New methods for remote sensing of vegetated ecosystems: in situ measurement and multi-scale mapping

拟议的研究方案的中心是开发利用遥感工具对植被生态系统(林地和湿地)进行调查或绘制地图的方法。有两个具体目标，第一个目标是改进现有技术和利用遥感工具开发新的现场测量方法。现场测量方法提供深度测量，但在有限数量的采样区域上。库存数据集的频繁空白提高了利用遥感工具进行新的衡量替代办法的重要性。在利用遥感测量植被生态系统方面，有三种工具特别有前景和创新：(1)半球摄影(HP)，(2)陆地激光雷达(TLiDAR)，和(3)植被冠层结构模型。它们提供了测量细节的分级：HP是树冠极平面上的2D表示，TLiDAR是树冠元素的显式3D探测，而树冠建筑模型是树冠的3D表示，可以扩展来自遥感传感器的测量。第二个具体目标是从多尺度数据的集成中发展植被生态系统制图方法。在使用植被生态系统的空间数据集时，尺度的分级通常起作用。就光学传感器而言，测量范围从地面地块到图像，从地方和区域测绘的高空间分辨率，到国家和全球测绘的最低空间分辨率。在我的研究计划中，我优先考虑地方(约10厘米至4米)或区域(约10米至100米)的地图绘制项目。关于在不同比例尺上使用空间数据集，需要解决许多问题：如何最好地利用地块数据培训制图方法？有哪些替代方案可以填补不同规模的数据缺口？如何整合非图像数据以改进生成的地图？除了具体的多比例尺项目外，我们还提出了一个促进地图绘制方法发展的总体框架。因此，我的研究计划提供了适用于植被生态系统中各种条件的测量和测绘解决方案。

The proposed research program is centered on the development of methods for inventory or mapping vegetated ecosystems (forestland and wetland) using remote sensing tools. There are two specific objectives targeted where the first one aims at improving existing techniques and developing new in situ measurement methods with remote sensing tools. In situ measurement methods provide in-depth measurements but on a limited number of sampled areas. Frequent gaps in inventory data sets raise the importance of new measurement alternatives with remote sensing tools. Three tools are particularly promising and innovative in the use of remote sensing for measurement of vegetated ecosystems: (1) hemispherical photography (HP), (2) terrestrial LiDAR (TLiDAR), and (3) model of vegetation canopy architecture. They provide a gradation of measurement details: HP is a 2D representation in polar plane of the canopy, TLiDAR is an explicit 3D sounding of canopy elements, and a canopy architecture model is a 3D representation of canopy that can extend the measure from remote sensing sensors. The second specific objective aims at developing mapping methods of vegetated ecosystem from integration of multi-scale data. A gradation of scales is usually at work in the use of spatial data sets for vegetation ecosystems. In the case of optical sensors, measurements span from ground plots towards imagery from high spatial resolution for local and regional mapping, and gradually towards the lowest spatial resolution for national and global mapping. In my research program I priorize mapping projects at either local (~10cm to 4m) or regional levels (~10m to 100m). Many questions need to be addressed concerning the use of spatial data sets at different scale: How best to use plot data to train mapping methods? What are the alternatives to fill data gaps at different scales? How to integrate non image data to improve resulting maps? Aside specific multi-scale projects, we propose an overall framework to facilitate development of mapping methods. My research program thus provides measurement and mapping solutions applicable to a wide range of conditions present in vegetated ecosystems.