, 1979 |
| Priority date | — |
| Expiry date | Nov 4, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S1/40
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A radio navigation system of the simulated Doppler type, including a ground beacon having a multi-element linear antenna array, the elements of which are energized discretely and, in turn, to provide digitized scanning. A remote receiver, in an aircraft on landing approach, for example, derives a beat signal relating to a navigational angle. The remote receiver has a bandpass filter covering the range of Doppler beat frequencies of directly received signals and also detects the start of each ground beacon commutation cycle. A unique combination of inhibiting circuits for eliminating filter transients during at least part of its transient response time and filter cut-off characteristics affords discrimination between direct and multi-path signals when the angular separation of the paths of those signals is at a minimum.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.