关键词：图像;毫米波;方程;数学;灵敏度;信噪比
摘 要：The phenomenology of imaging in the millimeter-wave (MMW) and submillimeter-wave (SMMW)/terahertz (THz) frequency regimes is investigated and described. The primary factors related to imaging in these frequency regimes are phenomenologically driven and involve trade-offs between spatial (angular) resolution; the impact of atmospheric and obscurant attenuations such as fog, dust, and concealing materials; and system sensitivity requirements. Minimum system sensitivity requirements for adequate imaging in three important military/security scenarios are identified and described in terms of minimum apparent temperature differences between targets and their backgrounds. Mathematical equations for calculating the minimum system sensitivity (noise equivalent power NEP) per root hertz (Hz) required to provide image frames with enough signal-to-noise ratio (SNR) to produce good imagery at video frame rates are derived.