Communications: directive radio wave systems and devices (e.g. – Determining distance – Altimeter
Reexamination Certificate
2005-12-20
2005-12-20
Hellner, Mark (Department: 3663)
Communications: directive radio wave systems and devices (e.g.,
Determining distance
Altimeter
Reexamination Certificate
active
06977611
ABSTRACT:
A receiver for detecting the presence of FM-CW signals emanating from a radio altimeter, and for determining the identity of the source. The received signals are amplified and applied both directly and through a delay circuit to a mixer. The delay is such that the resulting difference signal from the mixer is a low frequency signal in the audio frequency range. This signal is filtered, converted to digital values, and processed by fast Fourier transform techniques. Once processed, the spectral content of the difference signal is analyzed to determine if the signal originated from an airborne altimeter. Characteristics of the original signal modulation are also analyzed to ascertain the identity of the altimeter and its transporting aircraft.
REFERENCES:
patent: 3500401 (1970-03-01), Miller et al.
patent: 3713153 (1973-01-01), Van Popta
patent: 3758856 (1973-09-01), Fromm
patent: 3868685 (1975-02-01), Wilmot
patent: 3870996 (1975-03-01), Miller
patent: 3894219 (1975-07-01), Weigel
patent: 3896442 (1975-07-01), Heminway et al.
patent: 3987285 (1976-10-01), Perry
patent: 4016565 (1977-04-01), Walker
patent: 4017859 (1977-04-01), Medwin
patent: 4173760 (1979-11-01), Garrison
patent: 4236159 (1980-11-01), Alpers
patent: 4270180 (1981-05-01), Charlton
patent: 4297702 (1981-10-01), Carnes
patent: 4355368 (1982-10-01), Zeidler et al.
patent: 4398196 (1983-08-01), Wiegand
Hellner Mark
Northrop Grumman Corporation
LandOfFree
FM-CW altimeter detector does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with FM-CW altimeter detector, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and FM-CW altimeter detector will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3502950