Article
Environmental Sciences
Zhenhua Zhang, Peng Chen, Zhihua Mao
Summary: This study developed an open-source spaceborne oceanic lidar simulator named SOLS and analyzed the maximum detectable depth and optimal wavelength of spaceborne lidar at a global scale. The results show that SOLS can greatly assist in the design of future spaceborne oceanic lidar systems.
Article
Environmental Sciences
Martin Queinnec, Joanne C. White, Nicholas C. Coops
Summary: This study used ICESat-2 data to estimate forest structure in different boreal forest types in Ontario, Canada, including canopy height, cover, and height variability. Results showed strong agreement between ICESat-2 and airborne LiDAR for estimating canopy height in different forest development stages, but ICESat-2 tended to underestimate canopy height variability and cover compared to LiDAR data.
REMOTE SENSING OF ENVIRONMENT
(2021)
Article
Geosciences, Multidisciplinary
Kaori Sato, Hajime Okamoto
Summary: An enhanced understanding of ice-particle microphysics and their formation conditions is necessary for a more accurate representation of ice-phase processes in numerical models. Recent advancements in ice-particle backscattering theories, coupled with space-borne lidar measurements, have enabled a comprehensive exploration of the geographical distribution and seasonal dependence of ice-particle shape categories. This global distribution provides valuable insights into physical processes related to ice cloud particle shape formation, cloud duration, and radiative impacts.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Environmental Sciences
Xiao Ma, Guang Zheng, Xu Chi, Long Yang, Qiang Geng, Jiarui Li, Yifan Qiao
Summary: A generalizable approach to mapping large-scale distributions of building heights using GEDI-derived relative height metrics, optical data, and radar data is proposed. The approach was applied to the Yangtze River Delta region in China, revealing spatial distribution patterns of building heights and the effect of urbanization on mean building heights.
REMOTE SENSING OF ENVIRONMENT
(2023)
Article
Optics
Mengyang Cai, Ge Han, Xin Ma, Zhipeng Pei, Wei Gong
Summary: A novel active-passive collaborative retrieval method for measuring XCO2 (APCRM-CO2) is proposed, which combines observations from spectrometers and IPDA LIDAR to achieve high information content and coverage advantages. Simulation experiments show that this method can significantly reduce retrieval errors and has great potential for performance improvements in future real data processing.
Article
Environmental Sciences
Alexander K. Killion, Arata Honda, Edward Trout, Neil H. Carter
Summary: Vegetation structure is important for wildlife habitat and can be measured using NASA's GEDI data. In this study, GEDI data was used to estimate habitat use in a remote mountain system in central Idaho, USA. Structural diversity indices of canopy height, foliage height diversity, and plant area index had the strongest effects on mammal occupancy compared to 2D variables.
ENVIRONMENTAL RESEARCH LETTERS
(2023)
Article
Forestry
Li Xu, Qingtai Shu, Huyan Fu, Wenwu Zhou, Shaolong Luo, Yingqun Gao, Jinge Yu, Chaosheng Guo, Zhengdao Yang, Jinnan Xiao, Shuwei Wang
Summary: This study used GEDI data and Kriging interpolation to establish biomass models for Quercus forests. The results showed that the random forest model had higher accuracy compared to multiple linear regression and support vector regression. This study provides a new research direction for estimating other forest structural parameters using GEDI data.
Article
Thermodynamics
Tianqi Shi, Ge Han, Xin Ma, Zhipeng Pei, Weibo Chen, Jiqiao Liu, Xingying Zhang, Siwei Li, Wei Gong
Summary: Accurate reporting of CO2 point source emissions is crucial for addressing climate change. Satellite remote sensing, specifically spaceborne LiDAR, has shown promise as a cost-effective global-scale verification method. A novel emission inversion method using genetic algorithms and trust-region techniques was proposed to estimate CO2 emissions from point sources using spaceborne LiDAR observations. The results demonstrate that this approach provides affordable and accurate carbon verification services.
ENERGY CONVERSION AND MANAGEMENT
(2023)
Article
Environmental Sciences
Xuanye Zhang, Miaomiao Zhang, Lingbing Bu, Zengchang Fan, Ahmad Mubarak
Summary: Methane (CH4) is the second most important greenhouse gas, and accurately monitoring its global concentration is crucial for studying carbon cycle and global warming. The spaceborne integrated path differential absorption (IPDA) lidar, optimized through wavelength, is an effective tool for methane detection. We investigated the relationship between the IPDA lidar system, based on wavelength optimization, and the measurement error of CH4 column-averaged concentration. By selecting the wavelengths with the lowest comprehensive error, we reduced the error by approximately 10 ppb. Our study provides a simulation model for globally simulating methane concentration under real atmospheric conditions, and we ensured that the maximum inversion error for CH4 measurement is less than 10 ppb after optimizing the lidar system parameters, which can guide the design of spaceborne IPDA lidar systems for high-precision CH4 column-averaged concentration detection.
