Review
Environmental Sciences
Hongliang Fang
Summary: This review summarizes the current developments of the photon recollision probability and spectral invariant theory in the vegetation remote sensing community, discusses future research directions, aiming to enhance our understanding of this theory and its applications.
REMOTE SENSING OF ENVIRONMENT
(2023)
Article
Geography, Physical
Terhikki Manninen, Kati Anttila, Emmihenna Jaaskelainen, Aku Riihela, Jouni Peltoniemi, Petri Raisanen, Panu Lahtinen, Niilo Siljamo, Laura Tholix, Outi Meinander, Anna Kontu, Hanne Suokanerva, Roberta Pirazzini, Juha Suomalainen, Teemu Hakala, Sanna Kaasalainen, Harri Kaartinen, Antero Kukko, Olivier Hautecoeur, Jean-Louis Roujean
Summary: This study presents a snow surface albedo model considering small-scale surface roughness effects, based on photon recollision probability, which can be combined with existing bulk volume albedo models. The research shows that surface roughness has a greater impact on albedo as the melting season progresses, and it increases backward scattering, particularly for larger solar zenith angle values.
Article
Environmental Sciences
Hans Henniger, Friedrich J. Bohn, Kim Schmidt, Andreas Huth
Summary: To understand the dynamics of forests in today's changing environmental conditions, it is crucial to analyze their state at large scales. Forest inventories are not available for all regions, so additional methods such as remote sensing observations are important. This study combines the radiative transfer model mScope and the forest model FORMIND to generate reflectance spectra for forests, allowing for the consideration of species diversity at different heights. The results show good correlations between the generated reflectances and measured values, opening up possibilities for analyzing forest reflectance and understanding forest conditions.
Article
Agronomy
Petri R. Forsstrom, Jussi Juola, Miina Rautiainen
Summary: This study analyzed the spectral reflectance factors and fractional covers of understory vegetation in different forest stands in a southern boreal forest area in Finland. The results showed specific spectral features of the understory related to site fertility type and fractional cover. The findings suggest that remote sensing can differentiate forest site fertility types and estimate understory green fractional cover in northern European boreal forests.
AGRICULTURAL AND FOREST METEOROLOGY
(2021)
Article
Environmental Sciences
Aarne Hovi, Daniel Schraik, Jan Hanus, Lucie Homolova, Jussi Juola, Mait Lang, Petr Lukes, Jan Pisek, Miina Rautiainen
Summary: This article reports a new version and empirical evaluation of a forest reflectance model based on photon recollision probability. The study shows that this model can accurately estimate the reflectance spectra of forests when considering the various structure and spectral characteristics of the canopy. The previous models that only consider leaves or needles as plant elements and assume a Lambertian canopy tend to overestimate the reflectance, especially in the near-infrared region.
REMOTE SENSING OF ENVIRONMENT
(2022)
Article
Environmental Sciences
Xuezheng Zong, Xiaorui Tian, Xianli Wang
Summary: The study found that an optimal firebreak design can effectively reduce burn probability, especially in high-burn probability areas.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Engineering, Environmental
Emmihenna Jaaskelainen, Terhikki Manninen
Summary: Seasonal snow cover significantly affects the albedo values of boreal forests, increasing forest albedo and altering diurnal variations. Considering the effects of forest floor and multiple scattering is crucial to accurately estimate forest albedo values and reflected solar energy, as neglecting them can lead to significant underestimations.
COLD REGIONS SCIENCE AND TECHNOLOGY
(2021)
Article
Environmental Sciences
John Salisbury, Xiangping Hu, James D. M. Speed, Cristina Maria Iordan, Gunnar Austrheim, Francesco Cherubini
Summary: Moose browsing selectively affects aboveground tree biomass and albedo, with higher biomass in unbrowsed plots and increased cooling effects from increased albedo. The impact of moose browsing on forest structure is stronger than its impact on composition. In regions with intensive forestry operations and high moose density, CO2 emissions from moose browsing can be significant, but the cooling effects from increased albedo can partially offset this impact.
JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
(2023)
Article
Meteorology & Atmospheric Sciences
Terhikki Manninen, Jean-Louis Roujean, Olivier Hautecoeur, Aku Riihela, Panu Lahtinen, Emmihenna Jaaskelainen, Niilo Siljamo, Kati Anttila, Timo Sukuvaara, Lauri Korhonen
Summary: The study found that the relationship between surface albedo and effective leaf area index is independent of flight altitude, with a 20 km footprint being representative of the landscape, and albedo showing sensitivity to sparse vegetation.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2022)
Article
Ecology
Jussi Juola, Aarne Hovi, Miina Rautiainen
Summary: The woody material of forest canopies affects the interpretation of remotely sensed data. This study developed a novel measurement setup and used a mobile hyperspectral camera to measure the stem bark reflectance spectra of ten tree species. The results showed that there was similarity in the visible region, but large interspecific variation in the near-infrared region.
ECOLOGY AND EVOLUTION
(2022)
Article
Environmental Sciences
Bibhash Nath, Wenge Ni-Meister
Summary: Forests are crucial for maintaining the Earth's energy balance, but their variability in canopy structure, topography, and vegetation background conditions can create uncertainties in modeling solar radiation. This study in a boreal region of Alaska analyzed seasonal variation in reflectance with respect to land cover classes, canopy structures, and topography, finding complex interactions between canopy structure and topography, especially during the snow season. The study also highlighted the significant influence of tree height, canopy cover, and rugosity on surface reflectance in different vegetation types.
Article
Environmental Sciences
Anxin Ding, Han Ma, Shunlin Liang, Tao He
Summary: The study developed a tangible parametric model of soil hyperspectral bidirectional reflectance by evaluating and extending the Hapke model. The Hapke-HSR model effectively captured the characteristics of soil hyperspectral reflectance and showed high prediction accuracy.
REMOTE SENSING OF ENVIRONMENT
(2022)
Article
Environmental Sciences
Tongxin Wang, Hongyan Zhang, Jianjun Zhao, Xiaoyi Guo, Tao Xiong, Rihan Wu
Summary: Global evapotranspiration has been increasing in recent decades with global warming, particularly in boreal forest areas, where it is mainly influenced by atmospheric demand and humidity constraints.
Article
Chemistry, Analytical
Sara Mosca, Priyanka Dey, Marzieh Salimi, Benjamin Gardner, Francesca Palombo, Nick Stone, Pavel Matousek
Summary: The proposed method utilizes Spatially Offset Raman Spectroscopy (SORS) to estimate the reduced scattering coefficient (mu(s)') of turbid samples, with high accuracy achieved through calibration on a PTFE model sample. Knowledge of mu(s)' in the NIR range is valuable for optimizing SORS illumination and geometric configurations, providing in-depth information about SORS measurements, and benefiting various photon applications in fields such as biomedical, pharmaceutical, security, forensic, and cultural sciences.
ANALYTICAL CHEMISTRY
(2021)
Article
Chemistry, Analytical
Sara Mosca, Priyanka Dey, Marzieh Salimi, Benjamin Gardner, Francesca Palombo, Nick Stone, Pavel Matousek
Summary: This study investigates how SORS probes for specific depths in turbid samples, highlighting the reduced scattering coefficient of the medium as a key parameter in determining the probed zone. The proposed methodology was tested with experimental data, showing its relevance to a wide range of SORS applications and the importance of providing additional information for SORS measurements.
ANALYTICAL CHEMISTRY
(2021)
Article
Agronomy
Daniel Schraik, Aarne Hovi, Miina Rautiainen
Summary: The clumping of coniferous needles into shoots is a recognized structural feature in radiation regime models, but higher level clumping is often overlooked. Clumping reduces light interception and increases light penetration depth. The authors propose a new method to quantify clumping at different levels using laser scanning data.
AGRICULTURAL AND FOREST METEOROLOGY
(2021)
Article
Environmental Sciences
Titta Majasalmi, Miina Rautiainen
Summary: Forest extent mapping is crucial for climate modeling and ecosystem monitoring. Different global land cover products use simple tree cover definitions to differentiate forests from non-forests. This study assessed tree cover representations of three global LC products in 2017, showing that tree cover accuracy varied between 42 and 75%, with large differences in spatial distributions of coniferous and deciduous species. The CCI LC product demonstrated the best spatial mapping of coniferous and deciduous tree covers compared to reference data from MS-NFI.
