Reconstruction of forest dynamics using multi-temporal 3D remote sensing

利用多时相3D遥感重建森林动态

• 批准号: 184009-2006
• 负责人: StOnge, Benoit
• 金额: $ 1.44万
• 依托单位: Université du Québec à Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2007
• 资助国家: 加拿大
• 起止时间: 2007-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=364837
• 关键词: Reconstruction; forest; dynamics; using; multi

The general objective of this research program is to develop 3D remote sensing methods to map the height, density and biomass of the forest at different points in time in order to observe and measure changes in these attributes. We use scanning laser altimetry ("lidar") to precisely map the elevation of the ground under forest canopy, but also to measure the elevation of the forest canopy surface. By calculating the difference between these two surfaces, we can compute and map canopy height. The elevation of the canopy surface can also be retrieved through photogrammetric measurements performed on scanned aerial photos. Because archives of aerial photos exist since the 1920s, we can actually reconstruct changes in forest canopy height over several decades by combining photogrammetric measurements performed on old photos to recent lidar data describing the ground elevation. Within this project, we will use a time series of height maps created using this method for the period 1945-2003 to improve a forest growth model. By checking the model against what really happened in the past, we improve our capacity of predicting future changes. This project will also use lidar data acquired in 1998, 2003, and 2007 to improve this model because minutes changes can be better observed on lidar data. Finally, we will be testing a new type of lidar called "scanning full waveform lidar" to measure the structure of layers of trees hidden under the canopy surface. This will improve our capacity of mapping regeneration under the main canopy surface. The results from this research will generate new knowledge on forest dynamics, will improve our understanding of the rate of carbon sequestration in the forest biomass, and will help forest managers improve their forestry practices.

这项研究计划的总体目标是开发三维遥感方法，绘制不同时间点森林的高度、密度和生物量，以观察和测量这些属性的变化。我们使用扫描激光测高仪（“激光雷达”）精确地绘制森林树冠下地面的海拔，同时也测量森林树冠表面的海拔。通过计算这两个表面之间的差异，我们可以计算和绘制冠层高度。冠层表面的高程也可以通过对扫描的航空照片进行摄影测量来检索。由于自20世纪20年代以来就存在航空照片档案，因此我们实际上可以通过将旧照片上的摄影测量与描述地面高程的最新激光雷达数据相结合来重建几十年来森林树冠高度的变化。在这个项目中，我们将使用一个时间序列的高度图使用这种方法创建的1945年至2003年期间，以改善森林生长模型。通过将模型与过去实际发生的情况进行对比，我们可以提高预测未来变化的能力。该项目还将使用1998年、2003年和2007年获得的激光雷达数据来改进该模型，因为激光雷达数据可以更好地观察分钟变化。最后，我们会测试一种名为“扫描全波形激光雷达”的新型激光雷达，以测量隐藏在树冠表面下的树木层次结构。这将提高我们的能力下的主要冠层表面的更新绘图。这项研究的结果将产生关于森林动态的新知识，将提高我们对森林生物量中碳固存率的理解，并将帮助森林管理人员改善其林业实践。