Pub Date : 2025-02-01DOI: 10.1016/j.isprsjprs.2025.01.016
Maria Gonzalez-Calabuig, Miguel-Ángel Fernández-Torres, Gustau Camps-Valls
Earth observation from satellite sensors offers the possibility to monitor natural ecosystems by deriving spatially explicit and temporally resolved biogeophysical parameters. Optical remote sensing, however, suffers from missing data mainly due to the presence of clouds, sensor malfunctioning, and atmospheric conditions. This study proposes a novel deep learning architecture to address gap filling of satellite reflectances, more precisely the visible and near-infrared bands, and illustrates its performance at high-resolution Sentinel-2 data. We introduce GANFilling, a generative adversarial network capable of sequence-to-sequence translation, which comprises convolutional long short-term memory layers to effectively exploit complete dependencies in space–time series data. We focus on Europe and evaluate the method’s performance quantitatively (through distortion and perceptual metrics) and qualitatively (via visual inspection and visual quality metrics). Quantitatively, our model offers the best trade-off between denoising corrupted data and preserving noise-free information, underscoring the importance of considering multiple metrics jointly when assessing gap filling tasks. Qualitatively, it successfully deals with various noise sources, such as clouds and missing data, constituting a robust solution to multiple scenarios and settings. We also illustrate and quantify the quality of the generated product in the relevant downstream application of vegetation greenness forecasting, where using GANFilling enhances forecasting in approximately 70% of the considered regions in Europe. This research contributes to underlining the utility of deep learning for Earth observation data, which allows for improved spatially and temporally resolved monitoring of the Earth surface.
{"title":"Generative networks for spatio-temporal gap filling of Sentinel-2 reflectances","authors":"Maria Gonzalez-Calabuig, Miguel-Ángel Fernández-Torres, Gustau Camps-Valls","doi":"10.1016/j.isprsjprs.2025.01.016","DOIUrl":"10.1016/j.isprsjprs.2025.01.016","url":null,"abstract":"<div><div>Earth observation from satellite sensors offers the possibility to monitor natural ecosystems by deriving spatially explicit and temporally resolved biogeophysical parameters. Optical remote sensing, however, suffers from missing data mainly due to the presence of clouds, sensor malfunctioning, and atmospheric conditions. This study proposes a novel deep learning architecture to address gap filling of satellite reflectances, more precisely the visible and near-infrared bands, and illustrates its performance at high-resolution Sentinel-2 data. We introduce GANFilling, a generative adversarial network capable of sequence-to-sequence translation, which comprises convolutional long short-term memory layers to effectively exploit complete dependencies in space–time series data. We focus on Europe and evaluate the method’s performance <em>quantitatively</em> (through distortion and perceptual metrics) and <em>qualitatively</em> (via visual inspection and visual quality metrics). Quantitatively, our model offers the best trade-off between denoising corrupted data and preserving noise-free information, underscoring the importance of considering multiple metrics jointly when assessing gap filling tasks. Qualitatively, it successfully deals with various noise sources, such as clouds and missing data, constituting a robust solution to multiple scenarios and settings. We also illustrate and quantify the quality of the generated product in the relevant downstream application of vegetation greenness forecasting, where using GANFilling enhances forecasting in approximately 70% of the considered regions in Europe. This research contributes to underlining the utility of deep learning for Earth observation data, which allows for improved spatially and temporally resolved monitoring of the Earth surface.</div></div>","PeriodicalId":50269,"journal":{"name":"ISPRS Journal of Photogrammetry and Remote Sensing","volume":"220 ","pages":"Pages 637-648"},"PeriodicalIF":10.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143035306","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}
Pub Date : 2025-02-01DOI: 10.1016/j.isprsjprs.2025.01.010
Tao Sun , Yan Hao , Shengyu Huang , Silvio Savarese , Konrad Schindler , Marc Pollefeys , Iro Armeni
Building 3D geometric maps of man-made spaces is a well-established and active field that is fundamental to numerous computer vision and robotics applications. However, considering the continuously evolving nature of built environments, it is essential to question the capabilities of current mapping efforts in handling temporal changes. In addition to the above, the ability to create spatiotemporal maps holds significant potential for achieving sustainability and circularity goals. Existing mapping approaches focus on small changes, such as object relocation within common living spaces or self-driving car operation in outdoor spaces; all cases where the main structure of the scene remains fixed. Consequently, these approaches fail to address more radical change in the structure of the built environment, such as on the geometry and topology of it. To promote advancements on this front, we introduce the Nothing Stands Still (NSS) benchmark, which focuses on the spatiotemporal registration of 3D scenes undergoing large spatial and temporal change, ultimately creating one coherent spatiotemporal map. Specifically, the benchmark involves registering within the same coordinate system two or more partial 3D point clouds (fragments) originating from the same scene but captured from different spatiotemporal views. In addition to the standard task of pairwise registration, we assess multi-way registration of multiple fragments that belong to the same indoor environment and any temporal stage. As part of NSS, we introduce a dataset of 3D point clouds recurrently captured in large-scale building indoor environments that are under construction or renovation. The NSS benchmark presents three scenarios of increasing difficulty, with the goal to quantify the generalization ability of point cloud registration methods over space (within one building and across buildings) and time. We conduct extensive evaluations of state-of-the-art methods on NSS over all tasks and scenarios. The results demonstrate the necessity for novel methods specifically designed to handle large spatiotemporal changes. The homepage of our benchmark is at http://nothing-stands-still.com.