Article
Environmental Sciences
Vincent Casse, Raymond Armante, Philippe Bousquet, Olivier Chomette, Cyril Crevoisier, Thibault Delahaye, Dimitri Edouart, Fabien Gibert, Bruno Millet, Frederic Nahan, Clemence Pierangelo
Summary: This paper introduces two software programs developed in the context of the French-German spatial lidar mission MERLIN: LIDSIM and PROLID, aiming to evaluate the instrument design performance and study the sensitivity of this performance to geophysical parameters. Results show that Merlin target performance may not be reachable, but breakthrough performance has been achieved.
Article
Environmental Sciences
Farid Atmani, Bodo Bookhagen, Taylor Smith
Summary: This study presents a novel Sparse Vegetation Detection Algorithm (SVDA) using ICESat-2 data to map tree and vegetation heights in a sparsely vegetated savanna ecosystem. The algorithm effectively identifies canopy photons and provides the first estimates of seasonal biomass changes.
Article
Remote Sensing
Xuerui Wu, Fang Wang
Summary: In the past three decades, GNSS-R has been widely used as a remote sensing technique, and several spaceborne missions have been launched for its development. The application of GNSS-R to vegetation monitoring has gained attention due to its lack of saturation effect compared to traditional radar. We propose a full polarization GNSS-R vegetation simulator, LAGRS-Veg, which integrates the vegetation radiative transfer equation model and GNSS scattering model. This simulator provides a comprehensive tool for studying spaceborne GNSS-R and analyzing the impact of various vegetation parameters.
Article
Environmental Sciences
Johannes N. Hansen, Steven Hancock, Ludwig Prade, Gerald M. Bonner, Haochang Chen, Ian Davenport, Brynmor E. Jones, Matthew Purslow
Summary: This paper investigates the potential for using diode lasers as an alternative to solid-state lasers in satellite lidar applications. The authors assess whether the novel lidar modalities necessitated by lower peak powers of diode lasers can match the design performance of existing instruments. The results show that diode lasers have the opportunity to be used in spaceborne lidars, potentially allowing wider coverage through their higher efficiencies.
Article
Ecology
Lisa Mandl, Ana Stritih, Rupert Seidl, Christian Ginzler, Cornelius Senf
Summary: The launch of NASA's GEDI mission in 2018 provides new opportunities for describing forest ecosystems across large scales. The study quantified GEDI's potential to estimate forest structure in mountain landscapes and found a high agreement between GEDI and ALS at the landscape level. The research highlights the importance of GEDI for ecosystem dynamics and management.
REMOTE SENSING IN ECOLOGY AND CONSERVATION
(2023)
Article
Environmental Sciences
Ben Spracklen, Dominick V. Spracklen
Summary: The study used LiDAR data from NASA's GEDI project to analyze the structure of old-growth forests in the Ukrainian Carpathian Mountains, finding significant differences in structural metrics between old-growth forests and non-old-growth forests, with OGF being more open, having a more complex vertical structure, and thicker ground-layer vegetation.
Article
Environmental Sciences
Xiaoqiang Liu, Yanjun Su, Tianyu Hu, Qiuli Yang, Bingbing Liu, Yufei Deng, Hao Tang, Zhiyao Tang, Jingyun Fang, Qinghua Guo
Summary: This study developed a novel neural network guided interpolation (NNGI) method to map forest canopy height using integrated spaceborne lidar data and optical images. The results showed high mapping accuracy, demonstrating the feasibility of the proposed method for monitoring forest canopy height at national to global scales and advancing our understanding of forest ecosystem processes and carbon storage.
REMOTE SENSING OF ENVIRONMENT
(2022)
Article
Environmental Sciences
Amy Neuenschwander, Lori Magruder, Eric Guenther, Steven Hancock, Matt Purslow
Summary: This paper investigates the elevation measurements of the ICESat-2 satellite, focusing on the impact of atmospheric scattering and attenuation on radiometry and the differences in radiometry between day and night. The research finds that the radiometry characteristics of the ATLAS instrument vary among different forest types, with higher radiometry observed for weak beams. Additionally, the study observes lower radiometry for daytime acquisitions compared to nighttime acquisitions.
