Patent
Waveform encoded altitude sensor
TLDR
In this article, a spread spectrum waveform encoded altimeter is presented, where a plurality of individual detectors are used to detect an early chip or signal and another pair of detectors are provided to detect a late signal or signal.Abstract:Â
The present invention provides a spread spectrum waveform encoded altimeter. Spread spectrum carrier wave signals which are transmitted and later received are processed in a novel edge detecting apparatus which includes a plurality of individual detectors. A pair of detectors are provided to detect an early chip or signal. Another pair of detectors are provided to detect a late chip or signal. There is also provided a pair of edge chip detectors for detecting the center or locked on chip signal. Logic circuits are employed to sum the voltage signals from the detectors and to provide a control signal capable of adjusting a tracking generator to enable it to lock on to the received signal. An altimeter counter is provided which is started by a unique chip in the transmitted signal and stopped when the same unique chip is detected in the receiving and tracking loop.read more
Citations
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References
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Patent
Range and angle determining Doppler radar
TL;DR: In this article, a volume of interest is generated by a linear array with respect to the bisector of the volume and a receiving antenna is commutated element-by-element to provide a phase modulated received signal from which angle information may be derived.
Patent
Pseudo-randomly phase modulated radar altimeter
TL;DR: In this article, a pseudo-randomly phase modulated radar altimeter is presented, where the phase of a CW wave is shifted between 0* and 180* in a pseudo random fashion by a modulation code generator prior to transmission, and a reflected wave is demodulated in the same way by a tracking code generator.
Patent
Arrangement for measuring the lag between two timed signals by electronic correlation
Leon M Robin,Hawkes Thaddeus M +1 more
TL;DR: In this paper, the received coded signal is applied to two correlators followed by a subtractor to form a discriminator circuit utilized to lock the frequency of a generator which provides two reference coded signal utilized respectively for correlation and to form an automatic tracking loop.
Journal ArticleDOI
Double Dither Loop for Pseudonoise Code Tracking
TL;DR: It is shown that the double dither loop (DDL) combines the best features of the DLL and the TDL in that the DDL is insensitive to gain and offset imbalances and does not suffer the 3-dB degradation in noise performance typically associated with theTDL.