Article
Agronomy
Jiaqi Guo, Xiaohong Liu, Wensen Ge, Liangju Zhao, Wenjie Fan, Xinyu Zhang, Qiangqiang Lu, Xiaoyu Xing, Zihan Zhou
Summary: Vegetation photosynthetic phenology is an important indicator for understanding the impacts of climate change on terrestrial carbon cycle. This study evaluated and compared the abilities of different spectral indices to model photosynthetic phenology, and found that NIRv and PRI are effective proxies for monitoring photosynthetic phenology.
AGRICULTURAL AND FOREST METEOROLOGY
(2024)
Article
Agriculture, Multidisciplinary
Jae-Hyun RYU, Dohyeok OH, Jaeil CHO
Summary: A spectral reflectance sensor (SRS) was developed to monitor seasonal changes in crops by extracting seasonal signals with a novel filtering method and using sunshine duration to exclude distorted values of vegetation indices. The method improved the seasonal signals of vegetation indices by increasing R2 values on three crops, contributing to agricultural monitoring system by identifying seasonal changes in crop growth and physiological conditions.
JOURNAL OF INTEGRATIVE AGRICULTURE
(2021)
Article
Plant Sciences
Kaori Kohzuma, Maro Tamaki, Kouki Hikosaka
Summary: A method using NPQ(T) to correct PRI for assessing plant responses to drought stress was proposed. Results suggest that PRI is an excellent indicator of environmental stress and recovery in plants, serving as a high-throughput stress detection tool in agriculture.
JOURNAL OF PLANT RESEARCH
(2021)
Article
Plant Sciences
Stephanie C. Schmiege, Kevin L. Griffin, Natalie T. Boelman, Lee A. Vierling, Sarah G. Bruner, Elizabeth Min, Andrew J. Maguire, Johanna Jensen, Jan U. H. Eitel
Summary: Light availability plays a crucial role in vertical canopy gradients. This study found differences in light availability, photosynthetic functioning, and leaf traits between trees at the northern and southern range extremes of white spruce. Unlike many other tree species, high latitude trees may not require vertical gradients to optimize photosynthetic carbon gain. The lower photosynthetic rates and higher respiratory costs could ultimately constrain the northern range limit of this boreal species.
PLANT CELL AND ENVIRONMENT
(2023)
Article
Optics
W. Malek, M. Bouzidi, N. Chaaben, Abdullah S. Alshammari, A. Rebey
Summary: In this study, the decomposition of GaN layers was monitored in situ using a spectral reflectance system, with a particular focus on the early stages of GaN decomposition. The analysis of spectral reflectance behavior revealed a rapid increase in reflectance associated with the formation of a gallium metallic layer. Subsequently, the reflectance showed oscillations and damping with processing time, indicating the decomposition of the GaN layer. The combination of transfer matrix formalism and effective refractive index concept helped to understand the observed reflectance responses during GaN decomposition. An effective refractive index formula that considered the coexistence of gallium and GaN materials was developed to fit the experimental results, which proved to be a useful tool for interpreting the reflectance variations. The results were further validated and analyzed using scanning electron microscopy (SEM) observations and photoluminescence measurements.
Article
Geography, Physical
Alia L. Khan, Heidi M. Dierssen, Ted A. Scambos, Juan Hofer, Raul R. Cordero
Summary: The study on snow algae in the Antarctic Peninsula found that green and red snow algae have significant impact on the albedo and radiative forcing of snow, with green algae having twice the radiative forcing of red algae. The annual snowmelt caused by green snow algae is greater than that caused by red snow algae.
Article
Agriculture, Multidisciplinary
Johann Vollmann, Pablo Rischbeck, Martin Pachner, Vuk Dordevic, Ahmad M. Manschadi
Summary: This study evaluated the use of hyperspectral canopy reflectance measurement as a field-based phenotyping method to indirectly estimate nitrogen fixation and soil nitrogen uptake in soybean genotypes. Prediction models for seed protein content were developed and found to be accurate, especially in environments with lower initial soil mineral N content. Hyperspectral reflectance data proved to be a valuable tool for determining genetic variation in crop N accumulation.
COMPUTERS AND ELECTRONICS IN AGRICULTURE
(2022)
Article
Biochemical Research Methods
Vimal Prabhu Pandiyan, Sierra Schleufer, Emily Slezak, James Fong, Rishi Upadhyay, Austin Roorda, Ren Ng, Ramkumar Sabesan
Summary: This study compared cone classification using optoretinography (ORG) and retinal densitometry. The results showed that ORG has higher sensitivity and dynamic range for detecting cone photopigments, providing greater accuracy in cone spectral classification.