ENVIRONMENTAL MONITORING AND ASSESSMENT
(2021)
Article
Environmental Sciences
Petri R. Forsstrom, Aarne Hovi, Giulia Ghielmetti, Michael E. Schaepman, Miina Rautiainen
Summary: Understanding the reflectance anisotropy of forests and the underlying scattering mechanisms is crucial for improving the accuracy of extracting fundamental forest characteristics from optical remote sensing data. This study developed a laboratory setup to measure multiangular spectra of three common European tree species and found that the anisotropy of trees is strongly asymmetrical and characteristic to species. The simultaneous measurements of spectral and directional characteristics of trees may enhance the discrimination of species and support the retrieval of their biophysical properties.
REMOTE SENSING OF ENVIRONMENT
(2021)
Article
Environmental Sciences
Aarne Hovi, Daniel Schraik, Jan Hanus, Lucie Homolova, Jussi Juola, Mait Lang, Petr Lukes, Jan Pisek, Miina Rautiainen
Summary: This article reports a new version and empirical evaluation of a forest reflectance model based on photon recollision probability. The study shows that this model can accurately estimate the reflectance spectra of forests when considering the various structure and spectral characteristics of the canopy. The previous models that only consider leaves or needles as plant elements and assume a Lambertian canopy tend to overestimate the reflectance, especially in the near-infrared region.
REMOTE SENSING OF ENVIRONMENT
(2022)
Article
Forestry
Titta Majasalmi, Miina Rautiainen
Summary: A new approach was developed to calibrate phenological events in boreal forests using satellite and surface temperature data. Results showed that using standard phenometrics directly on satellite data may lead to biases in all species groups.
ANNALS OF FOREST SCIENCE
(2022)
Article
Ecology
Jussi Juola, Aarne Hovi, Miina Rautiainen
Summary: The woody material of forest canopies affects the interpretation of remotely sensed data. This study developed a novel measurement setup and used a mobile hyperspectral camera to measure the stem bark reflectance spectra of ten tree species. The results showed that there was similarity in the visible region, but large interspecific variation in the near-infrared region.
ECOLOGY AND EVOLUTION
(2022)
Article
Environmental Sciences
Pavel Samec, Romana Kudelkova, Petr Lukes, Ales Kucera, Pavel Cudlin
Summary: The study evaluates the effects of environmental predispositions on the damage to mountain forests. It finds that management, environmental predispositions, and soil have different levels of influence on forest NDVI.
JOURNAL OF MOUNTAIN SCIENCE
(2022)
Article
Agronomy
Jiri Tomicek, Jan Misurec, Petr Lukes, Marketa Potuckova
Summary: This study proposes an approach for calculating Leaf Area Indices (LAIs) for agronomic crops using satellite data. The approach was tested on dominant crops in the Czech Republic and achieved good results. The method can be used to create a dense LAI time series with high potential for precision agriculture.
Article
Agronomy
Petri R. Forsstrom, Aarne Hovi, Jussi Juola, Miina Rautiainen
Summary: The study investigates the relationship between light availability at forest floor and its spectral reflectance properties and fractional cover across boreal and temperate Europe. The results show that tree canopy structure is linked to the vegetation composition and spectral reflectance properties of forest floor, and these relationships differ between forest biomes.
AGRICULTURAL AND FOREST METEOROLOGY
(2023)
Article
Ecology
Sini-Selina Salko, Jussi Juola, Iuliia Burdun, Harri Vasander, Miina Rautiainen
Summary: The study highlights the importance of using spectral data in the shortwave infrared region (1100-2500 nm) for remote sensing applications, especially in monitoring the changes in wetland conditions.
ECOLOGY AND EVOLUTION
(2023)
Article
Agronomy
Daniel Schraik, Di Wang, Aarne Hovi, Miina Rautiainen
Summary: In this study, a method was developed to measure the clumping index (CI) of forest stands using terrestrial lidar data. Measurements of CI and STARf were conducted on 38 forest stands in Finland, Estonia, and Czechia to study their natural range and relationships with other forest variables and Landsat 8 OLI surface reflectance. It was found that CI was closely correlated with surface reflectance in conifer forests.
