Development of a NIR camera for the BALBOA mission
Abstract
More than 500 years ago, when Vasco Núñez de Balboa traveled to the New World, he must not have realized that his legacy would not only be cast in currency, but branded for space explorations. Our investigation and the pathfinder mission of BALloon-Based Observations for Sunlit Aurora is therefore named BALBOA, after this 15th-century Spanish explorer and conquistador. Since 1892, when an aurora was first imaged by Martin Brendel, a German physicist, auroral forms and their dynamics have been acquired only when the aurora is in darkness. Due to the sunlight contamination from Rayleigh scattering, it has been a long-term challenge of imaging sunlit aurora. In addition, other constraints exist, such as moonlight contamination, cloud occultation, and the limited land area available for installing imagers near the auroral zone in both hemispheres. While auroral imaging from space provides auroral global dynamics or small-scale structures, depending on the spacecraft orbit, the image quality is affected by low spatial and temporal resolutions, sunlight, and the lack of traceability of auroral variations (e.g., TIMED/GUVI, a spectrograph). Consequently, we have little knowledge of sunlit auroral forms and their dynamics, as well as their coupling to conjugate aurora. Given the fact that the solar wind-magnetosphere-ionosphere coupling is initiated on the dayside, understanding sunlit and dayside auroras becomes very interesting and important. A scenario of imaging sunlit aurora from a balloon and the conceptual design of the instrument have been depicted in our previous article Zhou et al. [2017]. The current paper elaborates the new science enabled by this new means and the feasibility of auroral ballooning by showing auroral images obtained from a recent balloon flight when the Sun was ~10° above horizon. We also discuss the corresponding sky brightness based on calculations using the MODTRAN6 model. In addition, we present some results of the instrument development, including the most important specs of the new InGaAs camera-head and some ground-based tests. The project is currently supported by the NASA/LCAS (Low Cost Access to Space) program.
- Publication:
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43rd COSPAR Scientific Assembly. Held 28 January - 4 February
- Pub Date:
- January 2021
- Bibcode:
- 2021cosp...43E2316Z