{"title":"Nothing Stands Still: A spatiotemporal benchmark on 3D point cloud registration under large geometric and temporal change","authors":"Tao Sun , Yan Hao , Shengyu Huang , Silvio Savarese , Konrad Schindler , Marc Pollefeys , Iro Armeni","doi":"10.1016/j.isprsjprs.2025.01.010","DOIUrl":"10.1016/j.isprsjprs.2025.01.010","url":null,"abstract":"<div><div>Building 3D geometric maps of man-made spaces is a well-established and active field that is fundamental to numerous computer vision and robotics applications. However, considering the continuously evolving nature of built environments, it is essential to question the capabilities of current mapping efforts in handling temporal changes. In addition to the above, the ability to create spatiotemporal maps holds significant potential for achieving sustainability and circularity goals. Existing mapping approaches focus on small changes, such as object relocation within common living spaces or self-driving car operation in outdoor spaces; all cases where the main structure of the scene remains fixed. Consequently, these approaches fail to address more radical change in the structure of the built environment, such as on the geometry and topology of it. To promote advancements on this front, we introduce the <strong><strong>Nothing Stands Still</strong> (<strong>NSS</strong>)</strong> benchmark, which focuses on the spatiotemporal registration of 3D scenes undergoing large spatial and temporal change, ultimately creating one coherent spatiotemporal map. Specifically, the benchmark involves registering within the same coordinate system two or more partial 3D point clouds (fragments) originating from the same scene but captured from different spatiotemporal views. In addition to the standard task of <em>pairwise</em> registration, we assess <em>multi-way</em> registration of multiple fragments that belong to the same indoor environment and any temporal stage. As part of <strong>NSS</strong>, we introduce a dataset of 3D point clouds recurrently captured in large-scale building indoor environments that are under construction or renovation. The <strong>NSS</strong> benchmark presents three scenarios of increasing difficulty, with the goal to quantify the generalization ability of point cloud registration methods over space (within one building and across buildings) and time. We conduct extensive evaluations of state-of-the-art methods on <strong>NSS</strong> over all tasks and scenarios. The results demonstrate the necessity for novel methods specifically designed to handle large spatiotemporal changes. The homepage of our benchmark is at <span><span>http://nothing-stands-still.com</span><svg><path></path></svg></span>.</div></div>","PeriodicalId":50269,"journal":{"name":"ISPRS Journal of Photogrammetry and Remote Sensing","volume":"220 ","pages":"Pages 799-823"},"PeriodicalIF":10.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143072521","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}
Pub Date : 2025-02-01DOI: 10.1016/j.isprsjprs.2025.01.021
Wei Wang , Stefan Brönnimann , Ji Zhou , Shaopeng Li , Ziwei Wang
Near-surface air temperature (NSAT) data is essential for climate analysis and applied research in areas with sparse ground-based observations. In recent years, machine learning (ML) techniques have been increasingly used to estimate NSAT, delivering promising results. However, in regions with limited observational samples, machine learning-based NSAT estimations may encounter challenges, potentially resulting in reduced accuracy. Therefore, this study introduces a novel model – TranSAT. TranSAT utilizes a transfer learning (TL) framework, deep neural network (DNN) and U-shape convolutional network (U-Net) to enhance the accuracy of NSAT estimations in regions with sparse observational data. Considering the scarcity of observation stations in certain regions, the Tibetan Plateau within the China's landmass (CNTP) is selected as the study region. The majority of observational stations are concentrated in the eastern and southeastern parts of CNTP, with a significant lack of stations in the northern and western regions. The scarce observations in the CNTP affect NSAT estimation accuracy in recent studies, thus limiting practical applications. The estimated NSAT (i.e., TranSAT NSAT) by TranSAT is evaluated by measurements of 10 independent meteorological stations from the Meteorological network in China's cold region (MSC). Evaluation results indicate an average coefficient of determination (R2) of 0.92 and a root mean squared error (RMSE) of 2.29 °C. The TranSAT NSAT exhibits an overall decrease of at least 7 % on RMSE compared to existing NSAT datasets, with a more significant enhancement of over 40 % in regions with sparse ground observations. These results highlight the good and consistent performance of TranSAT NSAT, further confirming that the proposed TranSAT model effectively improves NSAT estimation in areas with limited observational data.
