July 2019
Spotlight Summary by Dennis K. Killinger
Extinction imagers for measurements of atmospheric beam transmittance
The authors have for the first time to their knowledge developed a new Extinction Imager (EI) system that can measure from a single end the extinction and transmission of the atmosphere in all 360 degree directions related to the surrounding scenes for a ground- or ocean-based imaging camera type system, without the need for double-ended, laser based transmission/scatter measurements or point scatter meters (PSMs). The system operates in the visible and short wave IR (near 1.6 µm), and uses the measured contrast between ocean surfaces and waves/clouds/distant hills to improve on the imaging of distant scenes. What is unique about their system is that they have developed new single-ended radiance equations for non-100% contrast calibration targets, which has allowed them to develop new, improved images using less than ideal and more realistic targets without requiring a black contrast calibration target. The new system has been extensively tested in the field overlooking a 180-degree view of the ocean and has shown improvement in the processed digital camera images. In addition, their new algorithms include logic to help find the apparent location of a target in the image even if the apparent location has changed due to atmospheric refraction or turbulence.
You must log in to add comments.
Add Comment
You must log in to add comments.
Article Information
Extinction imagers for measurements of atmospheric beam transmittance
Janet E. Shields and Monette E. Karr
Appl. Opt. 58(20) 5486-5495 (2019) View: Abstract | HTML | PDF