A Theoretical Analysis of Changes in Thermal Signatures Caused by Physical and Climatological Factors.

摘要

An investigation of the thermal signatures of natural objects is undertaken. Using the principle of energy balance, diurnal temperature models are developed for the ground, a vehicle (such as a tank), and the leaves of a tree. These models are included in a computer program designed to simulate daily variations in conductive, radiative, and convective heat transfer processes. Environmental conditions are changed by altering the program inputs, which include; latitude, day, wind speed, mean air temperature, cloud type, total insolation, absolute and relative humidity, atmospheric pressure, and particular concentration. The program is iterated for several values of a single parameter such as one of the environmental inputs, or one of 21 physical characteristics of the models (for example; ground reflectivity, tank thickness, or leaf transpiration rate). There are two types of output from the program; simultaneous plots of the temperatures of all the models for a 30-hour period, and curves representing 24-hour periods of the temperature difference (Delta-T) between the tank and the ground. The effects of changing a parameter are analyzed by comparing the various Delta-T curves.