AGRICULTURAL AND FOREST METEOROLOGY
(2023)
Article
Forestry
Aarne Hovi, Petr Lukes, Lucie Homolova, Jussi Juola, Miina Rautiainen
Summary: This research assesses the geographical variability of Norway spruce needle spectra across different latitudes in Europe and finds that the variability is small compared to previous measurement campaigns or variability between plant functional types.
Article
Forestry
Nea Kuusinen, Aarne Hovi, Miina Rautiainen
Summary: Spectral mixture analysis was used to estimate the contribution of woody elements to tree level reflectance in boreal forest stands in Finland. The study found that the contribution of different woody elements varied and had a weak connection to plot level forest variables.
Article
Forestry
Daniel Schraik, Aarne Hovi, Miina Rautiainen
Summary: Terrestrial laser scanning provides a unique opportunity to study forest canopy structure, but estimating leaf area density is biased by the physical dimensions of laser beams. Research found that conifer foliage had a lower average per-pulse cover fraction than broadleaved foliage, indicating an increased number of partial hits in conifer foliage.
Article
Multidisciplinary Sciences
Aarne Hovi, Petri R. Forsstrom, Giulia Ghielmetti, Michael E. Schaepman, Miina Rautiainen
Summary: This article presents a dataset of multiangular scattering properties of small trees in visible, near-infrared, and shortwave-infrared wavelengths, along with supporting auxiliary data. The data, collected from three common European tree species, are valuable for modeling the shortwave reflectance characteristics of small trees and potentially forests, and can benefit climate modeling and remote sensing data interpretation.
Article
Environmental Sciences
Ruonan Chen, Liangyun Liu, Xinjie Liu, Zhunqiao Liu, Lianhong Gu, Uwe Rascher
Summary: This study presents methods to accurately estimate sub-daily GPP from SIF in evergreen needleleaf forests and demonstrates that the interactions among light, canopy structure, and leaf physiology regulate the SIF-GPP relationship at the canopy scale.
REMOTE SENSING OF ENVIRONMENT
(2024)
Article
Environmental Sciences
Daniel L. Goldberg, Madankui Tao, Gaige Hunter Kerr, Siqi Ma, Daniel Q. Tong, Arlene M. Fiore, Angela F. Dickens, Zachariah E. Adelman, Susan C. Anenberg
Summary: A novel method is applied in this study to directly use satellite data to evaluate the spatial patterns of urban NOx emissions inventories. The results show that the 108 spatial surrogates used by NEMO are generally appropriate, but there may be underestimation in areas with dense intermodal facilities and overestimation in wealthy communities.
REMOTE SENSING OF ENVIRONMENT
(2024)
Article
Environmental Sciences
Zhuoyue Hu, Xiaoyan Li, Liyuan Li, Xiaofeng Su, Lin Yang, Yong Zhang, Xingjian Hu, Chun Lin, Yujun Tang, Jian Hao, Xiaojin Sun, Fansheng Chen
Summary: This paper proposes a whisk-broom imaging method using a long-linear-array detector and high-precision scanning mirror to achieve high-resolution and wide-swath thermal infrared data. The method has been implemented in the SDGs satellite and has shown promising test results.
REMOTE SENSING OF ENVIRONMENT
(2024)
Article
Environmental Sciences
Dandan Wang, Leiqiu Hu, James A. Voogt, Yunhao Chen, Ji Zhou, Gaijing Chang, Jinling Quan, Wenfeng Zhan, Zhizhong Kang
Summary: This study evaluates different schemes for determining model coefficients to quantify and correct the anisotropic impact from remote sensing LST for urban applications. The schemes have consistent results and accurately estimate parameter values, facilitating the broadening of parametric models.
REMOTE SENSING OF ENVIRONMENT
(2024)
Article
Environmental Sciences
Jamie Tolan, Hung - Yang, Benjamin Nosarzewski, Guillaume Couairon, Huy V. Vo, John Brandt, Justine Spore, Sayantan Majumdar, Daniel Haziza, Janaki Vamaraju, Theo Moutakanni, Piotr Bojanowski, Tracy Johns, Brian White, Tobias Tiecke, Camille Couprie
Summary: Vegetation structure mapping is crucial for understanding the global carbon cycle and monitoring nature-based approaches to climate adaptation and mitigation. This study presents the first high-resolution canopy height maps for California and Sao Paulo, achieved through the use of very high resolution satellite imagery and aerial lidar data. The maps provide valuable tools for forest structure assessment and land use monitoring.
