Article
Ecology
Qiaoli Wu, Shenhui Yang, Jie Jiang
Summary: The product of leaf area index (LAI) and clumping index (CI) quantifies the effective leaf abundance and distribution across the landscape. This study simulated how canopy bidirectional reflectance distribution function (BRDF) responds to changes in CI in Qinghai spruce forests and found that the red band BRF showed higher sensitivity to changes in CI than the near-infrared (NIR) band.
FRONTIERS IN FORESTS AND GLOBAL CHANGE
(2023)
Article
Environmental Sciences
Peiqi Yang, Wout Verhoef, Egor Prikaziuk, Christiaan van der Tol
Summary: The study demonstrates the use of temporal autocorrelation to improve the accuracy of remote sensing retrieval of vegetation properties, particularly leaf area index. The method shows promising results in estimating land surface biophysical variables and reduces unrealistic short-term fluctuations in the retrieved data, showing potential for application in various land cover types and improving upon existing products such as MODIS LAI.
REMOTE SENSING OF ENVIRONMENT
(2021)
Article
Environmental Sciences
Hu Zhang, Jing Li, Qinhuo Liu, Yadong Dong, Songze Li, Zhaoxing Zhang, Xinran Zhu, Liangyun Liu, Jing Zhao
Summary: The paper proposes a method to estimate LAI using the actual leaf optical property of pixels, calculated from the leaf chlorophyll content product, with a 3D-RTM-based look-up table method. By utilizing dynamic SSA based on the Chl(leaf) product, the inversion algorithm shows improvement in retrieval index and RMSE in simulations, reducing overestimation problems under high LAI conditions.
Article
Remote Sensing
Jie Zhang, Jinyan Tian, Xiaojuan Li, Le Wang, Beibei Chen, Huili Gong, Rongguang Ni, Bingfeng Zhou, Cankun Yang
Summary: This study is the first to use photon counting LiDAR to inverse leaf area index (LAI), showing the feasibility and accuracy of this method. The results demonstrate satisfactory agreements between ICESat-2 derived LAI and MODIS/Sentinel-2 derived LAI, indicating the reliability of ICESat-2 and its advantages over MODIS in terms of LAI estimation.
INTERNATIONAL JOURNAL OF APPLIED EARTH OBSERVATION AND GEOINFORMATION
(2021)
Article
Remote Sensing
Achraf Makhloufi, Abdelaziz Kallel, Rayda Chaker, Jean-Philippe Gastellu-Etchegorry
Summary: This study aims to estimate and monitor the biophysical properties of olive trees in super-intensive groves using innovative forward/backward radiative transfer modeling. The model utilizes the DART model to simulate realistic olive tree mock-ups with high accuracy and neural networks for property estimation. The dataset covers various biophysical and structural properties of olive trees to ensure accurate retrieval and validation is done using in-situ measurements.
INTERNATIONAL JOURNAL OF REMOTE SENSING
(2021)
Article
Agronomy
Taifeng Dong, Jane Liu, Jiangui Liu, Liming He, Rong Wang, Budong Qian, Heather McNairn, Jarrett Powers, Yichao Shi, Jing M. Chen, Jiali Shang
Summary: In this study, the consistency of crop LAI derived from Sentinel-2 and Landsat 8 satellite data using two retrieval approaches was assessed. The results showed that the hybrid approach achieved good spatiotemporal consistencies in LAI estimates from the two satellites.
AGRICULTURAL AND FOREST METEOROLOGY
(2023)
Article
Environmental Sciences
Bitam Ali, Feng Zhao, Zhenjiang Li, Qichao Zhao, Jiabei Gong, Lin Wang, Peng Tong, Yanhong Jiang, Wei Su, Yunfei Bao, Juan Li
Summary: The maturity and affordability of LiDAR sensors enable quick acquisition of 3D point cloud data for monitoring vegetation canopy traits, but there are few studies on reconstructing 3D structures and extracting fine-scale parameters from terrestrial LiDAR data, posing challenges in requiring large datasets for representation of canopy components.
