Laser Communications System Using Atmospheric Scattering
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Solution Overview
Problem
Existing GPS and communications systems face signal blackouts and high loss areas in urban and rugged terrains, limiting their ability to provide high-speed data and position location services, especially for mobile units like emergency response vehicles.
Innovation Solution
A laser communications and position location system utilizing laser light beam concentration and atmospheric scattering, where a laser transmitter radiates beams upward to converge at a free space junction, scattering them for reception by a laser receiver, which modulates data and determines precise location, enabling high-speed data transmission and position location even in challenging environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If GPS systems are used for navigation in urban environments, then position location is provided, but signal blockage occurs in dense urban areas and rugged terrain
Solution Approach 1:
The patent uses atmospheric scattering (air molecules, water droplets, dust particles) as an intermediary to redirect laser beams from the transmitter to the receiver. This scattering mechanism allows the laser communication system to overcome line-of-sight blockages in urban canyons and rugged terrain, providing reliable communication where GPS fails.
Solution Approach 2:
The patent transitions from ground-based navigation (2D surface) to three-dimensional atmospheric space by transmitting laser beams upward through the atmosphere. The beams converge at a free space junction in the atmospheric dimension, allowing communication to bypass ground-based obstructions like buildings and terrain features.
2Productivity
If laser communications systems are used for high-speed data transmission, then data rate is improved, but line-of-sight requirement limits usability in rough terrain and urban canyon situations
Solution Approach 1:
The patent introduces atmospheric scattering as a mediator that enables laser beams to reach the receiver without direct line-of-sight. The scattering off air molecules, water droplets, and dust particles creates a diffuse propagation path that works in rough terrain and urban canyons while maintaining high data transmission rates.
Solution Approach 2:
The patent makes the laser communication system universal by enabling it to operate in multiple environments including clear skies, urban canyons, and rugged terrain. The system can function in both direct line-of-sight conditions and scattered light conditions, providing versatile communication capability across diverse geographical locations.
3Productivity
If conventional laser communications are used, then high-speed data transmission is achieved, but system complexity and cost increase
Solution Approach 1:
The patent employs inexpensive laser diodes operating at standard wavelengths (650nm red, 480nm blue, 445nm violet) instead of expensive specialized laser systems. These off-the-shelf laser diodes can be easily replaced and are significantly cheaper than conventional laser communication components, reducing overall system complexity and cost.
Solution Approach 2:
The patent optimizes communication performance by changing parameters such as laser wavelength, pulse duration (ultra-short pulses), and modulation techniques. By using ultra-short pulses and optimizing the wavelength for atmospheric transmission, the system achieves high data rates with simple, low-cost laser diodes rather than complex, expensive laser systems.
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
This system provides reliable, high-data-rate, low-cost communications and position location services in urban canyons and rugged terrains, overcoming signal blockages and offering covert, precise vehicle positioning with low-power, ultra-short laser pulses.
Implementation Method 1
A laser communications and position location system using laser light beam concentration and atmospheric scattering is disclosed. The laser beams are scattered at the free space junction and a laser receiver receives scattered laser beam light.
Data Source
AI summary
A laser communications and position location system has a laser transmitter with a laser array radiating modulated laser beams upward at convergence angles that determine altitude of a free space junction where the beams converge. The free space junction scatters the modulated laser beams and a laser receiver receives the scattered modulated laser beam light and recovers the data. A modulator modulates the laser array with data. The laser transmitter may include a data link to transmit the free space junction position to the laser receiver to aid in finding it. The laser receiver has an optical detector with an adjustable field of view and gain to minimize background light noise and to demodulate the received modulated scattered laser beams. The laser receiver determines a precise location of the laser transmitter upon finding the free space junction.