Burn Scar - Corrected Reflectance (VIIRS / NOAA-20)

Visualization Overview This visualization represents a global "false color" band combination (Red = M11, Green = I2, Blue = I1) of data collected by the VIIRS instrument on NOAA’s Joint Polar Satellite System (JPSS-1) satellite, which was renamed to NOAA-20 once on orbit. The intended use of the imagery is for distinguishing burn scars from naturally low vegetation or bare soil and enhancing floods. At its highest resolution, this visualization represents the underlying data scaled to a resolution of 250m per pixel at the equator. The VIIRS Corrected Reflectance product retains visible aerosols for a natural-looking visualization, though gross atmospheric effects (e.g. Rayleigh scattering) have been removed. The following guidelines will aid in understanding this visualization. See here for additional information on how this "false color" band combination highlights these physical characteristics of the Earth. Vegetation will appear bright green. Naturally bare soil, like a desert, will often appear to have a pinkish tinge. Burned areas (a.k.a. "burn scars") will appear as deep or bright red, depending on the type of vegetation burned, the amount of residue, or the completeness of the burn. Liquid water on the ground will appear dark blue while ice and snow will appear as bright turquoise. Clouds lower to the ground will appear white while high, and cold, clouds will appear turquoise. Multi-Spectral Bands The following table lists the VIIRS bands that are utilized to create this visualization. See here for a full description of all VIIRS bands. Band Description Wavelength (µm) Resolution (m) I1 Visible / Reflective (Red) 0.60 - 0.68 375 I2 Near IR (Green) 0.85 - 0.88 375 M11 Shortwave IR 2.23 - 2.28 750 Temporal Coverage and Limitations of Use By default, this layer will display the imagery currently available for today’s date. The update frequency is a "daily composite" that is assembled from hundreds of individual data files. When viewing imagery for “today,” you may notice that only a portion of the map has imagery. This is because the visualization is continually updated as the satellite collects more data. To view imagery over time, you can update the layer properties to enable time animation and configure time settings. Vintage: currently, this layer is available from present back to April 25th, 2020. In the coming months, this will be extended to the start of the mission (November 18th, 2017). Source: NASA Global Imagery Browse Services (GIBS), NASA Worldview, & NASA LANCE This visualization is provided through the NASA Global Imagery Browse Services (GIBS), which are a set of standard services to deliver global, full-resolution satellite imagery for hundreds of NASA Earth science datasets and science parameters. Through its services, and the NASA Worldview client, GIBS enables interactive exploration of NASA's Earth imagery for a broad range of users. The data and imagery are generated within 3 hours of acquisition through the NASA LANCE capability. Esri and NASA Collaborative Services This visualization is made available through an ArcGIS image service hosted on Esri servers and facilitates access to a NASA GIBS service endpoint. For each image service request, the Esri server issues multiple requests to the GIBS service, processes and assembles the responses, and returns a proper mosaic image to the user. Processing occurs on-the-fly for each and every request to ensure that any update to the GIBS imagery is immediately available to the user. As such, availability of this visualization is dependent on both the Esri and the NASA GIBS services.可视化概览 本可视化呈现的是搭载于美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration，NOAA）联合极地卫星系统（Joint Polar Satellite System，JPSS-1，入轨后更名为NOAA-20）的可见光红外成像辐射仪（Visible Infrared Imaging Radiometer Suite，VIIRS）所采集数据的全球“假彩色”波段组合（红色通道为M11，绿色通道为I2，蓝色通道为I1）。 该影像的设计用途为区分火烧迹地与天然低矮植被或裸土，并增强洪水的可视化效果。该可视化的原始数据在赤道处被缩放至每像素250米的最高分辨率。 VIIRS校正反射率产品保留了可见气溶胶以呈现自然的可视化效果，但已去除显著大气效应（如瑞利散射）。以下指南将帮助您理解该可视化效果。点击此处了解更多关于该“假彩色”波段组合如何凸显地球物理特征的信息。 植被将呈现亮绿色；天然裸土（如沙漠）通常会带有淡粉色调；烧过的区域（亦称“火烧迹地”）将呈现深红色或亮红色，具体取决于被烧毁的植被类型、残留量或燃烧完全度。地面液态水呈深蓝色，而冰雪则呈亮青蓝色。低空云呈白色，高空冷云则呈青蓝色。 多光谱波段 下表列出了用于生成本可视化的VIIRS波段。点击此处可查看所有VIIRS波段的完整说明。 | 波段 | 描述 | 波长（μm） | 分辨率（m） | |------|------|------------|------------| | I1 | 可见光/反射波段（红色通道） | 0.60 - 0.68 | 375 | | I2 | 近红外波段（绿色通道） | 0.85 - 0.88 | 375 | | M11 | 短波红外波段 | 2.23 - 2.28 | 750 | 时间覆盖范围与使用限制 默认情况下，该图层将显示当前日期可用的最新影像。其更新频率为“每日合成”，由数百个独立数据文件拼接而成。当查看“今日”影像时，您可能会发现地图仅有部分区域覆盖影像，这是因为该可视化会随着卫星采集更多数据而持续更新。若要查看随时间变化的影像，您可以更新图层属性以启用时间动画并配置时间设置。 数据时效：当前该图层的可用时间范围为当前至2020年4月25日。未来数月内，该时间范围将扩展至任务起始日（2017年11月18日）。 数据来源 本可视化通过NASA全球影像浏览服务（Global Imagery Browse Services，GIBS）、NASA Worldview与NASA LANCE提供。 NASA全球影像浏览服务（GIBS）是一套标准服务，可为数百个NASA地球科学数据集与科学参数提供全球全分辨率卫星影像。通过其服务与NASA Worldview客户端，GIBS可为广大用户提供交互式探索NASA地球影像的功能。通过NASA LANCE功能，数据与影像可在采集后3小时内生成。 Esri与NASA联合服务 本可视化通过托管于Esri服务器的ArcGIS影像服务提供，该服务可对接NASA GIBS服务端点。每一次影像服务请求，Esri服务器都会向GIBS服务发起多次请求，处理并拼接响应结果，最终向用户返回完整的镶嵌影像。所有请求均会实时处理，以确保GIBS影像的任何更新都能立即对用户可见。因此，本可视化的可用性同时依赖于Esri与NASA GIBS两项服务。