There is disruption of free-space optical communications and imaging systems due to atmospheric optical turbulence

Optical communication relies on transmission of light through the atmosphere or vaccuum. Free-space point-to-point optical links typically use infrared laser light for signal transmission. Fluctuations in the refractive index along the path of light propagation can impede communications. There are many benefits to free-space optical communication (FSO), including its cost-effective ability to transmit a significant amount of data at great speed while requiring minimal power. FSO is finding utility in general communications, military, and space exploration applications. Despite high accuracy in the laser positioning, FSO is not immune to atmospheric optical turbulence (AOT) that can disrupt the signal and can cause a complete link failure. AOT can negatively impact other imaging systems, such as ground-based telescopes, because it effects the angular resolution. Methods to predict or forecast AOT could improve site selection of FSO communication nodes.

Suite of LIDAR tools provides quantitative AOT measurements that impact ground-based imaging systems, weather prediction, and modeling 

When using multiple LIDAR and Doppler LIDAR remote sensing instruments in concert, researchers have identified a new technique to measure profiles of atmospheric variables to accurately define optical turbulence (e.g., AOT strength measured in time and range). This novel measurement and algorithm technique uses statistical relationships between atmospheric variables measured at turbulence scales to quantify the strength of optical turbulence. This method is beneficial because the data products are range-resolved, the system is single-ended, and data can be acquired at arbitrary angles. Quantitative AOT measurements allow for better weather prediction and modeling, improved predictability of FSO or ground-based imaging systems’ performance, and additional insight into meteorological conditions. 

Solution Advantages
  • Simpler: The data products of this method are range-resolved, single-ended, and can be measured at arbitrary angles.
  • Enhanced: Quantitative measurements of optical turbulence with unprecedented spatial and temporal coverage offer improved performance for long-range FSO applications.
  • Traceable: Enhanced optical turbulence strength measurements as a function of time and range enables path for development of first of their kind traceability standards.
Potential Commercial Applications
  • Atmospheric monitoring and modeling
  • Meteorology
  • Test instrumentation
    • FSO
    • Optical imaging
       
Three graphs displaying the LIDAR measurements of temperature, wind, and water vapor that combine to display a fourth graph showing the measurement of turbulence.

Diagram of how each of the LIDAR instruments combine to provide a singular measurement for atmospheric optical turbulence.