Designing iterations of the Venus Emissivity Mapper Emulator: making a space instrument suitable for field campaigns

Abstract

One of the main objectives of the NASA's VERITAS and the ESA's EnVision missions is to characterize the composition and origin of the major geologic terrains on Venus. Both missions carry the Venus Emissivity Mapper (VEM) – a multispectral imager - which will be able to observe the surface of Venus through five atmospheric windows with six bands, around the 1µm spectral range. This will enable the spectral characterization of the Venusian surface, as well as deduce the type of lava and likely alteration processes, providing new insights into the evolution of Venus. To improve our knowledge of the mineralogical information obtained from the 1µm spectral range, we are developing a series of "VEMemulator" (aka VEMulator). The first one was based on a commercial Raspberry PI HQ 12MP camera, containing the Sony IMX477 sensor, with a 35mm lens. Four filters with wavelengths of 860, 910, 990, 1100 nm could be attached in front of the lens similar to four of the six VEM mineralogy spectral bands. This instrument was deployed in summer 2022 on the Vulcano island in southern Italy as Venus analog site. Vulcano rocks display a diverse compositional variation from basaltic to rhyolitic, which makes this site an attractive analog to Venus. Currently, a new version of the VEMulator is being developed using the SCD Cardinal 1280 InGaAs detector – similar to the detector used in the VEM flight model. This VEMulator 2.0 will be used in Iceland, in 2023, for a VERITAS field campaign.