Remote Sensing of Environment最新文献

{"title":"A physically based differentiable radiative transfer model (DRTM) for land surface optical and biochemical parameters retrieval","authors":"Lisai Cao ,&nbsp;Zhijun Zhen ,&nbsp;Shengbo Chen ,&nbsp;Tiangang Yin","doi":"10.1016/j.rse.2025.114764","DOIUrl":"10.1016/j.rse.2025.114764","url":null,"abstract":"<div><div>The differential path tracing method and automatic differentiation can effectively calculate the derivatives of the loss function, enabling the estimation of surface properties such as reflectivity and transmissivity from sensor images. However, their full potential has not been completely explored in remote sensing. We developed a differentiable radiative transfer model (DRTM) to efficiently simulate and retrieve leaf optical properties, leaf biochemical components, and sensor observation angles from passive remote sensing imagery. The modeling accuracy is verified using various three-dimensional (3D) heterogeneous landscapes, including natural vegetation-covered and artificial urban landscapes. The forward modeling part of DRTM has proved to be faster and more efficient in computer resource usage. In addition, DRTM demonstrated a much more effective adaptation of deep learning than the traditional look-up table method, to better resolve the most challenging inversions from canopy level to foliar level in vegetation remote sensing. In this context, DRTM can potentially address various inverse challenges in remote sensing within a unified framework.</div></div>","PeriodicalId":417,"journal":{"name":"Remote Sensing of Environment","volume":"325 ","pages":"Article 114764"},"PeriodicalIF":11.1,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143872463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection of multi-year ex-fast ice in the Weddell Sea, Antarctica, using ICESat-2 satellite altimeter data","authors":"Younghyun Koo ,&nbsp;Hongjie Xie ,&nbsp;Walter N. Meier ,&nbsp;Stephen F. Ackley ,&nbsp;Nathan T. Kurtz","doi":"10.1016/j.rse.2025.114750","DOIUrl":"10.1016/j.rse.2025.114750","url":null,"abstract":"<div><div>Landfast ice, sea ice fastened to coastal land or ice shelves, generally undergoes distinctive thermodynamic growth and less active dynamic deformation due to its prolonged attachment to the land, resulting in a thicker and smoother surface compared to drifting pack ice. In 2019, large landfast ice floes were detached from the Ronne Ice Shelf, and the broken pieces started to drift into the Weddell Sea. This study employs a random forest (RF) machine learning model to detect these ex-fast ice floes using six key variables from the ICESat-2 ATL10 sea ice freeboard product: freeboard, Gaussian width of photon height distribution, standard deviation of freeboard, floe length, modal freeboard, and sea ice concentration. The RF model achieves an overall accuracy of 99 % in detecting ex-fast ice, effectively capturing the drift, freeboard distribution, and size distribution of ex-fast ice floes across the western Weddell Sea in 2019. Among six variables, freeboard, standard deviation of freeboard, and Gaussian width of photon height distribution contribute over 94 % to the model performance. Furthermore, the detection of ex-fast ice improves the quantification of sea ice topographical features derived from ICESat-2, including modal freeboard, ridge fraction, and surface roughness. This study highlights the effectiveness of discriminating heterogeneous ex-fast ice from typical pack ice to enhance sea ice measurements using ICESat-2 satellite altimeter data.</div></div>","PeriodicalId":417,"journal":{"name":"Remote Sensing of Environment","volume":"325 ","pages":"Article 114750"},"PeriodicalIF":11.1,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143864848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An integrating pre-temperature description method for generating all-weather land surface temperature via passive microwave and thermal infrared remote sensing","authors":"Weizhen Ji ,&nbsp;Yunhao Chen ,&nbsp;Xiaohui Li ,&nbsp;Kangning Li ,&nbsp;Haiping Xia ,&nbsp;Ji Zhou ,&nbsp;Han Gao","doi":"10.1016/j.rse.2025.114767","DOIUrl":"10.1016/j.rse.2025.114767","url":null,"abstract":"<div><div>Integrating passive microwave (PMW) and thermal infrared (TIR) remote sensing to generate all-weather land surface temperature (LST) is essential for effective land thermal monitoring. Previous studies have attempted to adapt TIR-interactive kernel-driven downscaling techniques into the PMW-TIR integration process. However, large-scale spans often introduce significant uncertainties in the generated LST, potentially leading to spatial streaks. To