为解决热像仪测试设备校准问题，设计了内部参考黑体温度与环境温度相等的红外辐射计。为评估精密红外辐射计的性能指标，指导精密红外辐射计的设计，建立了红外辐射计NETD (噪声等效温差，Noise equivalent temperature difference)数学模型。估算了在不同电子带宽、光谱波段下红外辐射计的NETD。结果表明，当噪声带宽小于1 Hz时，红外辐射计自身的NETD在MWIR(mid-wavelength infrared )、LWIR(long wavelength infrared)波段均小于0.01℃,能够满足热像仪测试设备校准需要。

In order to solve the calibration of the infrared imager test equipment, a kind of infrared radiometer in which the temperature of interior reference blackbody was equal to the environmental temperature was designed. In order to evaluate this kind of radiometer and give guidance to the infrared radiometer design, a mathematic model for infrared radiometer noise equivalent temperature difference （NETD）was given. The NETD of infrared radiometer was estimated under different electronic bandwidths and spectral wavebands. The results show that when noise equivalent bandwidth is within 1 Hz, NETD of infrared radiometer in mid-wavelength infrared (MWIR) and long wavelength infrared (LWIR) spectral bands is smaller than 0.01℃, which can meet the requirements of the calibration of infrared imager test equipment.