引言红外前视传感器噪声等效温差(NE-TD)的一般表达形式为:传感器的信噪比与成象光学装置的F数平方成反比。但对于接近背景限的系统来说,这个结论是不正确的。因为,加适当冷屏的探测器阵列的探测率随F数的变化是要把随F数的变化基本加以消除。所以,按下式考虑更为合适 Introduction The general expression of noise equivalent temperature difference (NE-TD) for infrared foresight sensor is that the signal-noise ratio of the sensor is inversely proportional to the square of F number of imaging optics. But for the system close to the background limit, this conclusion is not correct. Because, with a suitable cold-screen detector array detection rate with the F number of changes is to change with the F-number to be basically eliminated. Therefore, the following formula to consider more appropriate