What is the MRTD test?

The MRTD (Minimum Resolvable Temperature Difference) is a standard performance measurement for Thermal Imagers. This measurement leads to the determination of the DRI ranges (Detection, Recognition, Identification ranges) of the infrared camera under test.

The MRTD measurement is performed using:

  • a differential blackbody, as the infrared reference source
  • a four-bar target, as the reference object, positioned in front of the emissive surface of the reference source
  • a collimator projecting the object in front of the camera under test

The differential blackbody enables to set a positive or negative temperature difference between the target bars and their background (the emissive surface of the blackbody). The MRTD curve is plotted by determining the minimum temperature difference between the target and the background, required to distinguish the 4 bars on the thermal image of the camera, as a function of the spatial frequency of the 4-bar target.

To perform a fast and accurate MRTD test, patterns of 4-bar targets, with optimized spatial frequencies, can be computed depending on the Field of View and the resolution of the camera, and on the focal length of the collimator. Download our calculation sheet to determine the target pattern suiting your needs.

For more information, do not hesitate to contact our specialists.