An Outline for the RTNEPH Infrared Atmospheric Water Vapor Attenuation Study
Abstract
The Real-Time Nephanalysis (RTNE PH) generates real-time global analysis of cloud extent, base, height, and type. The RTNE PH makes extensive use of satellite data that are measured in the 10-12 micron infrared (IR) window for thermal mapping of clouds and the earth's surface both day and night. Water vapor absorption effects are significant in such data, especially for high viewing angles and tropical atmospheres where water vapor concentrations are generally high. Water vapor attenuates the emitted ground radiance, reducing its magnitude and with it the apparent temperature of the surface being viewed. Currently, the RTNEPH takes into account such attenuation losses using lookup tables that are functions of viewing geometry, time of day, type of background, and the like. However, these corrections have limited value and leave room for significant improvement. This report outlines and presents two new techniques that are expected to enhance the attenuation correction capabilities of the RTNEPH, multivariate polynomial regression (the Weinreb technique) and the correlated K method. (JHD)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 29, 1989
- Accession Number
- ADA221753
Entities
People
- John-luc Moncet
- Larry W. Thomason
- Michael K. Griffin
- Robert P. D'entremont
- Todd R. Miller
Organizations
- Air Force Systems Command