Technologies


System and Method for Determining Location of Submerged Submersible Vehicle

Reference#: P02672


Conventional methods employed by submersible vehicles to determine their location when submerged are prone to inaccuracies or unreliable. More accurate methods used when on the surface are not available when submerged below periscope depth.

One conventional method submersible vehicles use for determining their location is with inertial guidance systems. Inertial guidance systems operate by monitoring acceleration and changes in rotational attributes like pitch, roll and yaw. This data along with the submersible vehicle's speed is processed by a computer to determine the current position of the submersible vehicle. Unfortunately, inertial guidance systems suffer from accumulated error. Any errors in measurement of the rotational attributes are accumulated. With enough error accumulation, the total error can become significant enough to cause safety issues as the operators of the submersible vehicle think they are at a particular location, but are actually at a very different location.

Submersible vehicles have several other methods for navigation including sonar, radar, radio and Global Positioning System (GPS). Each of these methods has limitations with respect to their use. Submersible vehicles may operate in stealth mode wherein active sonar and radar methods of navigation may not be used because such methods may enable outside observers to determine the location of the submersible vehicle. Submersible vehicles can determine their location with radio navigation and a GPS, however both of these methods require the submersible vehicle to operate at periscope depth and extend an antenna above the surface of the body of water.

APL researchers have developed a system and method for a submersible vehicle to accurately determine its location when submerged.

One method for determining a location of a submersible vehicle includes obtaining first bearing information based on a location of a ship at a first time relative to the submersible vehicle and receiving broadcast information from the ship, wherein the broadcast information includes location information related to a second location of the ship at a second time, a velocity of the ship at the second time and a course of the ship at the second time. The method further includes obtaining second bearing information based on the second location of the ship at the second time relative to the submersible vehicle, obtaining a velocity of the submersible vehicle at the second time and obtaining a course of the submersible vehicle at the second time. The method still further includes determining the location of the submersible vehicle based on the first bearing information, the second location of the ship at the second time, the velocity of the ship at the second time, the course of the ship at the second time, the second bearing information, the velocity of the submersible vehicle at the second time and the course of the submersible vehicle at the second time.

Another method of determining a location of a submersible vehicle includes receiving first broadcast information from a first ship, wherein the first broadcast information includes first location information related to a location of the first ship. The method additionally includes receiving second broadcast information from a second ship, wherein the second broadcast information includes second location information related to a location of the second ship. Further, the method includes obtaining first bearing information based on the location of the first ship relative to the submersible vehicle and obtaining second bearing information based on the location of the second ship relative to the submersible vehicle. Still further, the method includes determining the location of the submersible vehicle based on the first broadcast information, the second broadcast information, the first bearing information and the second bearing information.

APL researchers have developed an amplifier for use in a buoyant cable antenna operable to receive signals within a frequency band. The amplifier includes a first amplifier, a bandpass filter, an attenuator and a second amplifier. The first amplifier can provide amplified signals based on the received signals. The bandpass filter is arranged to pass filtered signals within a first portion of the frequency band, wherein the filtered signals are based on the amplified signals. The attenuator is arranged in parallel with the bandpass filter and is operable to attenuate signals within a second portion of the frequency band, wherein the attenuated signals are based on the amplified signals. The second amplifier can provide an amplified output including first amplified signals within the first portion of the frequency band and can second amplified signals within the second portion of the frequency band. The first amplified signals have a first gain, whereas the second amplified signals have a second gain. The first gain is more than the second gain.

Patent Status: U.S. patent(s) 8,736,380; 8,289,811 issued.

CONTACT:
Mr. J. E. Dietz
Phone: (443) 778-2782
ott-techmanager5@jhuapl.edu

Additional References:

Link to U.S. Patent and Trademark Office