{"title":"Near-surface air temperature estimation for areas with sparse observations based on transfer learning","authors":"Wei Wang , Stefan Brönnimann , Ji Zhou , Shaopeng Li , Ziwei Wang","doi":"10.1016/j.isprsjprs.2025.01.021","DOIUrl":"10.1016/j.isprsjprs.2025.01.021","url":null,"abstract":"<div><div>Near-surface air temperature (NSAT) data is essential for climate analysis and applied research in areas with sparse ground-based observations. In recent years, machine learning (ML) techniques have been increasingly used to estimate NSAT, delivering promising results. However, in regions with limited observational samples, machine learning-based NSAT estimations may encounter challenges, potentially resulting in reduced accuracy. Therefore, this study introduces a novel model – TranSAT. TranSAT utilizes a transfer learning (TL) framework, deep neural network (DNN) and U-shape convolutional network (U-Net) to enhance the accuracy of NSAT estimations in regions with sparse observational data. Considering the scarcity of observation stations in certain regions, the Tibetan Plateau within the China's landmass (CNTP) is selected as the study region. The majority of observational stations are concentrated in the eastern and southeastern parts of CNTP, with a significant lack of stations in the northern and western regions. The scarce observations in the CNTP affect NSAT estimation accuracy in recent studies, thus limiting practical applications. The estimated NSAT (i.e., TranSAT NSAT) by TranSAT is evaluated by measurements of 10 independent meteorological stations from the Meteorological network in China's cold region (MSC). Evaluation results indicate an average coefficient of determination (<em>R</em><sup>2</sup>) of 0.92 and a root mean squared error (RMSE) of 2.29 °C. The TranSAT NSAT exhibits an overall decrease of at least 7 % on RMSE compared to existing NSAT datasets, with a more significant enhancement of over 40 % in regions with sparse ground observations. These results highlight the good and consistent performance of TranSAT NSAT, further confirming that the proposed TranSAT model effectively improves NSAT estimation in areas with limited observational data.</div></div>","PeriodicalId":50269,"journal":{"name":"ISPRS Journal of Photogrammetry and Remote Sensing","volume":"220 ","pages":"Pages 712-727"},"PeriodicalIF":10.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143035287","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}
Pub Date : 2025-02-01DOI: 10.1016/j.isprsjprs.2025.01.003
Hao Li , Fabian Deuser , Wenping Yin , Xuanshu Luo , Paul Walther , Gengchen Mai , Wei Huang , Martin Werner
Nature disasters play a key role in shaping human-urban infrastructure interactions. Effective and efficient response to natural disasters is essential for building resilience and sustainable urban environment. Two types of information are usually the most necessary and difficult to gather in disaster response. The first information is about the disaster damage perception, which shows how badly people think that urban infrastructure has been damaged. The second information is geolocation awareness, which means how people’s whereabouts are made available. In this paper, we proposed a novel disaster mapping framework, namely CVDisaster, aiming at simultaneously addressing geolocalization and damage perception estimation using cross-view Street-View Imagery (SVI) and Very High-Resolution satellite imagery. CVDisaster consists of two cross-view models, where CVDisaster-Geoloc refers to a cross-view geolocalization model based on a contrastive learning objective with a Siamese ConvNeXt image encoder and CVDisaster-Est is a cross-view classification model based on a Coupled Global Context Vision Transformer (CGCViT). Taking Hurricane IAN as a case study, we evaluate the CVDisaster framework by creating a novel cross-view dataset (CVIAN) and conducting extensive experiments. As a result, we show that CVDisaster can achieve highly competitive performance (over 80% for geolocalization and 75% for damage perception estimation) with even limited fine-tuning efforts, which largely motivates future cross-view models and applications within a broader GeoAI research community. The data and code are publicly available at: https://github.com/tum-bgd/CVDisaster.
