Sensitivity Analysis of Reflection Errors in Infrared Image Simulation

摘要

The question of how much error is present in a simulated infrared signature if reflections are neglected was studied using a sensitivity analysis approach. The purpose of this study was to determine whether it is necessary to model reflections in the current FSTC method of simulating IR signatures. To gain insight the following steps were performed: 1) A sensitivity analysis approach was chosen for the study, 2) An equation isolating the major components of an IR signature was derived, 3) The equation was used to determine error present in a simulation when emissivity was estimated to be always 0.95. This was accomplished by using a simulation of a complicated tank applied with actual, measured emissivity that had specular characteristics, 4) A weighted average error figure was derived and applied to the results of histogramming emissivities for the simulated tank, and 5) It was determined that in some cases, error could be as high as 35% on an absolute scale. However, most of the errors calculated in section 3.0 were found to be less than 10%, which corresponds to about 6 K apparent temperature error for ambient targets. (RH)