Pre-Launch Development of Sentinel-3 SLSTR Active Fire Product

海洋和陆地表面温度辐射计（SLSTR）是2013年至2025年期间在Sentinel-3卫星上飞行的欧空局新仪器。Sentinel-3是一个海洋和中分辨率陆地使命，主要致力于提供数据，以推动全球环境与安全监测（GMES）业务服务，并为科学应用提供不变的数据。SLSTR建立在传统的（A）ATSR系列仪器的基础上，具有对地球海洋，陆地表面和大气进行长期，高辐射性能观测的独特能力。然而，SLSTR从一开始就专门设计用于对海洋、大气和陆地进行高质量的观测，包括与活跃燃烧的火灾有关的观测。活动火信息是全球气候观测系统（GCOS）指定的基本气候变量（ECV）之一，用于支持对土地变化动态及其对气候的影响进行一致的全球监测，以便适当更新UNFCCC的气候变化估计。植被火灾被认为每年向大气中排放的碳量估计约为化石燃料燃烧的40%，这一事实说明了其重要性。全球气候观测系统实施计划是实施联合国公约的最先进的地球观测框架。该计划强调需要对陆地领域的13个基本气候变量（ECV）进行业务观测，其中包括火扰。有鉴于此，SLSTR仪器的一些规格已特别适用于提供必要的辐射观测，以提供有效的信息，超过活跃的火灾位置，最重要的是，包括两个新的辐射“火”通道集中在3.7微米和10.8微米，具有低增益，宽动态范围设置，防止饱和，即使是最激烈的燃烧火灾。因此，SLSTR有能力在全球范围内提供第一个可用的主动消防产品。该提案旨在通过开发，评估和测试一系列必要的算法来最大限度地提高英国和欧空局在SLSTR上的投资的科学效益和回报，以提供该仪器的优化，高质量的Active Fire产品，包括火灾位置，时间和火灾辐射功率（FRP）输出量化的不确定性。根据这一信息，可以计算植被燃料消耗率、碳、痕量气体和气溶胶释放率，以及沿着得出的其他参数。预计应用这些算法产生的业务产品将用于全球环境与安全监测业务服务（如设想从欧洲经委会主导的全球环境监测系统项目发展的大气服务）和英国气象局等国家机构，以及广泛的科学应用，包括与碳循环科学和大气成分研究有关的科学应用。业务机构目前在欧洲和非洲使用PI开发的对地静止动态火和玻璃钢产品，证明了这种数据对于近实时羽流预测的价值，例如与空气质量警报有关的数据。如果没有时间和必要的支持来开发和测试一套专门针对SLSTR的算法，任何由该仪器测量的辐射率得出的火灾产物都将局限于为其他传感器开发的现有算法的端口，因此将无法利用SLSTR的独特能力[例如其双视图能力和适应火灾的光谱通道]及其在哨兵上的位置，3颗卫星携带一套补充仪器。这个NCEO使命支持项目将确保我们有能力从SLSTR提供最佳的主动火灾信息，用于科学应用和业务服务。

The Sea and Land Surface Temperature Radiometer (SLSTR) is a new ESA instrument flying on the Sentinel-3 satellites from 2013 to 2025. Sentinel-3 is an Ocean and Medium-Resolution Land Mission primarily dedicated to delivering data to drive Global Monitoring for Environment and Security (GMES) Operational Services, as well as providing invariable data for science applications. SLSTR builds on the heritage (A)ATSR series of instruments, having unique capabilities for long-term, high radiometric performance observation of Earth's oceans, land surface and atmosphere. However, SLSTR has been designed from the start specifically to make high quality observations of the ocean, atmosphere and land, including in relation to actively burning fires. Active Fire information is one of the Essential Climate Variables (ECVs) designated by the Global Climate Observing System (GCOS) as required for supporting consistent global monitoring of land change dynamics and their impacts on climate, in order that climate change estimates for the UNFCCC maybe properly updated. The importance is illustrated by the fact that vegetation fires are believed to emit an annual amount of carbon to the atmosphere that is estimated as perhaps 40% of that due to fossil fuel burning. The Implementation Plan of GCOS is the most advanced Earth Observation framework for implementing a UN convention. The plan emphasizes the need for operational observations for thirteen Essential Climate Variables (ECV) in the terrestrial domain; among them Fire Disturbance. In view of this, a number of the specifications of the SLSTR instrument have been especially adapted for providing the necessary radiometric observations for delivering useful information over active fire locations, most importantly the inclusion of two new radiometric 'fire' channels centered on 3.7 microns and 10.8 microns that have low-gain, wide dynamic range settings that prevent saturation over even the most intensely burning fires. SLSTR therefore has the capability to deliver the first operational active fire product available at the global scale. The proposal aims to maximize the scientific benefit and the return on UK and ESA investment in SLSTR by developing, evaluating and and testing the series of algorithms necessary to deliver an optimized, high quality Active Fire product from this instrument, including fire location, time and fire radiative power (FRP) output with quantified uncertainties. From this information rates of vegetation fuel consumption, carbon, trace gas and aerosol release can be calculated, along with other subsequently derived parameters. It is expected that an operational product resulting from application of these algorithms would find use in both operational GMES Services, such as the Atmospheric Service envisaged as developing from the current ECMWF-led GEMS project, and by National Agencies such as the UK Met Office, and in a wide variety of science applications including those related to carbon cycle science and studies of atmospheric constituents. Current use by operational agencies of geostationary Active Fire and FRP products developed by the PI over Europe and Africa have demonstrated the value of such data for near-real time plume forecasting in relation to air quality warnings for example. Without the time and support necessary to develop and test a suite of algorithms specifically for SLSTR, any fire product derived from the radiances measured by the instrument will be limited to ports of existing algorithms developed for other sensors and so will fail to make use of the unique capabilities of the SLSTR [such as its dual view capability and fire-adapted spectral channels] and its position on the Sentinel-3 satellite carrying a suite of complementary instruments. This NCEO Mission Support project will ensure our ability to deliver optimum active fire information from SLSTR for use in both science applications and operational services.