William M Waters

US Patent:

H002015, Mar 5, 2002

Filed:

Mar 31, 1995

Appl. No.:

08/414824

Inventors:

William M. Waters - Millersville MD

Assignee:

The United States of America as represented by the Secretary of the Navy - Washington DC

International Classification:

H04B 166

US Classification:

375240

Abstract:

This invention is a communication system utilizing sharply bandlimited waveforms for sampled data communications computed for each sample value in a sequence of data samples. The computed waveform is centered at a sample point, weighted by a corresponding data value, and truncated outside an appropriate time interval. Sampled digital data in a sequence of data samples is received by a computer and scaled according to the value r(t ). A waveform generator, controlled by a computer, generates a sharply bandlimited keying waveform for each data sample and weights each waveform with the data and forms the sum of weighted waveforms to form the output signal in digital form which is converted to analog form. The analog output of the waveform generator is passed through a low-pass filter to filter out any harmonics generated, up-converted to produce a desired carrier frequency which can then be multiplexed, if required, and output as radio frequency (RF) energy which can be received by any standard receiver.

US Patent:

45742871, Mar 4, 1986

Filed:

Mar 4, 1983

Appl. No.:

6/472330

Inventors:

William M. Waters - Millersville MD

Assignee:

The United States of America as represented by the Secretary of the Navy - Washington DC

International Classification:

H01Q 19195

US Classification:

343756

Abstract:

A beam scanning antenna system that uses a small, rapidly rotatable feed enna to illuminate a large, fixed secondary collimating device, such as a reflector or electromagnetic lens, which in turn illuminates a large, fixed primary collimating device. The primary collimating device forms a narrow collimating beam that is reflected or transmitted into space. Rotation of the small feed antenna causes the beam to scan.

US Patent:

43689876, Jan 18, 1983

Filed:

Jun 25, 1980

Appl. No.:

6/163001

Inventors:

William M. Waters - Millersville MD

Assignee:

The United States of America as represented by the Secretary of the Navy - Washington DC

International Classification:

G04C 1100
H04J 306

US Classification:

368 46

Abstract:

A method for synchronizing a master clock and a remote slave clock which nominally has the same pulse frequency but may be out of time-phase comprising transmitting a master pulse to the slave, measuring the time delay,. DELTA. tau. , between the received pulse and the nearest succeeding (in time) slave pulse, delaying the latter slave pulse by. DELTA. tau. to provide a conjugate slave pulse, transmitting the conjugate pulse to the master station and measuring the time difference. DELTA. between time of reception of the conjugate pulse and time of generation of the original master pulse. The time. DELTA. is equal to twice the error between the master and slave pulses. The process can also be done at the slave station if the slave pulse is transmitted to the master and a conjugate-phase master pulse is retransmitted to the slave where the measurement is accomplished. The phase of the slave pulse can then be adjusted by. DELTA. /2 to synchronize it with the master pulse.

US Patent:

43640486, Dec 14, 1982

Filed:

Aug 13, 1980

Appl. No.:

6/177707

Inventors:

William M. Waters - Millersville MD
George J. Linde - Accokeek MD

Assignee:

The United States of America as represented by the Secretary of the Navy - Washington DC

International Classification:

G01S 722

US Classification:

343 5EM

Abstract:

A system, which interfaces with a radar indicator, for improving signal-toise ratio (SNR) and enhancing the detection of moving targets includes an analog-to-digital (A/D) converter, an integrator, a digital memory, a digital-to-analog (D/A) converter, and a synchro-to-digital converter. Radar video is converted to digital signals which are integrated and stored in memory. The angle signal from the antenna pedestal synchro is fed to the synchro-to-digital converter and stored in memory. The contents of the memory is processed, converted to analog form, and fed to the indicator. The radar provides a number M of sweeps within each beamwidth, or angular sector, of the antenna during each antenna scan. Contiguous sets of M sweeps are added to form batches. The signal content for each batch is displayed on the indicator in the angular sector which is identified with the M sweeps.

US Patent:

H1448, Apr 7, 1992

Filed:

Dec 28, 1990

Appl. No.:

7/635022

Inventors:

William M. Waters - Millersville MD

Assignee:

United States of America - Washington DC

International Classification:

G04C 1102
G01S 1308

US Classification:

368 47

Abstract:

Methods for accurately measuring the range between two platforms with relative motion between them using a stable clock located on each platform. A series of pulses are sent from one platform to the other at times known to each platform by prearrangement, the arrival times measured, and statistical methods used to calculate a correction from the clocks to bring them into greater synchronization, thus allowing highly accurate determination of the range between the two platforms.

US Patent:

51072700, Apr 21, 1992

Filed:

Jun 22, 1990

Appl. No.:

7/541991

Inventors:

William M. Waters - Millersville MD

Assignee:

The United States of America as represented by the Secretary of the Navy - Washington DC

International Classification:

G01S 1346
G01S 13524

US Classification:

342111

Abstract:

Method and apparatus for improving detection ranges of a pulsed radar sys wherein electromagnetic return signal data in range cell order is doppler filtered, digitized and stored in doppler memory channels over multiple scans of an azimuth. The digital doppler data in each doppler memory channel is scan-to-scan integrated over a predetermined number of scans to produce target displays for each possible velocity. The target displays are stored in a velocity memory, which is partitioned into velocity channels, each velocity channel corresponding to one possible velocity. A selector selects the target display having the largest total magnitude as a display signal. The scan-to-scan integrated target displays are not subject to collapsing losses since only target signals plus noise signals will be stored in the doppler memory channel corresponding to the target's velocity.

US Patent:

51557410, Oct 13, 1992

Filed:

Jan 31, 1991

Appl. No.:

7/648696

Inventors:

William M. Waters - Millersville MD
George J. Linde - Accokeek MD

Assignee:

The United States of America as represented by the Secretary of the Navy - Washington DC

International Classification:

H04K 100

US Classification:

375 1

Abstract:

A communications system which decreases noise errors and increases informon rate without sacrificing bandwidth is formed by a transmitter and a receiver designed to handle long pulse compression wavforms. An encoder connected to the transmitter converts a voice message into digitized voice words, encodes the digitized voice words into the time shifted code sequences, and phase modulates the long pulse compression waveform, producing a M-ary coded signal at the output of the transmitter. The receiver is connected to a decoder which includes at least one convolver for computing the correlation of received digitally coded words with independently generated time shifted code sequences, and a controller for generating a plurality of data values according to the largest correlation values, and a transducer responsive to the data values.

US Patent:

54225841, Jun 6, 1995

Filed:

Sep 30, 1992

Appl. No.:

7/953380

Inventors:

William M. Waters - Millersville MD

Assignee:

The United States of America as represented by the Secretary of the Navy - Washington DC

International Classification:

H03B 1900
H03L 700

US Classification:

327113

Abstract:

A waveform generator is provided for generating a high frequency waveform. A pulse generator provides a pulse train at a low frequency. A pulse converter converts the pulse train into an alternatingly positive and negative groups of pulses. A bandpass filter passes the alternatingly positive and negative groups of pulses in a frequency band centered at the high frequency to output the generated waveform at the high frequency. When the groups of pulses are a pair of pulses, a sine wave is output from the bandpass filter. A pulse delay circuit can be used to variably delay the pulse train and thereby cause a phase change in the generated waveform.