Inclusion of a Simple Vegetation Layer in Terrain Temperature Models for Thermal Infrared (IR) Signature Prediction
Abstract
Thermal infrared signatures of natural and cultural features are dynamic, varying with time and weather conditions. Prediction of thermal signatures for specific conditions requires first that the actual temperature of the features be determined; for vegetation canopies this involves the average temperatures of canopy components and for planar (nonvegetated) surfaces the temperature of the surface. Models have been developed to handle layered vegetation canopies and layered ground surfaces; however, efforts have only begun to formulate a comparable capability for intermediate conditions such as grass covered surfaces where both the terrain surface and vegetation influence the average surface temperature. This report presents a procedure, named VEGIE, that predicts the temperature of terrain surfaces which contain a simple layer of vegetation. VEGIE is designed as an interim procedure for immediate application in lieu of more sophisticated and theoretical treatments of this problem. Operational flexibility and simplicity are preserved by using VEGIE as a submodel to the Terrain Surface Temperature Model (TSTM) developed previously at the U.S. Army Engineer Waterways Experiment Station. The TSTM predicts the surface temperature of nonvegetated layer and planar features using material thermophysical properties and meteorological conditions. These models are applied to a deciduous and a coniferous canopy where the CSU model is valid but VEGIE is not. VEGIE is applied to the problem of estimating thermal signatures for terrain surfaces with less than total foliage cover, the consequences of changes in foliage cover, differing emissivities for the soil and vegetation, and reflected sky radiation.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1981
- Accession Number
- ADA104469
Entities
People
- Lee K. Balick
- Lewis E. Link Jr.
- Randy K. Scoggins