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Recent advances in remote sensing of biophysical variables
Remote Sensing of Environment 79 (2002) 145 – 146 www.elsevier.com/locate/rse
Recent advances in remote sensing of biophysical variables An overview of the special issue The concept for this special issue of Remote Sensing of Environment grew out of a meeting held in the Geography Department of the University of Maryland, College Park, in the Fall of 1998. The papers that follow report on a variety of research activities that have advanced biophysical remote sensing in recent years. The science backgrounds of the authors span a range nearly as broad as the topics they explore, the spatial scales addressed, and the methods and data employed. They make use of a diverse array of remotely sensed imagery, including optical, thermal, radar, and lidar. The common theme is the use of novel techniques and modeling approaches to measure biophysical and land surface properties with remote sensing. These properties are governed by biological and physical processes, vegetation type, amount, distribution, and associated functional attributes. Thus, most of the papers explore some aspect of the biotic controls on land surface processes. The first four papers address optical and thermal remote sensing of land surface and air temperature, comparisons of these to field measurements, independent techniques, and models. A number of issues are raised with respect to the utility of the satellite observational record and the need for corrections to create a consistent time series.
Effects of orbital drift on land surface temperature measured by AVHRR thermal sensors by C. Arthur Gleason, Stephen D. Prince, Scott J. Goetz, and Jennifer Small. The potential of Pathfinder AVHRR data for providing surrogate climate variables across Africa and Europe for epidemiological applications by Robert Green and Simon Hay. Comparison of surface meteorological variables from TOVS and AVHRR by Venkat Lakshmi, Jennifer Small, and Scott J. Goetz. Temperature and emissivity separation from multispectral thermal infrared observations by Thomas Schmugge, Andrew French, Jerry C. Ritchie, Albert Rango, and Henk Pelgrum. The next five papers address optical, thermal, and microwave remote sensing of atmospheric and soil moisture through modeling, fusion of data sets, comparisons with field measurements, and independent methodologies. Four
of the five papers identify the critical need for daily soil moisture estimates over large areas, and assess the limitations of existing techniques utilizing remotely sensed data.
Using covariates to spatially interpolate moisture availability in the Murray-Darling Basin, Southeast Australia: a novel use of remotely sensed data by Tim McVicar and David Jupp. A simple interpretation of the surface temperature/ vegetation index space for assessment of soil moisture status by Inge Sandholt, Kjeld Rasmussen, and Jens Andersen. Evaluating land surface moisture conditions from remotely sensed temperature/vegetation index measurements: an exploration with the simplified simple biosphere model by Samuel N. Goward, Yongkang Xue, and Kevin Czajkowski. Comparison of ERS-2 SAR and Landsat TM imagery for monitoring agricultural crop and soil conditions by M. Susan Moran, Daniel C. Hymer, Jiaguo Qi, and Yann Kerr. Thermal remote sensing of near-surface water vapor by Kevin Czajkowski, Samuel N. Goward, David Shirley, and Anita Walz.
The next four papers use optical, radar and lidar remote sensing to estimate vegetation biophysical properties including leaf area, biomass, and structural characteristics of diverse vegetation types. The techniques employed rely mainly on statistical inference, but lead into methodologies based on inversion of canopy radiative transfer models.
0034-4257/01/$ – see front matter D 2002 Elsevier Science Inc. All rights reserved. PII: S 0 0 3 4 - 4 2 5 7 ( 0 1 ) 0 0 2 6 8 - 1
Satellite mapping of surface biophysical parameters at the biome-scale over the North American grasslands: a case study by Bruce Wylie, David J. Meyer, Larry L. Tiezan, and S. Mannel. Radiometric slope correction for forest biomass estimation from SAR data in the Western Sayani Mountains, Siberia by Guoqing Sun, Jon Ranson, and V. I. Kharuk. Estimating forest structure in wetlands using multitemporal SAR by Philip A. Townshend. Estimation of tropical forest structural characteristics using large-footprint lidar by Jason Drake, Ralph
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S.J. Goetz / Remote Sensing of Environment 79 (2002) 145–146
Dubayah, David B. Clark, Robert G. Knox, J. Bryan Blair, Michelle A. Hofton, Robin L. Chazdon, John F. Weishampel, by Stephen D. Prince. The final three papers use optical and thermal remote sensing to model biophysical variables and related energy terms. Model inversion techniques are used to recover vegetation and land surface dynamics important for macroscale modeling of biospheric processes, including carbon and energy cycles regulated by plant physiology, canopy photosynthesis, and evapotranspiration.
