VIIRS/JPSS1 Day/Night Band 6-Min L1B Swath 750m NRT

The VIIRS Level 1 and Level 2 swath products are generated from the processing of 6 minutes of VIIRS data acquired during the Joint Polar Satellite System - 1 (JPSS1) satellite overpass. The Day/Night band (DNB) is a panchromatic channel covering the wavelengths from 500 nm to 900 nm, and sensitive to visible and near-infrared from daylight down to the low-level radiation observed at night.

The VIIRS DNB is much improved from previous products due in large part to its complicated continuous on-board calibration. In addition, new-moon Earth observations are used to estimate and remove stray light. These corrections are a first of its kind to provide on-orbit radiometric calibration. The corrections made to the DNB data are provided by the NASA VIIRS Characterization Support Team and are likely to continue to evolve given this new methodology.

The spatial resolution of the instrument at viewing nadir is approximately 750 m for the DNB and the Moderate-resolution Bands and and 375m for the Imagery bands. The DNB is aggregated to maintain nearly constant horizontal spatial resolution across the swath.

As the DNB is sensitive to nighttime radiation over the full lunar cycle, the incoming solar and lunar radiation must be properly modeled to calculate the reflectance. However, the DNB is sensitive to more sources of radiation than just the sun and moon.

VIIRS（ Visible Infrared Imaging Radiometer Suite）的1级和2级条带产品是通过联合极地卫星系统-1（Joint Polar Satellite System - 1，JPSS1）卫星过境期间获取的6分钟VIIRS数据加工而成的。日夜波段（Day/Night Band，DNB）是一个覆盖500 nm至900 nm波长的全色通道，对白昼及夜间低层辐射的可见光和近红外均具有敏感性。相较于前期产品，VIIRS DNB得到了显著提升，这主要得益于其复杂的连续在轨校准。此外，利用新月地球观测数据来估算和去除杂散光，这些校正措施首次实现了在轨辐射定标。对DNB数据进行校正的工作由NASA VIIRS特性支持团队提供，鉴于这一新方法，这些校正措施预计将持续演进。仪器在观测天顶时的空间分辨率约为750 m（DNB波段和中等分辨率波段）以及375 m（影像波段）。DNB被汇总以保持条带内近似的恒定水平空间分辨率。由于DNB对整个月相周期的夜间辐射敏感，因此必须对 incoming solar and lunar radiation 进行恰当的建模，以计算反射率。然而，DNB对辐射的敏感性不仅限于太阳和月亮。