Remote Sensing for Forestry Applications

The most exciting phrase to hear in science, the one that heralds new discoveries, is not Eureka! (I found it!) but rather, "hmm... that's funny...”

Isaac Asimov

Synthetic Aperture Radar for forest height inventory

Introduction

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Forest covers approximately 30% of the world land area, equating to 3,869 million hectares. It is of great importance that these ecosystems and vital resource can be assessed and monitored on a regular and frequent basis. Traditional forest inventory methods such as ground survey and aerial photographs are expensive and time consuming and therefore remote sensing techniques are seen as the required technology to aid foresters, conservation groups and government agencies. One of these technologies which has only recently reached the stage of potential operational application is Synthetic Aperture Radar (SAR). SAR, being an active remote sensing tool, transmits its own microwave signal and so, unlike other remote sensing tools, is independent of both light conditions and cloud cover. Thus giving the potential of 24-hour coverage. Traditional forest surveys involve intensive ground campaigns in conjunction with aerial photograph analysis. This process is time consuming and expensive. In the currencomparison to ground data. The ground data will be gathered from Glen Affric, Northern Scotland, and accuracies will be established between ground data and SAR measurements. Forest parameters of particular interest include area, species, height, structure and biomass.t forest economical market, financial burdens are a limiting factor for forest managers, planners and conservation groups. The use of remote sensing is seen as one area in which financial outlay can be used to gain maximum benefit. Larger areas can be covered rapidly, with increasing levels of data and accuracy obtainable. It is foreseen that forest management can be supported by the use of remote sensing, enabling a more efficient use of resources, and therefore a more sustainable forest industry, be it in terms of timber production, conservation, landscape or recreation. The current study is assessing the capabilities of Synthetic Aperture Radar (SAR) to provide useable forest management information. Two primary approaches are being assessed, firstly forest structure mapping, and secondly tree height estimation. The areas are being approached at the land-use, stand and sub-stand/tree scales. These parameters can then be used as inputs to standard forestry models to estimate realisable products such as timber volume, biomass, carbon content and biodiversity amongst others. This study forms part of a larger project entitled 'Retrieving tree height, species indicators and surface topography from polarimetric and interferometric Synthetic Aperture Radar' which is being conducted by the Edinburgh Earth Observatory, The University of Edinburgh. This study is aimed at providing useful parameters for use on future satellite-borne systems such as ALOS (Advanced Land Observing Satellite). The study also has links with 'The Glen Affric Project: Forest mapping using dual baseline polarimetric radar interferometry'. Supervisors: - Dr. Iain Woodhouse (Edinburgh Earth Observatory, School of GeoSciences, The University of Edinburgh) - Dr. Tim Malthus (Institute of Geography, School of GeoSciences, The University of Edinburgh) - Juan Suárez (Forest Research, Northern Research Station)

Research Interests	[top]
Remote Sensing, SAR, forestry, forest height inventory.

SAR for Forest Height Inventory

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The first aim is to examine the potential of SAR to estimate tree height. This investigation will evaluate SAR Interferometry to retrive tree height. A second aim of the study is to investigate microwave interaction with a forested landscape, and this will include comparison to models which are being developed as part of the larger project. The third aim will be to assess the use of radar (both airborne and satellite borne) for use in forest height inventory.

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