BIOMEDICAL OPTICS EXPRESS
(2022)
Article
Environmental Sciences
Wei Tang, Chengyi Zhao, Jing Lin, Caixia Jiao, Guanghui Zheng, Jianting Zhu, Xishan Pan, Xue Han
Summary: Based on the analysis of the spectral reflection characteristics of muddy coastlines in Jiangsu, an improved spectral water index (IWI) combined with the Otsu algorithm is proposed for coastline extraction. The results show that the proposed method is not affected by tidal conditions or sand content in the water, and it can accurately identify water boundaries and extract muddy coastlines and marine buildings with high accuracy. The method significantly increases the degree of automation and achieves high accuracy in coastline extraction.
Article
Optics
Lixia Wang, Aditya Sole, Jon Yngve Hardeberg, Xiaoxia Wan
Summary: The accuracy of recovered spectra from camera responses depends on the spectral estimation algorithm, camera and filters selected, and the light source used. Comparison of different light source spectrum optimization methods showed that multi-population genetic algorithm (MPGA) has superior performance, providing more accurate spectral reflectance estimation.
Article
Plant Sciences
Anatoly Gitelson, Timothy Arkebauer, Alexei Solovchenko, Anthony Nguy-Robertson, Yoshio Inoue
Summary: Non-invasive comparative analysis was conducted on the spectral composition of energy absorbed by crop species at leaf and plant levels, revealing similar spectral absorption patterns across different crops and confirming the role of green and far-red light in photosynthesis. The use of leaf and plant absorption coefficients shows the potential for quantifying photosynthesis in different spectral ranges.
PHOTOSYNTHESIS RESEARCH
(2022)
Article
Optics
Rong Yan, Shuai Wang, Qiang Jiao, Liheng Bian
Summary: The computational spectrometer can reconstruct spectra based on precalibrated information. It has become an integrated and low-cost paradigm with great potential in portable or handheld spectral analysis devices in the past decade. Different from existing methods, the reported method learns a spectral dictionary via L4-norm maximization, considers statistical ranking of features, and utilizes inverse distance weighting for picking samples and constructing a local training set to achieve high accuracy.
Article
Environmental Sciences
Zbigniew Otremba, Jacek Piskozub
Summary: This study investigated the possibility of detecting oil-in-water emulsions under the sea by modeling the directional distribution of the radiance field above the water surface. By analyzing the optical sea model and the oil emulsion model, the most favorable combination of two wavelengths was identified for determining an index related to polluted sea areas. The study also showed changes in the difference index depending on viewing direction and highlighted the most effective observation directions for detecting emulsions.
Article
Plant Sciences
Praveen Pandey, Swati Singh, Mohammad Saleem Khan, Manoj Semwal
Summary: This study compares non-destructive and destructive methods to measure foliar nitrogen concentration in menthol mint. The results show that the NDRE index calculated from reflectance data can accurately predict the foliar nitrogen concentration.
FRONTIERS IN PLANT SCIENCE
(2022)
Article
Physics, Applied
Bingbing Wang, Yulu Chen, Wulin Tong, Yangzhou Zhou, Jiajia Tao, Zewen Wang, Zuoru Dong, Hong Zhou, Zhanglong Fu, DiXiang Shao, Xiaodong Wang, Juncheng Cao
Summary: This study presents a novel blocked-impurity-band hybrid structure for terahertz radiation detection. The modulation effect of sub-wavelength metal grating on light absorption is analyzed, and the optical absorption and spectral response of the hybrid structure detectors are simulated. The results show selective absorption amplification and filtering effects, as well as significant absorption enhancement at specific wavelengths.
