A method for modeling of the IR signature of vehicles. Measurements and calculations

Authors:

  • Jan Fagerström
  • Nils Karlsson
  • Roland Lindell
  • Jonas Rahm

Publish date: 2012-12-28

Report number: FOI-R--3591--SE

Pages: 30

Written in: Swedish

Keywords:

  • Thermal calculation
  • temperature measurement
  • IR modeling
  • signature modeling
  • IR measurement
  • signature measurement
  • LWIR
  • SWIR
  • RadThermIR.

Abstract

In previous work in the project validation of thermal and radiometric calculations against measured data was carried out by studying simple, well defined generic objects. The present study presents a method to model thermal properties and infrared signature properties of realistic and more complex objects. The method is applied to a Volvo V70, but could be used for military vehicles as well. Reference data for validation was collected by measuring the radiance, as well as the temperature at a number of positions on the vehicle. The radiance was measured in the wave length bands 2.8-5 µm and 7.5-14 µm. Weather data was collected using a weather station. The position of the vehicle was fixed but its orientation was varied and its engine was left running one hour each day. Temperature and radiance were calculated. As input to the calculations a CAD-geometry in combination with thermal and optical material data were used. Many of the parameters in the model are only roughly estimated. With this kept in mind, the results show an overall good agreement between calculated and measured values in terms of both temperature and radiance. However, discrepancies exist, and are discussed in the report. Several suggestions of further work to improve modeling of thermal modeling and infrared signature modeling of complex objects are given, for example improved material characterization and geometrical description.