Measurements by the REMS/UV sensor onboard the MSL Curiosity rover constitute the first in situ dataset of UV radiation flux at the surface of Mars. Due to its position on the Curiosity deck, the UV sensor has been directly exposed to dust deposition. Inaccuracies in the original angular response calibration functions have led to discrepancies between measured and physically-expected UV fluxes when the solar zenith angle ( $\theta $ ) relative to the rover frame is between $20^{\circ}$ and $55^{\circ}$ . Here we present a methodology to correct UV fluxes when $\theta < 55^{\circ}$ for both effects, and show results of the corrected data set for the first 2003 sols (∼3 Martian Years, MY) of the MSL mission, from L $_{\mathrm{s}} \sim 151^{\circ}$ in MY 31 to L $_{\mathrm{s}} \sim 149^{\circ}$ in MY 34. Close to noon, when $\theta $ values are typically < $30^{\circ}$ , relative differences between corrected and original UV fluxes are ∼35 – 40% on average. Outside hours close to noon, when $\theta $ is typically > $30^{\circ}$ , relative differences are greater than 100%. Measurements acquired when $20^{\circ}$ < $\theta < 55^{\circ}$ represent ∼45% of the whole dataset with $\theta < 90^{\circ}$ . UV fluxes generated in this study are available in the NASA Planetary Data System ( https://atmos.nmsu.edu/PDS/data/mslrem_1001/DATA_UV_CORRECTED/ ), and are important to study the effect of UV radiation on the variability of atmospheric constituents, to recreate accurate UV doses for biological laboratory experiments, to perform combined analyses of satellite and ground-based measurements, and to allow comparisons of the UV radiation environment at different locations with the upcoming ExoMars 2020 and Mars 2020 missions.

中文翻译：

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通过 MSL/REMS 进行原位紫外线测量：灰尘沉积和角响应校正

MSL 好奇号火星车上的 REMS/UV 传感器的测量构成了火星表面紫外线辐射通量的第一个原位数据集。由于其在好奇号甲板上的位置，紫外线传感器直接暴露在灰尘沉积中。当太阳天顶角 ($\theta $) 相对于漫游车框架在 $20^{\circ}$ 和 $55^{\ 之间时，原始角响应校准函数的不准确导致测量的和物理预期的紫外线通量之间存在差异圆}$。在这里，我们提出了一种方法，用于在 $\theta < 55^{\circ}$ 时校正两种效应的紫外线通量，并显示 MSL 任务的第一个 2003 年溶胶（~3 火星年，MY）的校正数据集的结果，从 MY 31 中的 L $_{\mathrm{s}} \sim 151^{\circ}$ 到 MY 34 中的 L $_{\mathrm{s}} \sim 149^{\circ}$。接近于中午，当 $\theta $ 值通常 < $30^{\circ}$ 时，校正后的和原始的紫外线通量之间的相对差异平均约为 35 – 40%。在接近中午的时间之外，当 $\theta $ 通常 > $30^{\circ}$ 时，相对差异大于 100%。当 $20^{\circ}$ < $\theta < 55^{\circ}$ 代表整个数据集的 ~45% 时获得的测量值， $\theta < 90^{\circ}$ 。本研究中产生的紫外线通量可在 NASA 行星数据系统 (https://atmos.nmsu.edu/PDS/data/mslrem_1001/DATA_UV_CORRECTED/) 中获得，并且对于研究紫外线辐射对大气变化的影响很重要成分，为生物实验室实验重建准确的紫外线剂量，对卫星和地面测量进行组合分析，