{"title":"Cross-view geolocalization and disaster mapping with street-view and VHR satellite imagery: A case study of Hurricane IAN","authors":"Hao Li , Fabian Deuser , Wenping Yin , Xuanshu Luo , Paul Walther , Gengchen Mai , Wei Huang , Martin Werner","doi":"10.1016/j.isprsjprs.2025.01.003","DOIUrl":"10.1016/j.isprsjprs.2025.01.003","url":null,"abstract":"<div><div>Nature disasters play a key role in shaping human-urban infrastructure interactions. Effective and efficient response to natural disasters is essential for building resilience and sustainable urban environment. Two types of information are usually the most necessary and difficult to gather in disaster response. The first information is about the disaster damage perception, which shows how badly people think that urban infrastructure has been damaged. The second information is geolocation awareness, which means how people’s whereabouts are made available. In this paper, we proposed a novel disaster mapping framework, namely CVDisaster, aiming at simultaneously addressing geolocalization and damage perception estimation using cross-view Street-View Imagery (SVI) and Very High-Resolution satellite imagery. CVDisaster consists of two cross-view models, where CVDisaster-Geoloc refers to a cross-view geolocalization model based on a contrastive learning objective with a Siamese ConvNeXt image encoder and CVDisaster-Est is a cross-view classification model based on a Coupled Global Context Vision Transformer (CGCViT). Taking Hurricane IAN as a case study, we evaluate the CVDisaster framework by creating a novel cross-view dataset (CVIAN) and conducting extensive experiments. As a result, we show that CVDisaster can achieve highly competitive performance (over 80% for geolocalization and 75% for damage perception estimation) with even limited fine-tuning efforts, which largely motivates future cross-view models and applications within a broader GeoAI research community. The data and code are publicly available at: <span><span>https://github.com/tum-bgd/CVDisaster</span><svg><path></path></svg></span>.</div></div>","PeriodicalId":50269,"journal":{"name":"ISPRS Journal of Photogrammetry and Remote Sensing","volume":"220 ","pages":"Pages 841-854"},"PeriodicalIF":10.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143072522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.isprsjprs.2025.01.005
Zhengfei Yan , Chi Chen , Shaolong Wu , Zhiye Wang , Liuchun Li , Shangzhe Sun , Bisheng Yang , Jing Fu
In transmission lines, regular inspections are crucial for maintaining their safe operation. Automatic and accurate detection of power transmission facility components (power components) in inspection imagery is an effective way to monitor the status of electrical assets within the Right of Ways (RoWs). However, the multitude of small-scale objects (e.g. grading rings, vibration dampers) in inspection imagery poses enormous challenges. To address these challenges, we propose a coarse-to-fine object detector named RF-DET. It adopts a Refocus Framework to refine the detection accuracy of small objects within the Regions of Interest of the Power Components (P-RoIs) generated through explicit context. On the basis above, an Implicit Context Aggregation Attention Module (ICAM) is proposed. ICAM utilizes a multi-branch structure to capture and aggregate multi-directional positional and global information, enabling in-depth mining of the implicit context among small objects. To verify the performance of this detector, a benchmark dataset named DOPI-UAV is constructed, comprising 4,438 UAV oblique images and 54,591 instances, encompassing six common categories of power components and one category of defect. Experimental results show that RF-DET achieves mAP of 62.7%, 55.7%, 84.6%, and 52.8% on the DOPI-UAV, Tower, CPLID, and InsD datasets, respectively. Compared to the state-of-the-art method, such as YOLOv9, RF-DET attains significant performance improvements, with increases of 5.2% in mAP and 6.4% in mAP50, respectively. Especially, the APS shows an improvement of 8.3%. The datasets and codes are available at https://github.com/DCSI2022/RF-DET.
{"title":"RF-DET: Refocusing on the small-scale objects using aggregated context for accurate power transmitting components detection on UAV oblique imagery","authors":"Zhengfei Yan , Chi Chen , Shaolong Wu , Zhiye Wang , Liuchun Li , Shangzhe Sun , Bisheng Yang , Jing Fu","doi":"10.1016/j.isprsjprs.2025.01.005","DOIUrl":"10.1016/j.isprsjprs.2025.01.005","url":null,"abstract":"<div><div>In transmission lines, regular inspections are crucial for maintaining their safe operation. Automatic and accurate detection of power transmission facility components (power components) in inspection imagery is an effective way to monitor the status of electrical assets within the Right of Ways (RoWs). However, the multitude of small-scale objects (e.g. grading rings, vibration dampers) in inspection imagery poses enormous challenges. To address these challenges, we propose a coarse-to-fine object detector named RF-DET. It adopts a Refocus Framework to refine the detection accuracy of small objects within the Regions of Interest of the Power Components (P-RoIs) generated through explicit context. On the basis above, an Implicit Context Aggregation Attention Module (ICAM) is proposed. ICAM utilizes a multi-branch structure to capture and aggregate multi-directional positional and global information, enabling in-depth mining of the implicit context among small objects. To verify the performance of this detector, a benchmark dataset named DOPI-UAV is constructed, comprising 4,438 UAV oblique images and 54,591 instances, encompassing six common categories of power components and one category of defect. Experimental results show that RF-DET achieves mAP of 62.7%, 55.7%, 84.6%, and 52.8% on the DOPI-UAV, Tower, CPLID, and InsD datasets, respectively. Compared to the state-of-the-art method, such as YOLOv9, RF-DET attains significant performance improvements, with increases of 5.2% in mAP and 6.4% in mAP<sub>50</sub>, respectively. Especially, the AP<sub>S</sub> shows an improvement of 8.3%. The datasets and codes are available at <span><span>https://github.com/DCSI2022/RF-DET</span><svg><path></path></svg></span>.</div></div>","PeriodicalId":50269,"journal":{"name":"ISPRS Journal of Photogrammetry and Remote Sensing","volume":"220 ","pages":"Pages 692-711"},"PeriodicalIF":10.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143161509","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}
