Minimum resolvable temperature difference
（重定向自MRTD）
Minimum resolvable temperature difference (MRTD) is a measure for assessing the performance of infrared cameras, and is inversely proportional to the modulation transfer function.
Typically, an operator is asked to assess the minimum temperature difference at which a 4 bar target can be resolved. This minimum difference will change with the spatial frequency of the bar target used. A curve of MRTD against spatial frequency is obtained which characterises the performance of the imaging system.