Hello ALL: I should clarify that while the company is young, the technology really does date back a ways to patent number 4381544 submitted on Nov. 7, 1980.
Apologies to those who have seen this before.
patents.uspto.gov 96+OF+1+1+1+PN%2f4381544
Here's some additional patent research for those who enjoy such:
United States Patent 4,575,684StammMar. 11, 1986
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Differential phase shift keying receiver
Inventors: Stamm; Thomas A. (Chicago, IL). Assignee: Honeywell Inc.
(Minneapolis, MN). Appl. No.: 704,433Filed: Feb. 22, 1985Intl. Cl. : H03D
3/18Current U.S. Cl.: 329/307; 329/310; 375/330Field of Search: 329/50,122, 124; 375/81, 83, 84, 94, 120
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A receiver for demodulating differential phase shift keying data, the datahaving bit values dependent upon whether the phase of a carrier is invertedor not inverted during a bit interval, the receiver having a phase locked loop oscillator for locking up with the phase of the carrier, a phase detector for sensing differences in phases between the oscillator signaland the incoming data, an oscillator controller for controlling the output phase of the oscillator in response to the phase detector, a phase sense detector which detects whether or not the carrier has been inverted, a data clock responsive to the oscillator and to the phase sense detector for providing a data clock signal defining a bit interval, and a bit detector responsive to the phase sense detector, the data clock and the oscillator for integrating the incoming data.
I am speculating that they are using the Vadnais radar:
United States Patent 5,325,095Vadnais, et. al.Jun. 28, 1994
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Stepped frequency ground penetrating radar
Inventors: Vadnais; Kenneth G. (Ojai, CA); Bashforth; Michael B. (Buellton,CA); Lewallen; Tricia S. (Ventura, CA); Nammath; Sharyn R. (Santa Barbara,CA). Assignee: The United States of America as represented by the United States Department of Energy (Washington, DC). Appl. No.: 913,494Filed: Jul.
14, 1992Intl. Cl. : G01S 13/24, G01S 13/04Current U.S. Cl.: 342/22;
342/129; 342/194Field of Search: 342/22, 129, 194, 196
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References Cited | [Referenced By]
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U.S. Patent Documents
4,218,678Aug., 1980Fowler et al.343/5.FT4,381,544Apr.,
1983Stamm364/4204,435,708Mar., 1984Kyriakos343/12.A4,504,833Mar.,
1985Fowler et al.343/5.NA4,507,602Mar., 1985Aguirre342/22 X4,620,192Oct.,
1986Collins342/1284,670,753Jun., 1987Vacanti342/904,677,438Jun.,
1987Michiguchi et al.342/22 X5,192,952Mar., 1993Johler342/225,280,284Jan.,
1994Johler342/22
Abstract
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A stepped frequency ground penetrating radar system is described comprising an RF signal generating section capable of producing stepped frequency signals in spaced and equal increments of time and frequency over a preselected bandwidth which serves as a common RF signal source for both a transmit portion and a receive portion of the system. In the transmit portion of the system the signal is processed into in-phase and quadrature signals which are then amplified and then transmitted toward a target. The reflected signals from the target are then received by a receive antenna and mixed with a reference signal from the common RF signal source in a
mixer whose output is then fed through a low pass filter. The DC output,after amplification and demodulation, is digitized and converted into a frequency domain signal by a Fast Fourier Transform. A plot of the frequency domain signals from all of the stepped frequencies broadcast toward and received from the target yields information concerning the range(distance) and cross section (size) of the target. |