address these challenges, it is critical to introduce a reliable temperature representation at the target resolution to generate accurate all-weather LST. In this study, we propose an integrated pre-temperature description model (ITDM) comprising three modules. The first module is a machine learning-based bias correction-driven generation module (BCDM), which generates relatively precise LST, particularly during the daytime, though it may smooth some spatial textures in certain regions. The second module, a spatial detail-aware generation module (SDAM), utilizes an annual temperature cycle model-based LST as a temperature description, ensuring spatial consistency in the generated LST. The third module integrates the two previous modules, addressing their differences to optimize the final output. Validation results based on MODIS LST indicate that the proposed method achieves a daytime root mean squared error (RMSE) of 3.20 K and a standard deviation of bias (STD) of 3.08 K. For nighttime, the RMSE and STD are 2.24 K and 2.15 K, respectively. Additionally, ten in-situ measurements reveal an average RMSE of 3.90 K in the daytime and 3.34 K in the nighttime. Comparative results with two other advanced methods based on MODIS LST and in-situ LST show that the proposed approach reduces RMSE by 0.04–0.91 K and mitigates streaking phenomena more effectively. The study also discusses feature importance, module performance, and the extendibility of the method. The proposed model significantly contributes to the generation of high-quality all-weather LST.</div></div>","PeriodicalId":417,"journal":{"name":"Remote Sensing of Environment","volume":"324 ","pages":"Article 114767"},"PeriodicalIF":11.1,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143860475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The relationship between the ratio of far-red to red leaf SIF and leaf chlorophyll content: Theoretical derivation and experimental validation","authors":"Runfei Zhang ,&nbsp;Peiqi Yang ,&nbsp;Shan Xu ,&nbsp;Long Li ,&nbsp;Tingrui Guo ,&nbsp;Dalei Han ,&nbsp;Jing Liu","doi":"10.1016/j.rse.2025.114762","DOIUrl":"10.1016/j.rse.2025.114762","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Leaf chlorophyll content (LCC) is an important indicator of photosynthetic capacity. Sun-induced chlorophyll fluorescence (SIF) is an optical signal emitted from the leaf interior, providing a unique technique for accurately estimating LCC. The far-red to red ratio of chlorophyll fluorescence (&lt;em&gt;F&lt;/em&gt;&lt;sub&gt;ratio&lt;/sub&gt;) has been used to empirically estimate LCC in some previous studies. While these studies support the use of the &lt;em&gt;F&lt;/em&gt;&lt;sub&gt;ratio&lt;/sub&gt; for LCC estimation, its theoretical underpinning remains less well-defined and its effectiveness across a wider range of scenarios remains unclear. In this study, we established the relationship between the &lt;em&gt;F&lt;/em&gt;&lt;sub&gt;ratio&lt;/sub&gt; and LCC using the light use efficiency (LUE)-based SIF model and spectral invariant radiative transfer theory. Firstly, the LUE-based SIF model demonstrates that the change in the leaf &lt;em&gt;F&lt;/em&gt;&lt;sub&gt;ratio&lt;/sub&gt; is controlled by the ratio of the fluorescence escape fraction (i.e., &lt;em&gt;f&lt;/em&gt;&lt;sub&gt;&lt;em&gt;esc&lt;/em&gt;&lt;/sub&gt; from the photosystem to the leaf surface) at the corresponding bands. Secondly, a &lt;em&gt;f&lt;/em&gt;&lt;sub&gt;&lt;em&gt;esc&lt;/em&gt;&lt;/sub&gt; modeling approach is presented using the spectral invariant theory and thus the &lt;em&gt;f&lt;/em&gt;&lt;sub&gt;&lt;em&gt;esc&lt;/em&gt;&lt;/sub&gt; ratio is linked to LCC. Theoretical analysis shows that the &lt;em&gt;F&lt;/em&gt;&lt;sub&gt;ratio&lt;/sub&gt; has a strong correlation with LCC, which explains over 90 % of the variation in &lt;em&gt;F&lt;/em&gt;&lt;sub&gt;ratio&lt;/sub&gt;. Both experimental measurements and model simulations from a radiative transfer model Fluspect were used to validate the relationship between LCC and three &lt;em&gt;F&lt;/em&gt;&lt;sub&gt;ratio&lt;/sub&gt; (i.e., &lt;span&gt;&lt;math&gt;&lt;msubsup&gt;&lt;mi&gt;F&lt;/mi&gt;&lt;mtext&gt;ratio&lt;/mtext&gt;&lt;mo&gt;↑&lt;/mo&gt;&lt;/msubsup&gt;&lt;/math&gt;&lt;/span&gt;, &lt;span&gt;&lt;math&gt;&lt;msubsup&gt;&lt;mi&gt;F&lt;/mi&gt;&lt;mtext&gt;ratio&lt;/mtext&gt;&lt;mo&gt;↓&lt;/mo&gt;&lt;/msubsup&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;msubsup&gt;&lt;mi&gt;F&lt;/mi&gt;&lt;mtext&gt;ratio&lt;/mtext&gt;&lt;mi&gt;tot&lt;/mi&gt;&lt;/msubsup&gt;&lt;/math&gt;&lt;/span&gt;), which were derived from the upward and downward SIF of leaves, as well as the total SIF