Pub Date : 2025-02-01DOI: 10.1016/j.isprsjprs.2024.12.013
Ying Liu , Hong’an Wu , Yonghong Zhang , Zhong Lu , Yonghui Kang , Jujie Wei
Phase unwrapping (PhU) is one of the most critical steps in synthetic aperture radar interferometry (InSAR) technology. However, the current phase unwrapping methods cannot completely avoid the PhU errors, particularly in complex environments with low coherence. Here, we show that the PhU errors can be corrected well with the time series interferograms. We propose a three-dimensional automatic detection and correction (3D-ADAC) method based on phase closure for time-series InSAR PhU errors to improve the quality of the interferograms, especially for the regions with the same errors in different interferograms which cancel each other out in phase closure. The 3D-ADAC algorithm was evaluated with 26 Sentinel-1 SAR images and 72 phase closure loops over the Tianjin region, China, and compared with the popular MintPy and CorPhU methods. Our results demonstrate that the number of new arcs with model coherence coefficient greater than 0.7 achieved by the proposed method is 2.36 times that by the method used in the MintPy software and 3.07 times that by the CorPhU method. The corrected and improved interferograms will be helpful for accurately mapping the ground deformations or Earth topographies via InSAR technology. Codes and data are available at https://github.com/Lylionaurora/code3d-ADCD.
{"title":"3D automatic detection and correction for phase unwrapping errors in time series SAR interferometry","authors":"Ying Liu , Hong’an Wu , Yonghong Zhang , Zhong Lu , Yonghui Kang , Jujie Wei","doi":"10.1016/j.isprsjprs.2024.12.013","DOIUrl":"10.1016/j.isprsjprs.2024.12.013","url":null,"abstract":"<div><div>Phase unwrapping (PhU) is one of the most critical steps in synthetic aperture radar interferometry (InSAR) technology. However, the current phase unwrapping methods cannot completely avoid the PhU errors, particularly in complex environments with low coherence. Here, we show that the PhU errors can be corrected well with the time series interferograms. We propose a three-dimensional automatic detection and correction (3D-ADAC) method based on phase closure for time-series InSAR PhU errors to improve the quality of the interferograms, especially for the regions with the same errors in different interferograms which cancel each other out in phase closure. The 3D-ADAC algorithm was evaluated with 26 Sentinel-1 SAR images and 72 phase closure loops over the Tianjin region, China, and compared with the popular MintPy and CorPhU methods. Our results demonstrate that the number of new arcs with model coherence coefficient greater than 0.7 achieved by the proposed method is 2.36 times that by the method used in the MintPy software and 3.07 times that by the CorPhU method. The corrected and improved interferograms will be helpful for accurately mapping the ground deformations or Earth topographies via InSAR technology. Codes and data are available at https://github.com/Lylionaurora/code3d-ADCD.</div></div>","PeriodicalId":50269,"journal":{"name":"ISPRS Journal of Photogrammetry and Remote Sensing","volume":"220 ","pages":"Pages 232-245"},"PeriodicalIF":10.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142874572","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}
Pub Date : 2025-02-01DOI: 10.1016/j.isprsjprs.2024.12.023
Huiqun Ren , Xin Huang , Jie Yang , Guoqing Zhou
Timely and accurate monitoring of impervious surface areas (ISA) is crucial for effective urban planning and sustainable development. Recent advances in remote sensing technologies have enabled global ISA mapping at fine spatial resolution (<30 m) over long time spans (>30 years), offering the opportunity to track global ISA dynamics. However, existing 30 m global long-term ISA datasets suffer from omission and commission issues, affecting their accuracy in practical applications. To address these challenges, we proposed a novel global long-term ISA mapping method and generated a new 30 m global ISA dataset from 1985 to 2021, namely GISA-new. Specifically, to reduce ISA omissions, a multi-temporal Continuous Change Detection and Classification (CCDC) algorithm that accounts for newly added ISA regions (NA-CCDC) was proposed to enhance the diversity and representativeness of the training samples. Meanwhile, a multi-scale iterative (MIA) method was proposed to automatically remove global commissions of various sizes and types. Finally, we collected two independent test datasets with over 100,000 test samples globally for accuracy assessment. Results showed that GISA-new outperformed other existing global ISA datasets, such as GISA, WSF-evo, GAIA, and GAUD, achieving the highest overall accuracy (93.12 %), the lowest omission errors (10.50 %), and the lowest commission errors (3.52 %). Furthermore, the spatial distribution of global ISA omissions and commissions was analyzed, revealing more mapping uncertainties in the Northern Hemisphere. In general, the proposed method in this study effectively addressed global ISA omissions and removed commissions at different scales. The generated high-quality GISA-new can serve as a fundamental parameter for a more comprehensive understanding of global urbanization.
