Both NASA’s VERITAS and ESA’s EnVision missions to Venus incorporate a Venus Emissivity Mapper (VEM) to characterize the surface and distinguish basalt from more felsic rock types. Though Venus’ optically dense atmosphere makes direct observations of the surface challenging, five windows in the CO2 spectrum near 1 μm will be exploited by the VEM instrument. In preparation for these missions, an analog of the VEM instrument (VEMulator2.0) was constructed for field measurements. It was used in a two-week field campaign at Venus-analog sites in Iceland in August 2023 as part of a VERITAS field campaign to collect multi-frequency reflectance measurements of volcanic rocks of varying age and surface conditions, as well as to measure emission from recently erupted lava with hot spots up to ~400°C. The goal of the work was to train scientists and to help assess the capability of the VEM instrument to detect differences in surface composition in a wide variety of volcanic rocks in the field with the limited spectral information provided by six bands. In addition, samples of the imaged regions were collected to be analyzed in detail at the Planetary Spectroscopy Laboratory at DLR in Berlin. Comparing field and laboratory spectra gives insights into the efficacy and limitations of the analog instrument. This paper describes the emulator design and calibration procedure as well as first results from field and laboratory measurements.
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 "VEM emulator" (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.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.