Infrared

The light that our eyes can see represents a small part of the electromagnetic spectrum and consists of the colors seen in a rainbow, from reds and oranges, through blues and purples. Infrared is a region of the electromagnetic spectrum that is below the visible part of the electromagnetic spectrum, the red color, which explains the “infrared” name. Objects and heat sources emit infrared radiation that is related to the emissivity of a surface which characterizes its thermal emission. Infrared cameras allow measuring a portion of this radiation emitted within the spectral band it perceives and further analysis allows to determine the surface temperature.

Infrared imaging is commonly used in defence and security domains for many purposes such as target acquisition and surveillance, but also in other domains such as manufacturing for monitoring, quality control, etc.

As a part of the defence domain, LTI has developed a software tool that allows analysis of infrared images taken by different infrared cameras. This tool, named WinISAS (Windows based Infrared Signature Analysis Software), was intended to ease the analysis of infrared images conducted by scientists and even defence and military analysts. WinISAS supports different image formats up to 24-bit precision and allows digitizing images taken by analog infrared camera using a Matrox frame grabber. WinISAS is based on project files that are used to gather camera settings, environmental conditions, calibration information, images and regions of interest. Once the mandatory information is available, a radiometric and spatial calibration is performed, if required, and selected analyses are executed. The analysis results can be generated in a formatted report; this report includes project information, infrared images, calibration and analysis results. WinISAS supports an infrared analysis specified by a NATO research workgroup. The accuracy of WinISAS was clearly demonstrated during the SIMVEX 2001 field trials in Nova Scotia, Canada, where infrared signature analysis results were the best among NATO participants for the 5-8 microns infrared waveband. Although the WinISAS development has been completed in 2003, its quality and stability has been proven since it is still used nowadays by the Canadian Forces.

LTI’s experience related to infrared comprises:

• Experimentation
  • Camera calibration
  • Image acquisition
  • Environmental conditions
  • Field trials
• Analysis and simulation
  • Calibrated analysis
  • Signature analysis
  • Image processing
  • Signature prediction (infrared scene generation)
  • Atmospheric transmittance (MODTRAN)