Juno is a spacecraft in polar orbit around Jupiter, and one of its objectives is to explore the Jovian magnetosphere. Charged particles trapped along the Jovian magnetic field lines may generate auroral emission. The Juno magnetospheric payload is designed to measure the charged particle distributions in the Jovian magnetosphere while remote sensing the related UV-auroral emissions. The ultraviolet spectrograph on Juno (Juno-UVS) is a photon-counting imaging spectrograph designed to observe Jupiter’s prominent far-UV auroral emissions in the 68 to 210 nm spectral range. This work presents an improvement on the wavelength and radiometric calibration of Juno-UVS. Ground calibration measurements were reanalyzed by expanding the spectral database ultimately used to produce the instrument spectral pixel size map. This significantly improves the wavelength assignation, up to 4 nm at the longer wavelengths, compared with the previous calibration. Dedicated Juno-UVS observation sequences were made to evaluate the slit-dependent radiometric calibration, which was revised accordingly. This work highlights a slight slit-dependent variation in the radiometric calibration. An additional radiometric correction was established at wavelengths greater than 160 nm using some of UVS’s brightest recorded stellar spectra.

中文翻译：

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更新了朱诺紫外光谱仪的辐射测量和波长校准

朱诺号是一艘绕木星极地轨道运行的航天器，其目标之一是探索木星磁层。沿木星磁场线捕获的带电粒子可能会产生极光发射。朱诺磁层有效载荷旨在测量木星磁层中的带电粒子分布，同时遥感相关的紫外线极光发射。朱诺号上的紫外光谱仪 (Juno-UVS) 是一种光子计数成像光谱仪，旨在观察木星在 68 至 210 纳米光谱范围内突出的远紫外极光发射。这项工作对 Juno-UVS 的波长和辐射校准进行了改进。通过扩展最终用于生成仪器光谱像素大小图的光谱数据库，对地面校准测量进行了重新分析。与之前的校准相比，这显着改善了波长分配，在更长的波长下可达 4 nm。制作了专用的 Juno-UVS 观测序列来评估依赖于狭缝的辐射校准，并相应地进行了修订。这项工作突出了辐射校准中与狭缝相关的轻微变化。使用一些 UVS 记录的最亮恒星光谱，在大于 160 nm 的波长处建立了额外的辐射校正。