Recovery of forest canopy characteristics through inversion of a complex 3D model by Dan Kimes, J. Gastell-Etchegorry, and P. Este`ve. Evaluating evapotranspiration rates and surface conditions using Landsat TM to estimate atmospheric resistance and surface resistance by Eva Boegh, H. Soegaard, and A. Thomsen. Forward and inverse modeling of land surface energy balance using surface temperature measurements by Mark A. Friedl. This special issue is a response to a need recognized by the authors to give attention to novel techniques that are often underemphasized relative to other types of remote sensing (e.g., image data processing, correction, and classification techniques). These papers provide insight into the many issues that affect the recovery and application of
biophysical and land surface variables. As with all research, they invariably raise as many questions as they answer. At the same time they advance fundamental issues related to improved understanding of the data sets, their research applications, and ultimate utility for investigating biospheric processes.
Acknowledgments I thank the authors who contributed to this special issue and the more than 50 reviewers who dedicated their time and expertise. Marvin Bauer is acknowledged for his assistance with this effort, as well as for his dedication to this excellent journal over the past 20 years. Special thanks also go to Kimberly Pezza and Porsche Klemm for administrative support, Peter Henn and Simon Richert of Elsevier for the assistance with the publication process, and Sam Goward for handling reviews of papers I co-authored. Financial support was provided by Diane Wickland through NASA Grant No. NAG-510126. Scott J. Goetz Department of Geography University of Maryland, College Park MD 20742-8225, USA Tel.: +1-301-405-1297 Fax: +1-301-314-9299 E-mail address: [email protected]
Recent advances in remote sensing of biophysical variables An overview of the special issue The concept for this special issue of Remote Sensing of Environment grew out of a meeting held in the Geography Department of the University of Maryland, College Park, in the Fall of 1998. The papers that follow report on a variety of research activities that have advanced biophysical remote sensing in recent years. The science backgrounds of the authors span a range nearly as broad as the topics they explore, the spatial scales addressed, and the methods and data employed. They make use of a diverse array of remotely sensed imagery, including optical, thermal, radar, and lidar. The common theme is the use of novel techniques and modeling approaches to measure biophysical and land surface properties with remote sensing. These properties are governed by biological and physical processes, vegetation type, amount, distribution, and associated functional attributes. Thus, most of the papers explore some aspect of the biotic controls on land surface processes. The first four papers address optical and thermal remote sensing of land surface and air temperature, comparisons of these to field measurements, independent techniques, and models. A number of issues are raised with respect to the utility of the satellite observational record and the need for corrections to create a consistent time series.
Effects of orbital drift on land surface temperature measured by AVHRR thermal sensors by C. Arthur Gleason, Stephen D. Prince, Scott J. Goetz, and Jennifer Small. The potential of Pathfinder AVHRR data for providing surrogate climate variables across Africa and Europe for epidemiological applications by Robert Green and Simon Hay. Comparison of surface meteorological variables from TOVS and AVHRR by Venkat Lakshmi, Jennifer Small, and Scott J. Goetz. Temperature and emissivity separation from multispectral thermal infrared observations by Thomas Schmugge, Andrew French, Jerry C. Ritchie, Albert Rango, and Henk Pelgrum. The next five papers address optical, thermal, and microwave remote sensing of atmospheric and soil moisture through modeling, fusion of data sets, comparisons with field measurements, and independent methodologies. Four
of the five papers identify the critical need for daily soil moisture estimates over large areas, and assess the limitations of existing techniques utilizing remotely sensed data.
