原文连接：http://scienceandglobalsecurity.org/archive/sgs12wilkening.pdf
Infrared ballistic missile early-warning satellites such as the Defense SupportProgram (DSP) and its future replacement, SBIRS-High, are candidates for missile detection and tracking. The Space-Based Infra-Red System-Low EarthOrbit (SBIRS-Low) is not expected to play a significant role in boost-phase defense because its multi-spectral optical system, particularly its long-waveinfrared sensor, is designed to accurately track objects against the cold background of outer space and, hence, cannot observe missiles until relatively latein their boost phase. Moreover, due to significant cost overruns, it is not clear when SBIRS-Low will be deployed, if ever.
This analysis assumes that a sensor like SBIR-High will be deployedto support boost-phase ballistic missile defense. The capability of a notional space-based infrared system like SBIRS-High has been examined in a recent American Physical Society (APS) study.7 This detector consists of a 30 cm telescope with a HgCdTe focal plane array that stares at 1/24 of the Earth’s surface every 33 msec, thus scanning the entire surface in less than one second unless it focuses intentionally on a narrow region of high interest. The APS study assumed that this sensor operated in one of the infrared atmospheric windows (e.g., 2.0–2.5 μm or 3.5–5 μm) as opposed to an infrared absorption band likeDSP, thereby allowing the sensor to see down to the Earth’s surface under clear conditions, with a 1 km× 1 km pixel footprint at the Earth’s surface.