Article
Environmental Sciences
Laura Duncanson, James R. Kellner, John Armston, Ralph Dubayah, David M. Minor, Steven Hancock, Sean P. Healey, Paul L. Patterson, Svetlana Saarela, Suzanne Marselis, Carlos E. Silva, Jamis Bruening, Scott J. Goetz, Hao Tang, Michelle Hofton, Bryan Blair, Scott Luthcke, Lola Fatoyinbo, Katharine Abernethy, Alfonso Alonso, Hans-Erik Andersen, Paul Aplin, Timothy R. Baker, Nicolas Barbier, Jean Francois Bastin, Peter Biber, Pascal Boeckx, Jan Bogaert, Luigi Boschetti, Peter Brehm Boucher, Doreen S. Boyd, David F. R. P. Burslem, Sofia Calvo-Rodriguez, Jerome Chave, Robin L. Chazdon, David B. Clark, Deborah A. Clark, Warren B. Cohen, David A. Coomes, Piermaria Corona, K. C. Cushman, Mark E. J. Cutler, James W. Dalling, Michele Dalponte, Jonathan Dash, Sergio de-Miguel, Songqiu Deng, Peter Woods Ellis, Barend Erasmus, Patrick A. Fekety, Alfredo Fernandez-Landa, Antonio Ferraz, Rico Fischer, Adrian G. Fisher, Antonio Garcia-Abril, Terje Gobakken, Jorg M. Hacker, Marco Heurich, Ross A. Hill, Chris Hopkinson, Huabing Huang, Stephen P. Hubbell, Andrew T. Hudak, Andreas Huth, Benedikt Imbach, Kathryn J. Jeffery, Masato Katoh, Elizabeth Kearsley, David Kenfack, Natascha Kljun, Nikolai Knapp, Kamil Kral, Martin Krucek, Nicolas Labriere, Simon L. Lewis, Marcos Longo, Richard M. Lucas, Russell Main, Jose A. Manzanera, Rodolfo Vasquez Martinez, Renaud Mathieu, Herve Memiaghe, Victoria Meyer, Abel Monteagudo Mendoza, Alessandra Monerris, Paul Montesano, Felix Morsdorf, Erik Naesset, Laven Naidoo, Reuben Nilus, Michael O'Brien, David A. Orwig, Konstantinos Papathanassiou, Geoffrey Parker, Christopher Philipson, Oliver L. Phillips, Jan Pisek, John R. Poulsen, Hans Pretzsch, Christoph Rudiger, Sassan Saatchi, Arturo Sanchez-Azofeifa, Nuria Sanchez-Lopez, Robert Scholes, Carlos A. Silva, Marc Simard, Andrew Skidmore, Krzysztof Sterenczak, Mihai Tanase, Chiara Torresan, Ruben Valbuena, Hans Verbeeck, Tomas Vrska, Konrad Wessels, Joanne C. White, Lee J. T. White, Eliakimu Zahabu, Carlo Zgraggen
Summary: This paper presents the development of models used by NASA's Global Ecosystem Dynamics Investigation (GEDI) to estimate forest aboveground biomass density (AGBD). The models were developed using globally distributed field and airborne lidar data, with simulated relative height metrics as predictor variables. The study found that stratification by geographic domain and the use of square root transformation improved model performance.
REMOTE SENSING OF ENVIRONMENT
(2022)
Article
Environmental Sciences
Johannes N. Hansen, Steven Hancock, Ludwig Prade, Gerald M. Bonner, Haochang Chen, Ian Davenport, Brynmor E. Jones, Matthew Purslow
Summary: This paper investigates the potential for using diode lasers as an alternative to solid-state lasers in satellite lidar applications. The authors assess whether the novel lidar modalities necessitated by lower peak powers of diode lasers can match the design performance of existing instruments. The results show that diode lasers have the opportunity to be used in spaceborne lidars, potentially allowing wider coverage through their higher efficiencies.
Letter
Ecology
Christopher R. Hakkenberg, Hao Tang, Patrick Burns, Scott J. Goetz
FRONTIERS IN ECOLOGY AND THE ENVIRONMENT
(2023)
Article
Environmental Sciences
K. C. Cushman, John Armston, Ralph Dubayah, Laura Duncanson, Steven Hancock, David Janik, Kamil Kral, Martin Krucek, David M. Minor, Hao Tang, James R. Kellner
Summary: In this study, the sensitivity of Global Ecosystem Dynamics Investigation (GEDI) data and aboveground biomass density (AGBD) predictions to leaf phenology was tested. The results suggest that, with consideration of model choice, GEDI data without considering leaf status can be used for AGBD prediction, which increases data availability and reduces sampling error in some forests.
ENVIRONMENTAL RESEARCH LETTERS
(2023)
Article
Geography, Physical
Qiuli Yang, Chunyue Niu, Xiaoqiang Liu, Yuhao Feng, Qin Ma, Xuejing Wang, Hao Tang, Qinghua Guo
Summary: This study used multiple remote sensing data and ground-truth measurements to train a random forest regression model for estimating forest aboveground biomass (AGB) in China at a 30-meter resolution. The accuracy of the estimated AGB was R-2 = 0.67 and RMSE = 70.71 Mg/ha. The high-resolution AGB map provides alternative data for carbon cycle studies and serves as a baseline map for forest management and conservation practices.
