噪声等效温差对于红外系统的性能评价，对于检验红外系统性能来提高红外系统设计水平、降低成本、缩短研制 和生产周期都有非常重要的作用。噪声等效温差是衡量红外探测器系统性能的重要指标之一。它与总体大气透过率、探测器性能参数等因 素有关。本文推导了噪声等效温差的表达式，以特定的红外探测器为例，通过噪声等效温差表征了探测器的性能，并且通过编写程序检验了 各个因素对探测器性能的影响。

Noise equivalent temperature difference is of great importance to the evaluation of the performance of infrared systems. It is helpful to the performance improvement, cost reduction and production periode shortening of infrared systems. Noise equivalent temperature difference is one of the important specifications for measuring the performance of infrared detector systems. It is related to the total atmospheric transmittance and detector performance parameters etc.. The expression of the noise equivalent temperature difference is deduced. The performance of a particular infrared detector is characterized by using the noise equivalent temperature difference and various performance influence factors are examined through a special program we wrote.