ABSTRACT

Remote-sensing techniques, particularly using satellite remote-sensing techniques, offer a practical means to measure leaf area index (LAI) at a landscape or even global scale. This chapter provides an overview on using optical satellite remote-sensing techniques for estimating and mapping forest LAI. To estimate and map forest LAI, a wide range of analysis techniques and approaches that have been developed and demonstrated are reviewed. The spectral analysis techniques include spectral derivative analysis, vegetation

CONTENTS

10.1 Introduction .................................................................................226 10.2 Techniques and methods............................................................... 227

10.2.1 Statistical and empirical methods ...................................... 227 10.2.1.1 Derivative analysis ................................................ 230 10.2.1.2 Vegetation index analysis ..................................... 230 10.2.1.3 Spectral position variable analysis ........................ 231 10.2.1.4 Transformed feature extraction ............................ 234 10.2.1.5 Spectral mixture analysis ..................................... 236 10.2.1.6 Advanced statistical algorithms ............................ 237

10.2.2 Physically based modeling inversion techniques ................. 238 10.3 Estimating and mapping LAI with multisatellite sensors and

systems ......................................................................................... 240 10.3.1 With moderate resolution data ........................................... 240 10.3.2 With high resolution data .................................................. 244 10.3.3 With coarse resolution data ............................................... 245 10.3.4 With hyperspectral data..................................................... 247

10.4 Challenges and future directions .................................................. 248 10.4.1 Challenges ......................................................................... 248 10.4.2 Future directions ................................................................ 249

Acknowledgments ................................................................................. 251 References ............................................................................................. 251

index analysis, spectral position variable analysis, transformed feature extraction, spectral mixture analysis, and advanced statistical algorithms for mapping LAI, and two general categories of analysis methods: empirical and statistical methods and physically based modeling. Advantages and disadvantage for specic analysis techniques and approaches are discussed. An overview of estimating and mapping forest LAI with multisatellite sensors and systems, including moderate resolution, high resolution, coarse resolution, and hyperspectral resolution data, is conducted. The challenges and future directions for estimating and mapping forest LAI using various satellite imagery are discussed.