摘要：The Longwave Infrared Camera (LIR) is one of a suite of cameras onboard the Venus orbiter Akatsuki.It will take images of thermal radiation in the wavelength range of 8–12 µm emitted by the Venus cloud tops.The use of an uncooled micro-bolometer array as an infrared image sensor makes LIR a lightweight, small and low-power consumption instrument with a required noise equivalent temperature difference of 0.3 K.Temperature and horizontal wind fields at the cloud-top will be retrieved for both dayside and nightside with equal quality.This will provide key observations to understand the mechanism of super rotation and the thermal budget of the planet.LIR will also monitor variations of the polar dipole and collar which are characteristic thermal features in the Venusian atmosphere.Mechanisms of the upper-cloud formation will be investigated using sequences of close-up images.The morphology of the nightside upper cloud will be studied in detail for the first time. Key words Venus Planet-C atmosphere.
