VIIRS/JPSS2 Thermal Anomalies/Fire 6-Min L2 Swath 750m NRT - V2

The VIIRS/JPSS2 Thermal Anomalies/Fire 6-Min L2 Swath 750m NRT product, short-name VJ214_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 VJ214_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 VJ214 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 火焰算法的 VIIRS/JPSS2 热异常/火灾 6 分钟 L2 斜带 750 米近实时产品，简称 VJ214_NRT，其输入为一级B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相邻的一组背景像素，计算 M13、M15 亮度温度（BT）的统计值。这些统计值被用于设定多个上下文火灾检测测试的阈值。此外，还基于预设的 M13 BT 阈值进行绝对火灾检测测试。若绝对和相对火灾检测测试的结果符合特定标准，则该像素被标记为火灾。在阳光反射条件下或背景统计像素数量不足时，可能根据 BT 阈值测试结果对像素标记为火灾进行覆盖。VJ214_NRT 产品包含每个火灾像素的多个信息项：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 差异的平均绝对偏差、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 反射率以及反射率的平均绝对偏差。该产品提供陆地和水面上（来自气体火炬）白天和夜晚的主动火灾检测。VJ214 产品与 NASA 的 EOS MODIS 1 公里火灾产品提供火灾数据的连续性。欲了解更多信息，请访问马里兰大学 VIIRS 主动火灾网页：http://viirsfire.geog.umd.edu/。