GISCIENCE & REMOTE SENSING
(2023)
Article
Biodiversity Conservation
Lei Ma, George Hurtt, Hao Tang, Rachel Lamb, Andrew Lister, Louise Chini, Ralph Dubayah, John Armston, Elliott Campbell, Laura Duncanson, Sean Healey, Jarlath O'Neil-Dunne, Lesley Ott, Benjamin Poulter, Quan Shen
Summary: Forest carbon is a significant and uncertain part of the global carbon cycle. Advances in remote sensing and ecosystem modelling, using data collected by NASA lidar missions, have provided better insights into forest structure and its impact on carbon stocks and fluxes. This study demonstrates the potential of spaceborne lidar observations for improving global carbon modelling.
GLOBAL CHANGE BIOLOGY
(2023)
Correction
Environmental Sciences
Hao Tang, Jason Stoker, Scott Luthcke, John Armston, Kyungtae Lee, Bryan Blair, Michelle Hofton
REMOTE SENSING OF ENVIRONMENT
(2023)
Article
Environmental Sciences
Hao Tang, Jason Stoker, Scott Luthcke, John Armston, Kyungtae Lee, Bryan Blair, Michelle Hofton
Summary: NASA's GEDI mission aims to provide high-resolution measurements of forest structure and topography, but current geolocation accuracy limits its applications. Researchers developed a method using lidar data to evaluate and mitigate geolocation errors, finding large errors in the first release of GEDI data but improved accuracy in the second release. This approach provides a short-term solution for improved calibration and validation of GEDI and has the potential to generate biomass products using in-situ data.
REMOTE SENSING OF ENVIRONMENT
(2023)
Article
Geography, Physical
Zehua Huang, Liheng Zhong, Feng Zhao, Jin Wu, Hao Tang, Zhengang Lv, Binyuan Xu, Longfei Zhou, Rui Sun, Ran Meng
Summary: Plantation forests have expanded worldwide and accurate mapping of tree species is crucial for their management. A deep learning-based method was developed to automatically extract spectral-temporal features from satellite image time series, improving the accuracy of tree species mapping.
ISPRS JOURNAL OF PHOTOGRAMMETRY AND REMOTE SENSING
(2023)
Article
Environmental Sciences
Alexander R. Cobb, Rene Dommain, Rahayu S. Sukri, Faizah Metali, Bodo Bookhagen, Charles F. Harvey, Hao Tang
Summary: Tropical peatlands hold significant carbon stocks in the form of peat, with peat domes being the main carbon storage structure. Measuring the subtle topographic relief of these peat domes is challenging, but spaceborne laser altimetry data from satellites like GEDI and ATLAS could provide valuable insights. The study evaluated the accuracy of these data in comparison to airborne lidar data, and found that with spatial filtering, the spaceborne platforms can provide useful altimetry data for tropical peatlands.
SCIENCE OF REMOTE SENSING
(2023)
Article
Engineering, Electrical & Electronic
Changhyun Choi, Victor Cazcarra-Bes, Roman Guliaev, Matteo Pardini, Konstantinos P. P. Papathanassiou, Wenlu Qi, John Armston, Ralph O. O. Dubayah
Summary: The present study focuses on developing, implementing, and validating a forest height mapping scheme by combining TanDEM-X interferometric coherence and GEDI waveform measurements. The study assumes the availability of only a single polarisation TanDEM-X interferogram, a set of spatially discrete GEDI waveform measurements, and no DTM. The study aims to develop a methodology for inverting forest height at large scales, achieving a spatially continuous 25-m resolution forest height map covering the whole of Tasmania Island by combining 595 TanDEM-X scenes and about 15 million GEDI waveforms. The derived forest height map is validated against an airborne lidar-derived canopy height map available across the whole island.
IEEE JOURNAL OF SELECTED TOPICS IN APPLIED EARTH OBSERVATIONS AND REMOTE SENSING
(2023)
Article
Geosciences, Multidisciplinary
Lei Ma, George Hurtt, Lesley Ott, Ritvik Sahajpal, Justin Fisk, Rachel Lamb, Hao Tang, Steve Flanagan, Louise Chini, Abhishek Chatterjee, Joseph Sullivan
Summary: Researchers have conducted a global evaluation of the Ecosystem Demography model (ED v3.0) and made significant advances in accurately predicting the future dynamics of terrestrial ecosystems. The model incorporates underlying mechanistic ecological processes and can simulate vegetation dynamics from local to global scales. It also includes submodules for soil biogeochemistry and soil hydrology.
GEOSCIENTIFIC MODEL DEVELOPMENT
(2022)
