Abstract. The NOAA-20 Visible Infrared Imaging Radiometer Suite (VIIRS) instrument has been successfully operating on orbit since November 28, 2017. The day–night band (DNB) onboard NOAA-20 VIIRS is a panchromatic channel covering wavelengths from 0.5 to 0.9 μm, capable of observing the Earth scene in visible/near-infrared spectral range at a spatial resolution of 750 m. The DNB operates at low-, mid-, or high-radiometric gain stages, and it uses an onboard solar diffuser (SD) panel for low-gain stage calibration. The SD observations also provide a means to compute gain ratios between low-to-mid and mid-to-high-gain stages. With their large dynamic range and high sensitivity, the DNB detectors can make observations during both daytime and nighttime. We provide an assessment of the DNB on-orbit performance and behavior in the first two-year mission period and beyond. The calibration methodology used by the VIIRS Characterization Support Team in support of the NASA Earth science community has been described. The trending of on-board calibrators dark-offsets, SD gains, and gain ratios, and signal-to-noise ratio at minimum radiance have been analyzed, especially during key events such as the nadir and cryocooler doors opening. Furthermore, we performed intercomparison studies between Suomi National Polar-orbiting Partnership and NOAA-20 instruments and evaluated DNB radiometric calibration and characterization, including the SD degradation, detector gains, gain ratios, and straylight correction, as well as the calibration comparison between the NOAA Interface Data Processing Segment look-up-tables and our delivery results.

中文翻译：

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NOAA-20 可见红外成像辐射计套件日-夜波段在轨校准和性能

摘要。NOAA-20 可见红外成像辐射计套件 (VIIRS) 仪器自 2017 年 11 月 28 日起在轨道上成功运行。 NOAA-20 VIIRS 上的昼夜波段 (DNB) 是一个全色通道，覆盖波长从 0.5 到 0.9 μm，能够以 750 m 的空间分辨率在可见光/近红外光谱范围内观察地球场景。DNB 在低、中或高辐射增益级运行，并使用板载太阳能扩散器 (SD) 面板进行低增益级校准。SD 观测还提供了一种计算中低增益级和中高增益级之间增益比的方法。凭借其大动态范围和高灵敏度，DNB 探测器可以在白天和夜间进行观测。我们提供对 DNB 在头两年任务期间及以后的在轨性能和行为的评估。VIIRS 表征支持团队为支持 NASA 地球科学界而使用的校准方法已被描述。已经分析了板载校准器暗偏移、SD 增益和增益比以及最小辐射时的信噪比的趋势，特别是在诸如最低点和低温冷却器门打开等关键事件期间。此外，我们在 Suomi National Polar-orbiting Partnership 和 NOAA-20 仪器之间进行了比对研究，并评估了 DNB 辐射校准和表征，包括 SD 退化、探测器增益、增益比和杂散光校正，