REMOTE SENSING OF ENVIRONMENT
(2024)
Article
Environmental Sciences
Regina Eckert, Steffen Mauceri, David R. Thompson, Jay E. Fahlen, Philip G. Brodrick
Summary: In this paper, a mathematical framework is proposed to improve the retrieval of surface reflectance and atmospheric parameters by leveraging the expected spatial smoothness of the atmosphere. Experimental results show that this framework can reduce the surface reflectance retrieval error and surface-related biases.
REMOTE SENSING OF ENVIRONMENT
(2024)
Article
Environmental Sciences
Chongya Jiang, Kaiyu Guan, Yizhi Huang, Maxwell Jong
Summary: This study presents the Field Rover method, which uses vehicle-mounted cameras to collect ground truth data on crop harvesting status. The machine learning approach and remote sensing technology are employed to upscale the results to a regional scale. The accuracy of the remote sensing method in predicting crop harvesting dates is validated through comparison with satellite data.
REMOTE SENSING OF ENVIRONMENT
(2024)
Article
Environmental Sciences
Oksana V. Lunina, Anton A. Gladkov, Alexey V. Bochalgin
Summary: In this study, an unmanned aerial vehicle (UAV) was used to detect and map surface discontinuities with displacements of a few centimeters, indicating the presence of initial geological deformations. The study found that sediments of alluvial fans are susceptible to various tectonic and exogenous deformational processes, and the interpretation of ultra-high resolution UAV images can help recognize low-amplitude brittle deformations at an early stage. UAV surveys are critical for discerning neotectonic activity and its related hazards over short observation periods.
REMOTE SENSING OF ENVIRONMENT
(2024)
Article
Environmental Sciences
Feng Zhao, Weiwei Ma, Jun Zhao, Yiqing Guo, Mateen Tariq, Juan Li
Summary: This study presents a data-driven approach to reconstruct the terrestrial SIF spectrum using measurements from the TROPOMI instrument on Sentinel-5 precursor mission. The reconstructed SIF spectrum shows improved spatiotemporal distributions and demonstrates consistency with other datasets, indicating its potential for better understanding of the ecosystem function.
REMOTE SENSING OF ENVIRONMENT
(2024)
Article
Environmental Sciences
Stephen Stehman, John E. Wagner
Summary: This article investigates optimal sample allocation in stratified random sampling for estimation of accuracy and proportion of area in applications where the target class is rare. The study finds that precision of estimated accuracy has a stronger impact on sample allocation than estimation of proportion of area, and the trade-offs among these estimates become more pronounced as the target class becomes rarer. The results provide quantitative evidence to guide sample allocation decisions in specific applications.
REMOTE SENSING OF ENVIRONMENT
(2024)
Article
Environmental Sciences
Jingyao Zheng, Tianjie Zhao, Haishen Lu, Defu Zou, Nemesio Rodriguez-Fernandez, Arnaud Mialon, Philippe Richaume, Jianshe Xiao, Jun Ma, Lei Fan, Peilin Song, Yonghua Zhu, Rui Li, Panpan Yao, Qingqing Yang, Shaojie Du, Zhen Wang, Zhiqing Peng, Yuyang Xiong, Zanpin Xing, Lin Zhao, Yann Kerr, Jiancheng Shi
Summary: Soil moisture and freeze/thaw (F/T) play a crucial role in water and heat exchanges at the land-atmosphere interface. This study reports the establishment of a wireless sensor network for soil moisture and temperature over the permafrost region of Tibetan Plateau. Satellite-based surface soil moisture (SSM) and F/T products were evaluated using ground-based measurements. The results show the reliability of L-band passive microwave SSM and F/T products, while existing F/T products display earlier freezing and later thawing, leading to unsatisfactory accuracy.
REMOTE SENSING OF ENVIRONMENT
(2024)