{"title":"Improving 30-meter global impervious surface area (GISA) mapping: New method and dataset","authors":"Huiqun Ren , Xin Huang , Jie Yang , Guoqing Zhou","doi":"10.1016/j.isprsjprs.2024.12.023","DOIUrl":"10.1016/j.isprsjprs.2024.12.023","url":null,"abstract":"<div><div>Timely and accurate monitoring of impervious surface areas (ISA) is crucial for effective urban planning and sustainable development. Recent advances in remote sensing technologies have enabled global ISA mapping at fine spatial resolution (<30 m) over long time spans (>30 years), offering the opportunity to track global ISA dynamics. However, existing 30 m global long-term ISA datasets suffer from omission and commission issues, affecting their accuracy in practical applications. To address these challenges, we proposed a novel global long-term ISA mapping method and generated a new 30 m global ISA dataset from 1985 to 2021, namely GISA-new. Specifically, to reduce ISA omissions, a multi-temporal Continuous Change Detection and Classification (CCDC) algorithm that accounts for newly added ISA regions (NA-CCDC) was proposed to enhance the diversity and representativeness of the training samples. Meanwhile, a multi-scale iterative (MIA) method was proposed to automatically remove global commissions of various sizes and types. Finally, we collected two independent test datasets with over 100,000 test samples globally for accuracy assessment. Results showed that GISA-new outperformed other existing global ISA datasets, such as GISA, WSF-evo, GAIA, and GAUD, achieving the highest overall accuracy (93.12 %), the lowest omission errors (10.50 %), and the lowest commission errors (3.52 %). Furthermore, the spatial distribution of global ISA omissions and commissions was analyzed, revealing more mapping uncertainties in the Northern Hemisphere. In general, the proposed method in this study effectively addressed global ISA omissions and removed commissions at different scales. The generated high-quality GISA-new can serve as a fundamental parameter for a more comprehensive understanding of global urbanization.</div></div>","PeriodicalId":50269,"journal":{"name":"ISPRS Journal of Photogrammetry and Remote Sensing","volume":"220 ","pages":"Pages 354-376"},"PeriodicalIF":10.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142925284","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}
Pub Date : 2025-02-01DOI: 10.1016/j.isprsjprs.2025.01.002
Chongyang Wang , Chenghu Zhou , Xia Zhou , Mingjie Duan , Yingwei Yan , Jiaxue Wang , Li Wang , Kai Jia , Yishan Sun , Danni Wang , Yangxiaoyue Liu , Dan Li , Jinyue Chen , Hao Jiang , Shuisen Chen
The study of estuarine turbidity maximum (ETM) has a long history. However, the algorithms and criteria for ETM identification vary significantly across estuaries and hydrological regimes. Moreover, almost all of these methods depend on derived water parameters, such as suspended sediment concentration and turbidity, which inevitably result in inherent errors in the ETM results. To overcome these disadvantages and develop a standard ETM recognition method that has good applicability in most estuaries, this study analyzed the spectral characteristics of 23 big river estuaries worldwide using Landsat and Sentinel sensor images. Based on the difference in band reflectance between the ETM and normal water bodies, we first proposed a universal method, defined as the product of the ratio of blue, green and red bands to their average value over the entire estuary, namely, Red Green Blue Turbidity (RGBT). Combined with the corresponding remote sensing images, the ETM distributions in the 23 estuaries were extracted and analyzed. It was found that the ETM recognition results for the Pearl River Estuary on different dates (2004, 2015) were consistent with those of previous studies. The validation accuracies (Q) reached 0.8335 and 0.8800, respectively, illustrating the effectiveness of the RGBT method in the Pearl River Estuary. For the other 22 estuaries, the RGBT-based ETM recognition results were evaluated using the corresponding visual interpretation. Comparisons and details of the ETM boundaries indicate that the method works well for all types of estuaries. It also included accurately identifying slightly turbid plumes from maritime wind turbines and bridge piers. The validation accuracy exceeded 0.9 (0.9025–0.9733) in seven estuaries, and surpassed 0.7898 in the remaining 15 estuaries. The RGBT method generally achieved higher accuracy for estuaries in Asia and Europe, followed by estuaries in America and Oceania, with a relatively lower accuracy for estuaries in Africa. But the variation in the accuracy in different regions was small. The average validation accuracy of all estuaries and different seasons was as high as 0.9027. This demonstrates that the unified method with same criterion can directly and effectively recognize ETM distributions from multi-source remote sensing data in different estuaries worldwide.