APPLIED PHYSICS LETTERS
(2022)
Article
Geochemistry & Geophysics
Thomas H. G. Vidal, Frederic Jacob, Albert Olioso, Philippe Gamet
Summary: Our study proposes an original approach to optimize the spectral configuration of the Thermal infraRed Imaging Satellite for High-resolution Natural resource Assessment (TRISHNA) instrument for the split-window (SW) method. Results show a significant sensitivity to the positions of TRISHNA SW channels, with favorable positions leading to reduced errors in land surface temperature (LST) retrieval. By considering differences in surface emissivities, an optimal position for one of the channels is identified, with the findings potentially generalizable to other SW formulations.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2022)
Article
Geochemistry & Geophysics
Frederic Jacob, Thomas H. G. Vidal, Audrey Lesaignoux, Albert Olioso, Marie Weiss, Francoise Nerry, Stephane Jacquemoud, Philippe Gamet, Karine Caillault, Luc Labarre, Andrew French, Thomas Schmugge, Xavier Briottet, Jean-Pierre Lagouarde
Summary: In preparation for the MISTIGRI mission, the study investigated the error budget of the TES method with different spectral configurations, highlighting the impact of atmospheric and instrumental noises on the TES retrievals. The study also showed that the TES intrinsic assumption about spectral contrast is a major factor affecting the error budget.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2022)
Article
Agronomy
Samuel Mwangi, Gilles Boulet, Albert Olioso
Summary: The study presents a modified version of the SPARSE model that incorporates sunlit/shaded soil/vegetation elements and a radiative transfer model, improving the retrieval of surface fluxes. It also investigates the sensitivity of flux and component temperature estimates to the viewing direction of the thermal sensor, showing a significant reduction in sensitivity.
AGRICULTURAL AND FOREST METEOROLOGY
(2022)
Article
Geosciences, Multidisciplinary
Anne J. Hoek van Dijke, Martin Herold, Kaniska Mallick, Imme Benedict, Miriam Machwitz, Martin Schlerf, Agnes Pranindita, Jolanda J. E. Theeuwen, Jean-Francois Bastin, Adriaan J. Teuling
Summary: Global tree restoration can have complex and regionally variable impacts on water availability, with tree-cover expansion leading to both increased evaporation and enhanced precipitation. The effects on water availability can vary greatly, with some regions experiencing an increase in water availability while others face a decrease.
Review
Environmental Sciences
Mbali Mahlayeye, Roshanak Darvishzadeh, Andrew Nelson
Summary: Cropping patterns are crucial for crop production and land-use intensity, but they are rarely reported in agricultural statistics. Remote sensing enables mapping of cropping patterns, but research on intercropping patterns is limited and the use of microwave remote sensing for intercropping mapping is not fully explored.
Article
Agronomy
Elmer Kanjo Ekinzog, Martin Schlerf, Martin Kraft, Florian Werner, Angela Riedel, Gilles Rock, Kaniska Mallick
Summary: This study assessed the effectiveness of three CWSI models for crop water stress monitoring in a humid region and found that CWSI accurately estimates soil water content. Among the models, CWSIe and CWSIh performed better than CWSIt and could serve as promising alternatives. Additionally, drone-based CWSI and theta maps captured irrigation patterns well and could assist in irrigation decision-making.
AGRICULTURAL WATER MANAGEMENT
(2022)
Article
Agriculture, Multidisciplinary
Christian Bossung, Martin Schlerf, Miriam Machwitz
Summary: This study analyzed winter wheat samples in France and Belgium to explore the feasibility of using Sentinel-2 satellite data for monitoring canopy nitrogen content (CNC) at high fertilization levels. Three remote sensing methods were compared, and the PROSAIL-LUT method showed better stability and reliability in predicting CNC.
PRECISION AGRICULTURE
(2022)
Article
Environmental Sciences
Nasir Farsad Layegh, Roshanak Darvishzadeh, Andrew K. Skidmore, Claudio Persello, Nina Krueger
Summary: This study aims to develop a classification method by integrating graph-based semi-supervised learning (SSL) and an expert system (ES) to improve the accuracy of vegetation classification. The results show that this method has higher accuracy compared to other classification methods, and using all red-edge spectral band combinations yields the best results.
