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

点击翻译按钮获取中文摘要

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.