Article
Geosciences, Multidisciplinary
Stella Bourdin, Lukas Kluft, Bjorn Stevens
Summary: The study shows that climate sensitivity depends on the vertical distribution of humidity, with higher humidity leading to a higher temperature increase. Differences in the vertical distribution of relative humidity explain differences in climate sensitivity among models. Recent trends in humidity suggest Earth is becoming more sensitive to forcing over time.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Environmental Sciences
Yanqun Pan, Simon Belanger, Yannick Huot
Summary: Atmospheric correction of satellite optical imagery over inland waters is a challenging task in aquatic remote sensing. The tested algorithms did not meet the retrieval accuracy target due to uncorrected adjacency effects.
Article
Environmental Sciences
Si Gao, Run Zhong, Kai Yan, Xuanlong Ma, Xinkun Chen, Jiabin Pu, Sicong Gao, Jianbo Qi, Gaofei Yin, Ranga B. Myneni
Summary: Vegetation indices (VIs) are widely used for remote sensing monitoring of vegetation vigor and growth dynamics. However, the saturation phenomenon of VIs limits their ability to characterize surface vegetation over dense canopies. In this study, two indicators were proposed to describe the saturation phenomenon, and the performance of different VIs under various conditions was evaluated using simulation and satellite data. The results showed that the simple ratio vegetation index (SR) performed best, with the highest saturation point and good characterization of surface vegetation until LAI reaches 4.
REMOTE SENSING OF ENVIRONMENT
(2023)
Article
Environmental Sciences
Federico Santini, Angelo Palombo
Summary: This paper investigates the impact of topographic correction on remote sensing images and highlights the necessity of atmospheric correction in mountainous environments. By using data acquired under different illumination conditions with different sensors and conducting a statistical analysis, the importance of topographic correction is demonstrated.
Article
Computer Science, Interdisciplinary Applications
Helene Bloch, Pascal Tremblin, Matthias Gonzalez, Edouard Audit
Summary: We present a geometric multigrid solver for the M-1 model of radiative transfer without source terms, and propose a method to preserve the admissible states by introducing a pseudo-time. Preliminary results show that increasing the number of multigrid levels can decrease the number of iterations and computational cost, indicating that nonlinear multigrid methods can be used as a robust implicit solver for hyperbolic systems like the M1 model.
JOURNAL OF COMPUTATIONAL PHYSICS
(2022)
Article
Geochemistry & Geophysics
Vijay Pratap Yadav, Rajendra Prasad, Ruchi Bala, Prashant K. Srivastava
Summary: This study attempted to use a synergetic approach of modified water cloud model (MWCM) and modified soil scattering model (MSSM) to retrieve the leaf area index (LAI) of wheat and barley crops, with the goal of minimizing errors in biophysical parameters' retrieval. Statistical analysis showed that this approach is capable of accurately obtaining LAI values.
IEEE GEOSCIENCE AND REMOTE SENSING LETTERS
(2022)
Article
Geosciences, Multidisciplinary
Sebastien Massart, Niels Bormann, Massimo Bonavita, Cristina Lupu
Summary: This study presents two approaches to integrate skin temperature into the control variable for optimizing clear-sky radiances. Results show a neutral impact of both approaches on analysis and forecast, and suggest the need to better represent the contribution of subsurface layers for skin temperature associated with microwave instruments.
GEOSCIENTIFIC MODEL DEVELOPMENT
(2021)
Article
Optics
Biao Wang
Summary: The Hemispherical Harmonic Method (HSHM) is a new approach for radiative transfer in plane-parallel atmospheres, with a prototype model showing accuracy and efficiency compared to the Discrete Ordinate Method (DOM). The HSHM model allows for more flexible settings and is inherently immune to singularity problems at certain solar zenith angles, providing another option for modeling and remote sensing studies involving radiance and irradiance in planetary atmospheres.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2021)
