Abstract: This invention relates to a GPS navigation system comprised of a submerged vessel having a navigation processor associated via buoyant cable with a buoy having a GPS device; wherein the cable contains: a data link between the vessel and the GPS device; and a location device for the determination of the location of the cable to the vessel; and wherein the processor computes a GPS position relative to the vessel. The invention also relates to a navigation process comprising the steps of: attaching a cable between a buoy and a submerged vessel; providing a GPS data relative to the buoy and cable location data over the cable to the submerged vessel; and using the GPS position of the buoy and location data to compute the GPS position of the submerged vessel.

Abstract: This invention relates to a GPS navigation system comprised of a submerged vessel having a navigation processor associated via buoyant cable with a buoy having a GPS device; wherein the cable contains: a data link between the vessel and the GPS device; and a location device for the determination of the location of the cable to the vessel; and wherein the processor computes a GPS position relative to the vessel. The invention also relates to a navigation process comprising the steps of: attaching a cable between a buoy and a submerged vessel; providing a GPS data relative to the buoy and cable location data over the cable to the submerged vessel; and using the GPS position of the buoy and location data to compute the GPS position of the submerged vessel.

Abstract: A method of estimating velocity with a correlation SONAR that provides an improved velocity estimate due to a reduction in random and bias errors is disclosed. The method generates a velocity estimate based on a weighted average of pulse-pairs that includes processing of those pulse-pairs based on an optimal correlation time as well as pulse-pairs based on sub-optimal correlation times.

Abstract: A correlation SONAR that provides improved velocity estimates due to a reduction in random and bias errors is disclosed. Rather than basing the velocity estimate on a single set of primary receiver pairs, one or more additional velocity estimates are generated based on one or more available receiver pair sets having the same velocity vectors as the primary receiver pairs set. Additional velocity estimates also provide a reliability and accuracy improvement by enabling identification and subsequent elimination of erroneous velocity estimates.

Abstract: A sonar system comprises a transmitter adapted to provide pulse sequences, wherein each of the pulse sequences includes pulses that reflect off an object, a receiver adapted to receive the reflected pulses, and a processor. The processor is configured to transmit a first pulse sequence via the transmitter to obtain a first distance to the object in a first distance range and to transmit a second pulse sequence via the transmitter to obtain a second distance to the object in a second distance range. The processor is configured to transmit the second pulse sequence in response to being unable to obtain the first distance to the object in the first distance range.

Abstract: In accordance with the illustrative embodiment, a diagnostic method for use with multi-element transducers includes determining an acoustic center of a transducer and determining an offset of the determined acoustic center from a theoretical acoustic center of the transducer. In some embodiments, the method also quantifies the impact that the offset has on performance of a transducer array. In some embodiments, the offset is used to correct signal processing calculations that rely on assumptions about the acoustic center of each transducer in the transducer array. A diagnostic system for use with multi-element transducers includes a projector, wherein the projector generates a sound; and a mechanical fixture, wherein the fixture aligns the projector with the transducing elements in the transducer so that in combination, the projector selectively ensonifies each of the transducing elements in the transducer.