Buoyant Cable Antenna Amplifier With Selective AIS Signal Gain
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Solution Overview
Problem
Conventional methods for submersible vehicles to determine their location underwater are prone to inaccuracies due to error accumulation in inertial guidance systems and are limited by the inability to receive GPS signals below periscope depth, leading to safety issues and unreliable navigation.
Innovation Solution
A system and method utilizing Automatic Identification System (AIS) data from nearby vessels, combined with sonar information, to calculate the submersible vehicle's location independently of sensor position, and an improved inline amplifier design that selectively amplifies AIS signals while maintaining amplification of other frequency bands, allowing for accurate positioning even when submerged.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional inertial guidance systems are used for location determination, then the submersible vehicle can operate submerged, but accumulated error leads to significant location inaccuracies
Solution Approach 1:
The patent introduces an intermediary system consisting of a buoyant cable antenna extending to the surface and an inline amplifier to mediate between GPS satellites and the submerged vehicle. The antenna transmits GPS signals through water to the vehicle, while the amplifier boosts these weak signals, enabling accurate location determination without inertial drift accumulation.
2Measurement precision
If GPS signals are received at periscope depth with antenna extended above surface, then accurate location determination is achieved, but the submersible vehicle cannot operate fully submerged
Solution Approach 1:
The patent transitions the antenna from a surface-based configuration to a buoyant cable antenna that operates in the vertical dimension, extending from the submerged vehicle through the water column to the surface. This dimensional change allows the vehicle to remain fully submerged while the antenna reaches GPS signals from above, resolving the contradiction between submerged operation and GPS reception.
Solution Approach 2:
The buoyant cable antenna acts as an intermediary that bridges the gap between the submerged vehicle and GPS satellites. By extending the antenna through water to the surface, it mediates signal transmission across the water-air interface, enabling full submerged operation with continuous GPS access.
3Power
If inline amplifier is used to amplify GPS signals through the buoyant cable, then signal strength is increased, but signal attenuation in the frequency band still reduces reception quality
Solution Approach 1:
The patent applies local quality by making the amplifier selective to specific frequency bands. Instead of uniformly amplifying all frequencies, the amplifier is designed to selectively amplify GPS signal frequencies while attenuating other frequencies. This targeted approach increases signal power where needed while minimizing the impact of attenuation from noise and interference in other bands.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables accurate and reliable location determination of submersible vehicles underwater by using AIS data and sonar information, providing GPS-level fixes without relying on surface-based sensors and overcoming signal attenuation issues.
Implementation Method 1
The amplifier provides a first gain for signals within a first frequency band and provides a second gain for signals within a second frequency band, wherein the first gain is greater than the second gain
Implementation Method 2
The amplifier can be arranged to provide signal attenuation in frequency bands outside of a desired frequency band
Implementation Method 3
The amplifier includes a bandpass filter arranged to pass filtered signals within a first portion of the frequency band, wherein the filtered signals are based on the amplified signals
Data Source
AI summary
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.