Early Concept for New Mission: A Spaceborne Multispectral Canopy Lidar

新任务的早期概念：星载多光谱冠层激光雷达

• 批准号: NE/H004106/1
• 负责人: David Henry
• 金额: $ 2.4万
• 依托单位: UK Astronomy Technology Centre
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2010
• 资助国家: 英国
• 起止时间: 2010 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FH004106%2F1
• 关键词: Early; Concept; New; Mission; Spaceborne

Our Aim This project aims to develop and design a new satellite mission. This new mission concept will be a spaceborne multispectral canopy lidar (called SpeCL, 'speckle') that can measure the vertical profile of a forest and simultaneously determine the spectral characteristics of that profile. Since lidars can provide highly detailed 3D information on the structure of forest they have great potential in reducing the uncertainties in the terrestrial carbon cycle and of supporting the accurate mapping of land cover. The primary scientific objective of the SpeCL mission would be to determine the global distribution of above ground biomass in the world's forests using an appropriate sampling strategy, and to reduce uncertainties in the calculations of carbon stocks and fluxes associated with the terrestrial biosphere. Why is this important? Greenhouse gases associated with forestry (deforestation and degradation) accounts for roughly 17% of global emissions, more than the entire global transport network. A recent report to the Prime Minister (the 2008 Eliasch Review on Financing Global Forests) predicts that without action, the global economic cost of climate change caused by deforestation alone could reach $1 trillion a year by 2100. Most emissions of carbon from land-use change are currently from the tropics as a result of deforestation, which releases the carbon stored in biomass and soils to the atmosphere (as CO2) as organic matter is burned or decays. The regular monitoring and assessment of land cover change is therefore essential to understand the extent and impact of natural and anthropogenic changes Furthermore, analysis of the global carbon cycle shows that the annual emissions of carbon are larger than the annual accumulations of carbon in the atmosphere and oceans, suggesting a terrestrial sink for carbon in addition to that attributable to changes in land use. Remarkably, this as yet unexplained residual sink seems to have increased over the last decades in proportion to total carbon emissions, implying that carbon feedbacks are offsetting each other. This balance is unlikely to persist. The SpeCL mission is an opportunity to constrain both the net emissions of carbon from land-use/land-use change, and the residual terrestrial sink. Any further delay in understanding the carbon budget may have serious long term consequences if we leave too little time to respond. How will we do it? Edinburgh has pioneered the development of the world's first Multi Spectral Canopy Lidar (patent number 0808340.4). Using seedcorn funding from CEOI, we built the first 4-wavelength lidar, demonstrated its use in the lab and modelled the seasonal response. An airborne MSCL (A-MSCL) instrument has been designed and proposed to NERC on July 1st. In anticipation of future mission opportunities (and the long lead time required), there exists an imminent need for determining the feasibility and technical readiness of a spaceborne MSCL. In the first instance we will create a concept for the high cost, but low risk option of a traditional small satellite configuration with a cost ceiling of £100M. We will then aim to develop this concept to an ultra-low cost (<£5M), rapid deployment (within 3 years) micro-satellite platform using off-the-shelf components and where appropriate, 'proved' technologies. To this end we will consider the highly novel, high risk, but very low cost option of using a modular CubeSat platform.

该项目旨在开发和设计一种新的卫星使命。这一新的使命概念将是一个星载多光谱冠层激光雷达（称为SpeCL，“斑点”），它可以测量森林的垂直剖面，同时确定该剖面的光谱特征。由于激光雷达可以提供关于森林结构的非常详细的三维信息，它们在减少陆地碳循环的不确定性和支持精确绘制土地覆盖图方面具有巨大潜力。SpeCL使命的主要科学目标是利用适当的取样战略确定世界森林地上生物量的全球分布，并减少与陆地生物圈有关的碳储存和通量计算中的不确定性。为什么这很重要？与森林有关的温室气体（森林砍伐和退化）约占全球排放量的17%，超过整个全球交通网络。最近提交给总理的一份报告（《2008年全球森林筹资Eliasch审查》）预测，如果不采取行动，到2100年，仅森林砍伐造成的气候变化的全球经济成本就可能达到每年1万亿美元。目前，土地使用变化产生的大部分碳排放来自热带地区，原因是森林砍伐，随着有机物燃烧或腐烂，生物质和土壤中储存的碳（以二氧化碳形式）释放到大气中。因此，定期监测和评估土地覆被变化对于了解自然和人为变化的程度和影响至关重要。此外，对全球碳循环的分析表明，每年的碳排放量大于每年在大气和海洋中的碳积累量，这表明，除了土地利用变化造成的碳汇外，还有一个陆地碳汇。值得注意的是，在过去的几十年里，这种尚未解释的残余汇似乎与总碳排放量成比例地增加，这意味着碳反馈正在相互抵消。这种平衡不太可能持续下去。SpeCL使命是限制土地利用/土地利用变化产生的碳净排放和剩余陆地汇的机会。如果我们留给应对的时间太少，那么在理解碳预算方面的任何进一步拖延都可能产生严重的长期后果。我们要怎么做？爱丁堡率先开发了世界上第一台多光谱冠层激光雷达（专利号0808340.4）。利用CEOI提供的种子资金，我们建造了第一台4波长激光雷达，在实验室中演示了它的使用，并对季节性响应进行了建模。设计了一种机载MSCL（A-MSCL）仪器，并于7月1日提交给NERC。考虑到未来的使命机会（以及所需的较长准备时间），迫切需要确定星载MSCL的可行性和技术准备情况。首先，我们将为传统小型卫星配置的高成本但低风险选项创建一个概念，成本上限为1亿英镑。然后，我们的目标是将这一概念发展成为一个超低成本（<500万英镑），快速部署（3年内）的微型卫星平台，使用现成的组件和适当的“成熟”技术。为此，我们将考虑使用模块化CubeSat平台的高度新颖、高风险但成本非常低的选择。