David J Moretti, 6971 Woodmark Way, Wakefield, RI 02879

6594198, Jul 15, 2003

Oct 10, 2001

09/977904

Michael Amaral - Westport MA
Gregory H. Ames - Wakefield RI
Christopher M. Hansen - Hope Valley RI
David J. Moretti - Wakefield RI

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

H04B 1700

367 13, 367149

A system for digitally demodulating optical hydrophone signals is provided. The system includes an optical hydrophone connected to an analog-to-digital converter and further connected to a digital signal processor. Within the digital signal processor, a demodulator is calibrated by a preferred automatic calibration circuit such that mixer frequencies are coherently mixed with the incoming acoustic signals received by the hydrophone. The automatic calibration circuit preferably determines an extreme case of phase offset by following a programmable routine including a series of tests. After the extreme case is detected, the precise phase calibration is known and provided to the demodulator mixer tables. The automatic calibration circuit can be utilized for automatic calibrations of multisensor systems containing large numbers of hydrophones.

7382780, Jun 3, 2008

Apr 4, 2005

11/101115

David J. Moretti - Wakefield RI, US
John A. Fitzgerald - Bristol RI, US
Daniel Dufresne - Somerset MA, US
Ramon A. Garcia - Saunderstown RI, US

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

H04L 12/28
H04L 12/56

3703951, 370473, 370474, 370503

A method of transmitting data includes synchronizing a system clock with a real time clock. Digital data is collected from multiple sources at a system clock time. A sample counter provides a count for each system clock time. The digital data for each source is associated with the count. A data cell is composed from the digital data associated with at least one count and a source identifier. A data frame is created from the data cells from every source. A cell frame is created from a plurality of data frames, and a time frame is composed from a plurality of cell frames. A heads-up cell including the count is transmitted before the time frame. A time/count cell including the count and the real time is transmitted with the associated time frame.

6147930, Nov 14, 2000

Feb 2, 1999

9/360718

David J. Moretti - Wakefield RI
Michael Amaral - Westport MA
Antonio L. Deus - Saunderstown RI
Gerald L. Assard - Waterford CT

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

G01B 902

367149

A system for digitally demodulating optical hydrophone signals is provided. The system includes an optical hydrophone connected to an analog-to-digl converter and further connected to a digital signal processor. Within the digital signal processor, a basic demodulator has a first and second mixing tables, the first table operating at a modulating frequency,. omega. , injected into reference legs of the hydrophone, and a second table operating at 2. omega. The mixer frequencies are coherently mixed with the incoming acoustic signals received by the hydrophone. An automatic calibration circuit which adjusts the phase of the mixers is connected to the basic demodulator.

6098178, Aug 1, 2000

May 22, 1998

9/090224

David J. Moretti - Wakefield RI
John A. Fitzgerald - Bristol RI

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

G06F 104

713500

A time synchronized multi-processor system and a method for determining the absolute time when an event occurs in the system are described. The sys has a plurality of processor elements, a system clock for generating a periodic time signal which is received by each of the processor elements, event reports generated by at least one of the processor elements, a system controller for reading the event reports, and a time board for generating an interrupt signal which causes the system controller to read the event report and to determine the absolute time of the event. The method for determining the absolute time when the event occurs in the system comprises the steps of providing a plurality of processor elements, providing a system clock for generating a time signal, detecting an event and providing at least one processor element with a signal representative of the event, generating an event report with the processor(s) and periodically generating a second or interrupt signal using a time board for causing a system controller board to search for any such event report, read the event report, and determine the absolute time of day of any event in the event report.