VIIRS/NPP Thermal Anomalies/Fire 6-Min L2 Swath 750m NRT - V2

The VIIRS/NPP Thermal Anomalies/Fire 6-Min L2 Swath 750m NRT product, short-name VNP14_NRT is based on the MODIS Fire algorithm. The input to the Active Fires production are Level-1B moderate-resolution reflective band M7, and emissive bands M13 and M15. The fire algorithm first calculates bands M13, M15 brightness temperature (BT) statistics for a group of background pixels adjacent to each potential fire pixel. These statistics are used to set thresholds for several contextual fire detection tests. There is also an absolute fire detection test based on a pre-set M13 BT threshold. If the results of the absolute and relative fire detection tests meet certain criteria, the pixel is labeled as fire. The designation of a pixel as fire from the results of the BT threshold tests may be overridden under sun glint conditions or if too few pixels were used to calculate the background statistics.

The VNP14_NRT product contains several pieces of information for each fire pixel: pixel coordinates, latitude and longitude, pixel M7 reflectance, background M7 reflectance, pixel M13 and M15 BT, background M13 and M15 BT, mean background BT difference, background M13, M15, and BT difference mean absolute deviation, fire radiative power, number of adjacent cloud pixels, number of adjacent water pixels, background window size, number of valid background pixels, detection confidence, land pixel flag, background M7 reflectance, and reflectance mean absolute deviation.

The product provides day and nighttime active fire detection over land and water (from gas flares). The VNP14 product provides fire data continuity with NASA's EOS MODIS 1 km fire product.

For more information visit University of Maryland VIIRS Active Fire Web page at http://viirsfire.geog.umd.edu/

基于MODIS火灾算法的VIIRS/NPP热异常/火灾6分钟L2条带750米NRT产品，简称VNP14_NRT，其输入数据包括一级B级中分辨率反射波段M7，以及发射波段M13和M15。火灾算法首先针对每个潜在火灾像素邻近的背景像素组，计算M13、M15亮度温度（BT）的统计信息。这些统计信息被用于设置多个情境火灾检测测试的阈值。此外，还有一个基于预设M13 BT阈值的绝对火灾检测测试。如果绝对和相对火灾检测测试的结果满足特定标准，则该像素被标记为火灾。在太阳光反射条件下或背景统计像素过少时，可能根据亮度温度阈值测试结果覆盖像素的火灾标记。VNP14_NRT产品包含每个火灾像素的若干信息：像素坐标、纬度和经度、像素M7反射率、背景M7反射率、像素M13和M15 BT、背景M13和M15 BT、平均背景BT差异、背景M13、M15和BT差异的均方根绝对偏差、火灾辐射功率、相邻云像素数量、相邻水像素数量、背景窗口大小、有效背景像素数量、检测置信度、陆地像素标志、背景M7反射率和反射率均方根绝对偏差。该产品提供陆地和水面（来自气体火炬）的昼夜活动火灾检测。VNP14产品与NASA的EOS MODIS 1公里火灾产品提供火灾数据连续性。如需更多信息，请访问马里兰大学VIIRS活动火灾网页：http://viirsfire.geog.umd.edu/。