Emirates Mars Mission 2020: Emirates eXploration Imager (EXI) Overview

Abstract:

The Emirates eXploration Imager (EXI) instrument is one of three scientific instruments aboard the Emirate Mars Mission (EMM) spacecraft, “Hope”. With a planned arrival at Mars of February 2021 (check date), the goal of this United Arab Emirates (UAE) mission is to explore the dynamics of the Martian atmosphere through global spatial sampling that captures both diurnal and seasonal timescales. A particular focus of the mission is the circulation of the lower atmosphere and the connections to the upward transport of energy of the escaping atmospheric particles from the upper atmosphere. This will be accomplished using three complementary scientific instruments. The subject of this presentation, EXI, is a multi-band, camera capable of taking 12- megapixel images, which translates to a spatial resolution of better than 10 km, with a well characterized radiometric performance. EXI employs a filter-wheel mechanism consisting of 6 discrete bandpass filters that sample the optical spectral region: 3 UV bands and 3 visible (RGB) bands. Atmospheric characterization will involve the retrieval of the ice optical depth from the 300–340 nm band and the column abundance of ozone using a band covering 245–275 nm. Radiometric fidelity is optimized while simplifying the optical design by separating the UV and VIS optical paths. The instrument is being developed jointly by the Mohammed Bin Rashid Space Centre (MBRSC), Dubai, UAE, and the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado, Boulder, USA. The ground-calibration efforts of the instrument occurred in Spring 2019, and included the following tests, Field of View Mapping (FOV), Focus/distortion mapping, Flat field/Broadband radiometry, Bandpass shape/Absolute radiance mapping. The results of these calibration activities and an instrument status update will be the focus of our presentation.