{"title":"A universal method to recognize global big rivers estuarine turbidity maximum from remote sensing","authors":"Chongyang Wang , Chenghu Zhou , Xia Zhou , Mingjie Duan , Yingwei Yan , Jiaxue Wang , Li Wang , Kai Jia , Yishan Sun , Danni Wang , Yangxiaoyue Liu , Dan Li , Jinyue Chen , Hao Jiang , Shuisen Chen","doi":"10.1016/j.isprsjprs.2025.01.002","DOIUrl":"10.1016/j.isprsjprs.2025.01.002","url":null,"abstract":"<div><div>The study of estuarine turbidity maximum (ETM) has a long history. However, the algorithms and criteria for ETM identification vary significantly across estuaries and hydrological regimes. Moreover, almost all of these methods depend on derived water parameters, such as suspended sediment concentration and turbidity, which inevitably result in inherent errors in the ETM results. To overcome these disadvantages and develop a standard ETM recognition method that has good applicability in most estuaries, this study analyzed the spectral characteristics of 23 big river estuaries worldwide using Landsat and Sentinel sensor images. Based on the difference in band reflectance between the ETM and normal water bodies, we first proposed a universal method, defined as the product of the ratio of blue, green and red bands to their average value over the entire estuary, namely, Red Green Blue Turbidity (RGBT). Combined with the corresponding remote sensing images, the ETM distributions in the 23 estuaries were extracted and analyzed. It was found that the ETM recognition results for the Pearl River Estuary on different dates (2004, 2015) were consistent with those of previous studies. The validation accuracies (Q) reached 0.8335 and 0.8800, respectively, illustrating the effectiveness of the RGBT method in the Pearl River Estuary. For the other 22 estuaries, the RGBT-based ETM recognition results were evaluated using the corresponding visual interpretation. Comparisons and details of the ETM boundaries indicate that the method works well for all types of estuaries. It also included accurately identifying slightly turbid plumes from maritime wind turbines and bridge piers. The validation accuracy exceeded 0.9 (0.9025–0.9733) in seven estuaries, and surpassed 0.7898 in the remaining 15 estuaries. The RGBT method generally achieved higher accuracy for estuaries in Asia and Europe, followed by estuaries in America and Oceania, with a relatively lower accuracy for estuaries in Africa. But the variation in the accuracy in different regions was small. The average validation accuracy of all estuaries and different seasons was as high as 0.9027. This demonstrates that the unified method with same criterion can directly and effectively recognize ETM distributions from multi-source remote sensing data in different estuaries worldwide.</div></div>","PeriodicalId":50269,"journal":{"name":"ISPRS Journal of Photogrammetry and Remote Sensing","volume":"220 ","pages":"Pages 509-523"},"PeriodicalIF":10.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142967835","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}
Pub Date : 2025-02-01DOI: 10.1016/j.isprsjprs.2025.01.009
Lina Yin , Mingjun Deng , Yin Yang , Yunqing Huang , Qili Tang
Synthetic aperture radar (SAR) image positioning technology is extensively used in many scientific fields, including land surveying and mapping. Geometric self-calibration can be performed if images are captured in three directions. However, when the number of images is too small, self-calibration of the SAR images based on the range-Doppler (RD) model appears to be inaccurate. Hence, a robust geometric calibration method has an important impact on calibration results. The effectiveness of such a method depends on the validity of the SAR images. This implies that the calibration can algorithmically optimize the images involved in self-calibration such that the calibration results are close to the true unknown parameters. To overcome these inaccuracies in geometric calibration, this study proposes a flexible calibration approach. The determinant and accuracy stabilization factor (ASF) are utilized to filter the images, allowing the evaluation of singular solutions and determining the validity of the SAR images. Experimental results demonstrate that the robustness of the proposed approach. In addition, the slant range equation is suggested as the dominant equation for analyzing image calibration error sources and image capture. It is found that satellite position is the main source of image calibration errors. Therefore, the impact of the satellite position and the associated incidence angle on the calibration is analyzed. The analysis reveals that it is desirable for satellites to capture ipsilateral images with incidence angles greater than 8. This finding justifies the acquisition of SAR images.