Using covariates to spatially interpolate moisture availability in the Murray-Darling Basin, Southeast Australia: a novel use of remotely sensed data by Tim McVicar and David Jupp. A simple interpretation of the surface temperature/ vegetation index space for assessment of soil moisture status by Inge Sandholt, Kjeld Rasmussen, and Jens Andersen. Evaluating land surface moisture conditions from remotely sensed temperature/vegetation index measurements: an exploration with the simplified simple biosphere model by Samuel N. Goward, Yongkang Xue, and Kevin Czajkowski. Comparison of ERS-2 SAR and Landsat TM imagery for monitoring agricultural crop and soil conditions by M. Susan Moran, Daniel C. Hymer, Jiaguo Qi, and Yann Kerr. Thermal remote sensing of near-surface water vapor by Kevin Czajkowski, Samuel N. Goward, David Shirley, and Anita Walz.
The next four papers use optical, radar and lidar remote sensing to estimate vegetation biophysical properties including leaf area, biomass, and structural characteristics of diverse vegetation types. The techniques employed rely mainly on statistical inference, but lead into methodologies based on inversion of canopy radiative transfer models.
0034-4257/01/$ – see front matter D 2002 Elsevier Science Inc. All rights reserved. PII: S 0 0 3 4 - 4 2 5 7 ( 0 1 ) 0 0 2 6 8 - 1
Satellite mapping of surface biophysical parameters at the biome-scale over the North American grasslands: a case study by Bruce Wylie, David J. Meyer, Larry L. Tiezan, and S. Mannel. Radiometric slope correction for forest biomass estimation from SAR data in the Western Sayani Mountains, Siberia by Guoqing Sun, Jon Ranson, and V. I. Kharuk. Estimating forest structure in wetlands using multitemporal SAR by Philip A. Townshend. Estimation of tropical forest structural characteristics using large-footprint lidar by Jason Drake, Ralph
146
S.J. Goetz / Remote Sensing of Environment 79 (2002) 145–146
Dubayah, David B. Clark, Robert G. Knox, J. Bryan Blair, Michelle A. Hofton, Robin L. Chazdon, John F. Weishampel, by Stephen D. Prince. The final three papers use optical and thermal remote sensing to model biophysical variables and related energy terms. Model inversion techniques are used to recover vegetation and land surface dynamics important for macroscale modeling of biospheric processes, including carbon and energy cycles regulated by plant physiology, canopy photosynthesis, and evapotranspiration.
Recovery of forest canopy characteristics through inversion of a complex 3D model by Dan Kimes, J. Gastell-Etchegorry, and P. Este`ve. Evaluating evapotranspiration rates and surface conditions using Landsat TM to estimate atmospheric resistance and surface resistance by Eva Boegh, H. Soegaard, and A. Thomsen. Forward and inverse modeling of land surface energy balance using surface temperature measurements by Mark A. Friedl. This special issue is a response to a need recognized by the authors to give attention to novel techniques that are often underemphasized relative to other types of remote sensing (e.g., image data processing, correction, and classification techniques). These papers provide insight into the many issues that affect the recovery and application of
biophysical and land surface variables. As with all research, they invariably raise as many questions as they answer. At the same time they advance fundamental issues related to improved understanding of the data sets, their research applications, and ultimate utility for investigating biospheric processes.
Acknowledgments I thank the authors who contributed to this special issue and the more than 50 reviewers who dedicated their time and expertise. Marvin Bauer is acknowledged for his assistance with this effort, as well as for his dedication to this excellent journal over the past 20 years. Special thanks also go to Kimberly Pezza and Porsche Klemm for administrative support, Peter Henn and Simon Richert of Elsevier for the assistance with the publication process, and Sam Goward for handling reviews of papers I co-authored. Financial support was provided by Diane Wickland through NASA Grant No. NAG-510126. Scott J. Goetz Department of Geography University of Maryland, College Park MD 20742-8225, USA Tel.: +1-301-405-1297 Fax: +1-301-314-9299 E-mail address: [email protected]