Abstract: An amplifier for use in a buoyant cable antenna operable to receive signals within a frequency band includes: a first amplifier operable to provide amplified signals based on the received signals; a bandpass filter arranged to pass filtered signals within a first portion of the frequency band, the filtered signals being based on the amplified signals; an attenuator arranged in parallel with said bandpass filter and operable to attenuate signals within a second portion of the frequency band, the attenuated signals being based on the amplified signals; and a second amplifier operable to provide an amplified output including first amplified signals within the first portion of the frequency band and to provide second amplified signals within the second portion of the frequency band. The first amplified signals have a first gain, the second amplified signals have a second gain, and the first gain is more than the second gain.

Abstract: An amplifier for use in a buoyant cable antenna operable to receive signals within a frequency band includes: a first amplifier operable to provide amplified signals based on the received signals; a bandpass filter arranged to pass filtered signals within a first portion of the frequency band, the filtered signals being based on the amplified signals; an attenuator arranged in parallel with said bandpass filter and operable to attenuate signals within a second portion of the frequency band, the attenuated signals being based on the amplified signals; and a second amplifier operable to provide an amplified output including first amplified signals within the first portion of the frequency band and to provide second amplified signals within the second portion of the frequency band. The first amplified signals have a first gain, the second amplified signals have a second gain, and the first gain is more than the second gain.

Abstract: An aspect of the present invention is drawn to method of determining a location of a submersible vehicle. The method 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.

Abstract: An aspect of the present invention is drawn to method of determining a location of a submersible vehicle. The method 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.