{"title":"A sensitive geometric self-calibration method and stability analysis for multiview spaceborne SAR images based on the range-Doppler model","authors":"Lina Yin , Mingjun Deng , Yin Yang , Yunqing Huang , Qili Tang","doi":"10.1016/j.isprsjprs.2025.01.009","DOIUrl":"10.1016/j.isprsjprs.2025.01.009","url":null,"abstract":"<div><div>Synthetic aperture radar (SAR) image positioning technology is extensively used in many scientific fields, including land surveying and mapping. Geometric self-calibration can be performed if images are captured in three directions. However, when the number of images is too small, self-calibration of the SAR images based on the range-Doppler (RD) model appears to be inaccurate. Hence, a robust geometric calibration method has an important impact on calibration results. The effectiveness of such a method depends on the validity of the SAR images. This implies that the calibration can algorithmically optimize the images involved in self-calibration such that the calibration results are close to the true unknown parameters. To overcome these inaccuracies in geometric calibration, this study proposes a flexible calibration approach. The determinant and accuracy stabilization factor (ASF) are utilized to filter the images, allowing the evaluation of singular solutions and determining the validity of the SAR images. Experimental results demonstrate that the robustness of the proposed approach. In addition, the slant range equation is suggested as the dominant equation for analyzing image calibration error sources and image capture. It is found that satellite position is the main source of image calibration errors. Therefore, the impact of the satellite position and the associated incidence angle on the calibration is analyzed. The analysis reveals that it is desirable for satellites to capture ipsilateral images with incidence angles greater than 8<span><math><mo>°</mo></math></span>. This finding justifies the acquisition of SAR images.</div></div>","PeriodicalId":50269,"journal":{"name":"ISPRS Journal of Photogrammetry and Remote Sensing","volume":"220 ","pages":"Pages 550-562"},"PeriodicalIF":10.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142989649","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}
Pub Date : 2025-02-01DOI: 10.1016/j.isprsjprs.2024.12.017
Xin-Yi Tong , Runmin Dong , Xiao Xiang Zhu
Land cover information is indispensable for advancing the United Nations’ sustainable development goals, and land cover mapping under a more detailed category system would significantly contribute to economic livelihood tracking and environmental degradation measurement. However, the substantial difficulty in acquiring fine-grained training data makes the implementation of this task particularly challenging. Here, we propose to combine fully labeled source domain and weakly labeled target domain for weakly supervised domain adaptation (WSDA). This is beneficial as the utilization of sparse and coarse weak labels can considerably alleviate the labor required for precise and detailed land cover annotation. Specifically, we introduce the Prototype-based pseudo-label Rectification and Expansion (PRE) approach, which leverages the prototypes (i.e., the class-wise feature centroids) as the bridge to connect sparse labels and global feature distributions. According to the feature distances to the prototypes, the confidence of pseudo-labels predicted in the unlabeled regions of the target domain is assessed. This confidence is then utilized to guide the dynamic expansion and rectification of pseudo-labels. Based on PRE, we carry out high categorical resolution land cover mapping for 10 cities in different regions around the world, severally using PlanetScope, Gaofen-1, and Sentinel-2 satellite images. In the study areas, we achieve cross-sensor, cross-category, and cross-continent WSDA, with the overall accuracy exceeding 80%. The promising results indicate that PRE is capable of reducing the dependency of land cover classification on high-quality annotations, thereby improving label efficiency. We expect our work to enable global fine-grained land cover mapping, which in turn promote Earth observation to provide more precise and thorough information for environmental monitoring. Our data and code will be available publicly at https://zhu-xlab.github.io/PRE-land-cover.html.
{"title":"Global high categorical resolution land cover mapping via weak supervision","authors":"Xin-Yi Tong , Runmin Dong , Xiao Xiang Zhu","doi":"10.1016/j.isprsjprs.2024.12.017","DOIUrl":"10.1016/j.isprsjprs.2024.12.017","url":null,"abstract":"<div><div>Land cover information is indispensable for advancing the United Nations’ sustainable development goals, and land cover mapping under a more detailed category system would significantly contribute to economic livelihood tracking and environmental degradation measurement. However, the substantial difficulty in acquiring fine-grained training data makes the implementation of this task particularly challenging. Here, we propose to combine fully labeled source domain and weakly labeled target domain for weakly supervised domain adaptation (WSDA). This is beneficial as the utilization of sparse and coarse weak labels can considerably alleviate the labor required for precise and detailed land cover annotation. Specifically, we introduce the Prototype-based pseudo-label Rectification and Expansion (<em>PRE</em>) approach, which leverages the prototypes (i.e., the class-wise feature centroids) as the bridge to connect sparse labels and global feature distributions. According to the feature distances to the prototypes, the confidence of pseudo-labels predicted in the unlabeled regions of the target domain is assessed. This confidence is then utilized to guide the dynamic expansion and rectification of pseudo-labels. Based on PRE, we carry out high categorical resolution land cover mapping for 10 cities in different regions around the world, severally using PlanetScope, Gaofen-1, and Sentinel-2 satellite images. In the study areas, we achieve cross-sensor, cross-category, and cross-continent WSDA, with the overall accuracy exceeding 80%. The promising results indicate that PRE is capable of reducing the dependency of land cover classification on high-quality annotations, thereby improving label efficiency. We expect our work to enable global fine-grained land cover mapping, which in turn promote Earth observation to provide more precise and thorough information for environmental monitoring. Our data and code will be available publicly at <span><span>https://zhu-xlab.github.io/PRE-land-cover.html</span><svg><path></path></svg></span>.</div></div>","PeriodicalId":50269,"journal":{"name":"ISPRS Journal of Photogrammetry and Remote Sensing","volume":"220 ","pages":"Pages 535-549"},"PeriodicalIF":10.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142989650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}