observed from both sides. The Fluspect simulations were used to assess the sensitivity of the &lt;em&gt;F&lt;/em&gt;&lt;sub&gt;ratio&lt;/sub&gt;-LCC relationship to the leaf structure. Two types of experimental measurements, including the field measurements of three crops and the laboratory measurements of 20 tundra plants, were employed to examine the species dependence of the &lt;em&gt;F&lt;/em&gt;&lt;sub&gt;ratio&lt;/sub&gt;-LCC relationship. The performance of &lt;em&gt;F&lt;/em&gt;&lt;sub&gt;ratio&lt;/sub&gt; for LCC estimation was evaluated and compared with spectral indices and the PROSPECT model using the experimental measurements and leave-one-out cross-validation (LOOCV) approach. Both the Fluspect simulations and the experimental measurements indicate that the &lt;em&gt;F&lt;/em&gt;&lt;sub&gt;ratio&lt;/sub&gt; is strongly correlated with LCC for a wide range of leaf scenarios. The &lt;em&gt;F&lt;/em&gt;&lt;sub&gt;ratio&lt;/sub&gt;-LCC relationship remains relatively stable across different leaf structures and plant species, since the relationship is almost consistent. The LOOCV of experimental measurem","PeriodicalId":417,"journal":{"name":"Remote Sensing of Environment","volume":"324 ","pages":"Article 114762"},"PeriodicalIF":11.1,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143855876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Machine learning-based generation of high-resolution 3D full-coverage aerosol distribution data over China using multisource data","authors":"Wenze Li ,&nbsp;Wenchao Han ,&nbsp;Jiachen Meng ,&nbsp;Zipeng Dong ,&nbsp;Jun Xu ,&nbsp;Qimeng Wang ,&nbsp;Lulu Yuan ,&nbsp;Han Wang ,&nbsp;Zhongzhi Zhang ,&nbsp;Miaomiao Cheng","doi":"10.1016/j.rse.2025.114772","DOIUrl":"10.1016/j.rse.2025.114772","url":null,"abstract":"<div><div>Aerosol pollution significantly influences the interaction between solar radiation and the earth's atmosphere and seriously threatens human health. Numerous studies have applied machine learning models such as Extreme Gradient Boosting (XGBoost) and Light Gradient Boosting Machine (LightGBM) to estimate aerosol-related parameters, including aerosol optical depth and particulate matter concentrations (e.g., PM_2.5). However, current aerosol products primarily provide horizontal or spatially discontinuous vertical data, lacking comprehensive three-dimensional (3D) coverage. To address this gap, we developed the XGBoost-LightGBM-Wavelet (XLW) model, integrating XGBoost, LightGBM, and wavelet transforms to merge multisource data. This approach, for the first time, produced high-resolution, three-dimensional, full-coverage aerosol distribution data for China in 2015. The model outputs a dataset of aerosol spatial distribution with a horizontal resolution of 0.05°, and 167 layers within 10 km in the vertical direction. The XLW model demonstrates excellent predictive ability, effectively filling gaps in aerosol distribution. It enhances signal continuity and strengthens lower-layer signals, closely matching ground LiDAR observations and providing a more accurate representation compared to the Cloud-Aerosol LiDAR and Infrared Pathfinder Satellite Observation (CALIPSO) data. The dataset accurately reveals the 3D distribution of aerosols, which is meaningful for a comprehensive study of aerosol distribution at different altitudes in various regions. At 300 m height above ground level, the most polluted regions are the North China Plain and the Yangtze River Delta region, with an average aerosol extinction coefficient (AEC) of 0.34 and 0.40 km⁻¹, respectively. As the height increases to 1 km, the average AEC notably decreases to 0.23 and 0.24 km⁻¹ in the North China Plain and the Yangtze River Delta. By 3 km, aerosol distribution becomes sparse over most regions of China. For the vertical variations of aerosol distributions in typical cities, in the North China Plain and Yangtze River Delta, aerosol concentrations consistently decrease from the near-surface to 4 km. However, in the Pearl River Delta, aerosol concentrations decrease consistently from 0 to 2 km, with relatively stable between 2 and 3 km. Above 4 km, aerosol concentrations are nearly negligible in all typical cities. The XLW model can accurately produce a high-resolution, 3D, full-coverage aerosol spatial distribution dataset, which is vital for conducting thorough studies on aerosol transport, aerosol radiative effects, and climate change.