Review
Environmental Sciences
Katja Berger, Miriam Machwitz, Marlena Kycko, Shawn C. Kefauver, Shari Van Wittenberghe, Max Gerhards, Jochem Verrelst, Clement Atzberger, Christiaan van der Tol, Alexander Damm, Uwe Rascher, Ittai Herrmann, Veronica Sobejano Paz, Sven Fahrner, Roland Pieruschka, Egor Prikaziuk, Ma. Luisa Buchaillot, Andrej Halabuk, Marco Celesti, Gerbrand Koren, Esra Tunc Gormus, Micol Rossini, Michael Foerster, Bastian Siegmann, Asmaa Abdelbaki, Giulia Tagliabue, Tobias Hank, Roshanak Darvishzadeh, Helge Aasen, Monica Garcia, Isabel Pocas, Subhajit Bandopadhyay, Mauro Sulis, Enrico Tomelleri, Offer Rozenstein, Lachezar Filchev, Gheorghe Stancile, Martin Schlerf
Summary: This study provides an overview of the main spectral technologies and retrieval approaches for detecting crop stress in agriculture. Remote sensing technology can capture different plant responses under stress through specific light interaction processes. The analysis of research papers reveals the increasing usage of satellite and unmanned aerial vehicle data and a shift towards more advanced models. However, most studies still focus on proxies calculated from single-source sensor domains, and future research should explore simultaneous analysis of multiple stress responses, integration of multi-domain models and machine learning methods, and assimilation of estimated plant traits into integrated crop growth models.
REMOTE SENSING OF ENVIRONMENT
(2022)
Article
Plant Sciences
Julien Ruffault, Jean-Marc Limousin, Francois Pimont, Jean-Luc Dupuy, Miquel De Caceres, Herve Cochard, Florent Mouillot, Chris J. Blackman, Jose M. Torres-Ruiz, Russell A. Parsons, Myriam Moreno, Sylvain Delzon, Steven Jansen, Albert Olioso, Brendan Choat, Nicolas Martin-StPaul
Summary: Fuel moisture content is a crucial factor for forest fires worldwide, however, its dynamics and determinants in forest canopies remain poorly understood. This study integrated a FMC module into the SurEau-Ecos model to predict leaf live fuel moisture content and canopy fuel moisture content based on leaf water potential. The results showed that drought-induced foliage mortality is expected to increase as the climate gets drier.
Article
Environmental Sciences
Tian Hu, Kaniska Mallick, Glynn C. Hulley, Lluis Perez Planells, Frank M. Gottsche, Martin Schlerf, Patrik Hitzelberger, Yoanne Didry, Zoltan Szantoi, Itziar Alonso, Jose A. Sobrino, Drazen Skokovic, Jean-Louis Roujean, Gilles Boulet, Philippe Gamet, Simon Hook
Summary: This study validates and compares the accuracy of high spatial resolution land surface temperature (LST) products from ECOSTRESS, ASTER, and Landsat, using data from 9 sites in Europe and Africa. The results show consistent performance and high accuracy among these LST products, with some bias and a precision of around 1.5 K. The recalibration of the ECOSTRESS Level 1 radiance data in the future is expected to improve the accuracy of ECOSTRESS LST further.
REMOTE SENSING OF ENVIRONMENT
(2022)
Article
Environmental Sciences
Andrew K. Skidmore, Andjin Siegenthaler, Tiejun Wang, Roshanak Darvishzadeh, Xi Zhu, Anthony Chariton, G. Arjen de Groot
Summary: In this study, the relative abundance of soil microbiome in three terrestrial ecosystems across North America (savanna, boreal, and tundra) was mapped for the first time using airborne image spectroscopy and environmental DNA (eDNA) data. Linear Discriminate Analysis (LDA) scores were used to identify families with the greatest explanatory power in the community composition between the ecosystems. Spatial prediction of relative abundance of different bacteria taxa based on remote sensing was demonstrated, revealing patterns of soil microbiome biodiversity and ecosystem function within and across the three ecosystems.
SCIENCE OF REMOTE SENSING
(2022)
Article
Agronomy
Mario Serouart, Simon Madec, Etienne David, Kaaviya Velumani, Raul Lopez Lozano, Marie Weiss, Frederic Baret
Summary: This study presents a method for pixel segmentation of high-resolution RGB images into vegetation classes. The method achieves accurate segmentation of the images into background, green, and senescent vegetation classes. However, some confusion is observed between the background and senescent vegetation, especially in dark and bright regions. The study also finds that the SVM method provides more precise delineation of the green and senescent patches compared to the convolutional nature of U-net.
Article
Geography
Hunggul Y. S. H. Nugroho, Andrew Skidmore, Yousif A. Hussin
Summary: The decision of the Indonesian constitutional court to review forestry laws in 2013 marked a significant step forward in recognizing the rights of Indigenous people to forest. However, special measures are required to verify Indigenous status. This paper conducted a case study in a protected forest, evaluating the capacity of Indigenous communities to manage the forest and suggesting holistic approaches to ensure sustainable management for the benefit of the community and the environment.