</div></div>","PeriodicalId":417,"journal":{"name":"Remote Sensing of Environment","volume":"324 ","pages":"Article 114772"},"PeriodicalIF":11.1,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143851386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"GDCM: Generalized data completion model for satellite observations","authors":"Haoyu Wang ,&nbsp;Yinfei Zhou ,&nbsp;Xiaofeng Li","doi":"10.1016/j.rse.2025.114760","DOIUrl":"10.1016/j.rse.2025.114760","url":null,"abstract":"<div><div>Ocean remote sensing data is crucial in understanding the global climate system. Due to satellite orbital coverage gaps and cloud cover, satellite ocean remote sensing products have significant data gaps. This paper introduces a Generalized Data Completion Model (GDCM) based on deep learning to reconstruct gap-free and cloud-free key oceanic variables such as sea surface temperature (SST), wind speed, water vapor, cloud liquid water, and precipitation rate derived from polar-orbiting satellite sensors including Advanced Microwave Scanning Radiometer 2 (AMSR2), the Special Sensor Microwave Imager (SSMI), and the Moderate Resolution Imaging Spectroradiometer (MODIS). Utilizing Convolutional Neural Networks (CNNs) and attention mechanisms, the GDCM model effectively leverages spatio-temporal information within remote sensing data to fill in missing regions accurately. We use reanalysis data to simulate various data missing scenarios during model training for model development. We tested the model with the US East Coast region's global-coverage AMSR2/SSMI and local-coverage MODIS datasets. The experiments demonstrate that the GDCM model successfully and precisely completes the data for different satellites and types of missing data. To enable the model to capture enough data for the dynamical change patterns, we used seven consecutive days of observation data as inputs to improve the model's data-completion ability, significantly enhancing the handling of MODIS SST missing data due to cloud cover. When the input data's duration increased from one day to seven days, the model's R² value improved from 0.062 to 0.93, and the Root Mean Square Difference (RMSD) decreased from 6.58 to 0.92. Besides the model framework design, we implemented the incremental learning training strategy to enhance the model's data completion capability for different types of missing data, especially for SST data from AMSR2 satellites. The model's completed SST data R² value improved from 0.93 to 0.99, and the RMSD decreased from 2.64 °C to 0.50 °C. The Mean Absolute Difference (MAD) of water vapor data decreased from 0.88 kg/m² to 0.76 kg/m², and the RMSD decreased from 1.39 kg/m² to 1.27 kg/m². This study provides a generalized new solution to the problem of missing ocean data at different resolutions, contributing to a more comprehensive and supporting ocean science research and related applications.</div></div>","PeriodicalId":417,"journal":{"name":"Remote Sensing of Environment","volume":"324 ","pages":"Article 114760"},"PeriodicalIF":11.1,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143838424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-resolution anthropogenic emission inventories with deep learning in northern South America","authors":"Franz Pablo Antezana Lopez ,&nbsp;Alejandro Casallas ,&nbsp;Guanhua Zhou ,&nbsp;Kai Zhang ,&nbsp;Guifei Jing ,&nbsp;Aamir Ali ,&nbsp;Ellie Lopez-Barrera ,&nbsp;Luis Carlos Belalcazar ,&nbsp;Nestor Rojas ,&nbsp;Hongzhi Jiang","doi":"10.1016/j.rse.2025.114761","DOIUrl":"10.1016/j.rse.2025.114761","url":null,"abstract":"<div><div>Air quality in northern South America faces significant challenges due to insufficient high-resolution emission inventories and sparse atmospheric studies. This study addresses these gaps by developing a novel framework that integrates high-resolution nighttime light data from SDGSAT-1 and multisource remote sensing datasets with deep learning techniques to downscale emission inventories. The refined inventories are coupled with meteorological inputs into the Weather Research and Forecasting (WRF-Chem) model, enabling precise simulation of pollutant dynamics. Validated against ground measurements from Colombia's SISAIRE monitoring network, demonstrates significant improvements in spatiotemporal accuracy, particularly for particulate matter (PM) and nitrogen dioxide (NO₂) with error reductions of 22–30 % and correlation coefficients increasing from 0.68 to 0.85. These findings underscore the critical role of satellite-enhanced inventories in resolving localized emission patterns and seasonal variability, such as dry-season PM₁₀ spikes (150 % increase from wildfires). The framework provides policymakers with actionable insights to prioritize mitigation in rapidly urbanizing regions and manage transboundary pollution. By bridging data scarcity gaps, this replicable methodology offers transformative potential for global air quality management and public health protection, advocating for expanded ground monitoring networks and real-time satellite data integration in future applications.</div></div>","PeriodicalId":417,"journal":{"name":"Remote Sensing of Environment","volume":"324 ","pages":"Article 114761"},"PeriodicalIF":11.1,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143838357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimating NOx emissions of individual ships from TROPOMI NO2 plumes","authors":"T. Christoph V.W. Riess ,&nbsp;K. Folkert Boersma ,&nbsp;Aude Prummel ,&nbsp;Bart J.H. van Stratum ,&nbsp;Jos de Laat ,&nbsp;Jasper van Vliet","doi":"10.1016/j.rse.2025.114734","DOIUrl":"10.1016/j.rse.2025.114734","url":null,"abstract":"<div><div>Maritime transportation is a substantial contributor to anthropogenic NO<span><math><msub><mrow></mrow><mrow><mi>x</mi></mrow></msub></math></span> emissions and coastal air pollution. Recognizing this, the International Maritime Organization (IMO) has steadily implemented stepwise stricter emission standards for ships in recent years. However, monitoring emissions from sea-bound vessels poses inherent challenges, prompting the exploration of satellite observations as a promising solution. Here we use TROPOMI measurements of NO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> plumes together with information on ship position and identity, and atmospheric models to quantify the NO<span><math><msub><mrow></mrow><mrow><mi>x</mi></mrow></msub></math></span> emissions of 130 plumes from individual ships in the eastern Mediterranean Sea in 2019. Because most of the emitted NO<span><math><msub><mrow></mrow><mrow><mi>x</mi></mrow></msub></math></span> is in the form of NO, which is not immediately converted into detectable NO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>, plumes show their NO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> maximum some 15-30 km downwind of the ship’s stack. Further downwind NO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> decreases because of plume dispersion and photochemical oxidation. Background ozone and wind speed play a significant role both in detectability of the NO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> plume and the relationship between NO<span><math><msub><mrow></mrow><mrow><mi>x</mi></mrow></msub></math></span> emissions and observed NO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>, explaining the good detection conditions in the eastern Mediterranean summertime, where ozone levels are high. Taking such effects of emissions, dispersion, entrainment, and in-plume chemistry in full account, we find emission strengths of 10-317 g (NO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>) s⁻¹. We then calculate emission factors of the detected ship plumes using AIS and ship specific data and find that newer Tier II ships have higher emission factors compared to older Tier I ships. This is especially the case when running at lower engine loads, which is the most frequently observed mode of operation in our ensemble. Additionally, at the time of detection around half of the emission factors detected for Tier II ships lie above the IMO weighted average limits. The presented method sets the stage for automated ship emission monitoring at sea, contributing to better air quality management.</div></div>","PeriodicalId":417,"journal":{"name":"Remote Sensing of Environment","volume":"324 ","pages":"Article 114734"},"PeriodicalIF":11.1,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143838356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A gradient-based nonlinear multi-pixel physical method for simultaneously separating component temperature and emissivity from nonisothermal mixed pixels with DART","authors":"Zhijun Zhen ,&nbsp;Shengbo Chen ,&nbsp;Nicolas Lauret ,&nbsp;Abdelaziz Kallel ,&nbsp;Tiangang Yin ,&nbsp;Jonathan León-Tavares ,&nbsp;Biao Cao ,&nbsp;Jean-Philippe Gastellu-Etchegorry","doi":"10.1016/j.rse.2025.114738","DOIUrl":"10.1016/j.rse.2025.114738","url":null,"abstract":"<div><div>Component temperature and emissivity are crucial for understanding plant physiology and urban thermal dynamics. However, existing thermal infrared unmixing methods face challenges in simultaneous retrieval and multi-component analysis. We propose Thermal Remote sensing Unmixing for Subpixel Temperature and emissivity with the Discrete Anisotropic Radiative Transfer model (TRUST-DART), a gradient-based multi-pixel physical method that simultaneously separates component temperature and emissivity from non-isothermal mixed pixels over urban areas. TRUST-DART utilizes the DART model and requires inputs including at-surface radiance imagery, downwelling sky irradiance, a 3D mock-up with component classification, and standard DART parameters (<em>e.g.</em>, spatial resolution and skylight ratio). This method produces maps of component emissivity and temperature. The accuracy of TRUST-DART is evaluated using both vegetation and urban scenes, employing Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) images and DART-simulated pseudo-ASTER images. Results show a residual radiance error is approximately 0.05 W/(m²·sr). In absence of the co-registration and sensor noise errors, the median residual error of emissivity is approximately 0.02, and the median residual error of temperature is within 1 K. This novel approach significantly advances our ability to analyze thermal properties of urban areas, offering potential breakthroughs in urban environmental monitoring and planning. The source code of TRUST-DART is distributed together with DART (<span><span>https://dart.omp.eu</span><svg><path></path></svg></span>).</div></div>","PeriodicalId":417,"journal":{"name":"Remote Sensing of Environment","volume":"324 ","pages":"Article 114738"},"PeriodicalIF":11.1,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143838423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Slip surface, volume and evolution of active landslide groups in Gongjue County, eastern Tibetan Plateau from 15-year InSAR observations","authors":"Bo Chen ,&nbsp;Zhenhong Li ,&nbsp;Chuang Song ,&nbsp;Chen Yu ,&nbsp;Roberto Tomás ,&nbsp;Jiantao Du ,&nbsp;Xinlong Li ,&nbsp;Adrien Mugabushaka ,&nbsp;Wu Zhu ,&nbsp;Jianbing Peng","doi":"10.1016/j.rse.2025.114763","DOIUrl":"10.1016/j.rse.2025.114763","url":null,"abstract":"<div><div>Landslides stand as a prevalent geological risk in mountainous areas, presenting substantial danger to human habitation. The slip surface (SSF), volume, type and evolution of landslides constitute crucial information from which to understand landslide mechanisms and assess landslide risk. However, current methods for obtaining this information, relying primarily on field surveys, are usually time-consuming, labor-intensive and costly, and are more applicable to individual landslides than large-scale landslide groups. To tackle these challenges, we present a novel method utilizing multi-orbit Synthetic Aperture Radar (SAR) data to deduce the SSF, volume and type of active landslides. In this method, the SSF of landslides over a wide area is determined from three-dimensional deformation fields by assuming that the most authentic direction of the landslide movement aligns parallel to the SSF, on the basis of which the volume and type of active landslides can also be inferred. This approach was utilized with landslide groups in Gongjue County (LGGC), situated in the eastern Tibetan Plateau, which pose grave peril to community members and critical construction along the upstream/downstream of the Jinsha River. Firstly, SAR images were gathered and interferometrically processed from four separate platforms, spanning the period from July 2007 to August 2022. Then, three-dimensional displacement time series were inverted based on Interferometric Synthetic Aperture Radar (InSAR) observations and a topography-constrained model, from which the SSF, volume and type were determined using our proposed method. Finally, the Tikhonov regularization method was applied to reconstruct 15-year displacement time series along the sliding surface, and potential driving factors of landslide motion were identified. Results indicate that 53 landslides were detected in the LGGC region, of which ∼70 % were active and complex landslides with maximum cumulative displacement along the sliding surface reaching 1.5 m over the past ∼15 years. In addition, the deepest SSF of these landslides was found to reach 114 m, with volumes ranging from 1.66 × 10⁵ m³ to 1.72 × 10⁸ m³. Independent in-situ measurements validate the reliability of the SSF obtained in this study. More particularly, we found that the 2018 failure of the Baige landslide (approximately 50 km from LGCC) had caused persistent acceleration to those wading landslides, highlighting the prolonged impact of external factors on landslide evolution. These insights provide a deeper understanding of landslide dynamics and mechanisms, which is crucial when implementing early warning systems and forecasting future failure events.</div></div>","PeriodicalId":417,"journal":{"name":"Remote Sensing of Environment","volume":"324 ","pages":"Article 114763"},"PeriodicalIF":11.1,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143833479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}