Rui Li, Xiaodan Wang, Jian Wang, Yafei Song, Lei Lei
{"title":"SAR Target Recognition Based on Efficient Fully Convolutional Attention Block CNN","authors":"Rui Li, Xiaodan Wang, Jian Wang, Yafei Song, Lei Lei","doi":"10.1109/LGRS.2020.3037256","DOIUrl":"https://doi.org/10.1109/LGRS.2020.3037256","url":null,"abstract":"Attention mechanisms have recently shown strong potential in improving the performance of convolutional neural networks (CNNs). This letter proposes a fully convolutional attention block (FCAB) that can be combined with a CNN to refine important features and suppress unnecessary ones in synthetic aperture radar (SAR) images. The FCAB consists of a channel attention module and a spatial attention module. For the channel attention module, we use average-pooling and max-pooling to learn complementary features, and apply group convolution to aggregate the information of the two types of channels. Global average-pooling is then used to encode the channel-wise importance. For the spatial attention module, the average-pooling and max-pooling along the channel axis are used to generate two spatial feature maps, and then two very lightweight convolutional layers are used to encode the spatial weight map. Experimental results on SAR images demonstrate that our FCAB can focus on important channels and object regions. It uses relatively few parameters and is computationally efficient, while bringing about significant performance gain for SAR recognition.","PeriodicalId":13046,"journal":{"name":"IEEE Geoscience and Remote Sensing Letters","volume":"19 1","pages":"1-5"},"PeriodicalIF":4.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/LGRS.2020.3037256","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62474993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"CYGNSS Soil Moisture Estimations Based on Quality Control","authors":"F. Tang, Songhua Yan","doi":"10.1109/lgrs.2021.3119850","DOIUrl":"https://doi.org/10.1109/lgrs.2021.3119850","url":null,"abstract":"In this letter, we proposed a method based on cyclone global navigation satellite system (CYGNSS) for improving the accuracy of soil moisture (SM) estimation through the selection of auxiliary data and a four-step quality control. We investigate the impact of elevation and vegetation, as well as evaluating the quality of Doppler delay map (DDM) and different ground terrains. The program adopts the support vector machine (SVM) algorithm, input CYGNSS, and auxiliary data. With the hourly SM data on Wuhan Baoxie site from January 2020 to August 2020 as an example, the effectiveness of quality control was verified. A substantial improvement in correlation coefficient of ~0.46 for average between CYGNSS reflectivity and <italic>in situ</italic> SM was obtained compared with ~0.03 before quality control, resulting in better SM estimation accuracy compared with that of <italic>in situ</italic> measurements (from <inline-formula> <tex-math notation=\"LaTeX\">$R = 0.67$ </tex-math></inline-formula> to 0.87).","PeriodicalId":13046,"journal":{"name":"IEEE Geoscience and Remote Sensing Letters","volume":"19 1","pages":"1-5"},"PeriodicalIF":4.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62482543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Ship Detection Method Based on Scattering Contribution for PolSAR Image","authors":"Xueli Pan, Zhenhua Wu, Lixia Yang, Zhixiang Huang","doi":"10.1109/lgrs.2021.3138796","DOIUrl":"https://doi.org/10.1109/lgrs.2021.3138796","url":null,"abstract":"Due to the differentiation of polarimetric scattering mechanisms between ships and sea surface, designing the ship detection method in polarimetric synthetic aperture radar (PolSAR) is a potential promising technique and has been paid extensive attention. The complexity of sea clutter and weak scattering of small ships result in a great challenge for high-precision ship detection. In this letter, we investigate the scattering mechanisms of ships to improve the detection performance and propose a novel ship detection method based on the principal contribution of scattering mechanisms. First, the seven-component model-based decomposition (SCMD) is used to analyze the scattering mechanisms of ships. Second, the primary scattering contribution and local contrast (SCLC) mechanism are used to enhance ships, especially small ships. Finally, the threshold segmentation is used to realize the extraction of ships. Experimental results by real PolSAR data not only verify the rationality and effectiveness of the constructed detection metric but also show the clear superiority of the proposed detection method, which can encourage further application of polarimetric scattering mechanisms in ship detection.","PeriodicalId":13046,"journal":{"name":"IEEE Geoscience and Remote Sensing Letters","volume":"19 1","pages":"1-5"},"PeriodicalIF":4.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62485860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Meta Self-Supervised Learning for Distribution Shifted Few-Shot Scene Classification","authors":"Tengfei Gong, Xiangtao Zheng, Xiaoqiang Lu","doi":"10.1109/lgrs.2022.3174277","DOIUrl":"https://doi.org/10.1109/lgrs.2022.3174277","url":null,"abstract":"Few-shot classification tries to recognize novel remote sensing image categories with a few shot samples. However, current methods assume that the test dataset shares the same domain with the labeled training dataset where prior knowledge is learned. It is infeasible to collect a training dataset for each domain, since remote sensing images may come from various domains. Exploiting the existing labeled dataset from another domain (source domain) to help the target dataset (target domain) classification would be efficient. In this letter, both meta-learning and self-supervised learning are jointly conducted for few-shot classification. Specifically, meta-learning is executed over a pretrained network for few-shot classification. Furthermore, self-supervised learning is exploited to fit the target domain distribution by training on unlabeled target domain images. Experiments are conducted on NWPU, EuroSAT and Merced datasets to validate the effectiveness.","PeriodicalId":13046,"journal":{"name":"IEEE Geoscience and Remote Sensing Letters","volume":"19 1","pages":"1-5"},"PeriodicalIF":4.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62490567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Multiscale Context Aggregation Network for Building Change Detection Using High Resolution Remote Sensing Images","authors":"J. Dong, Wufan Zhao, Shuai Wang","doi":"10.1109/LGRS.2021.3121094","DOIUrl":"https://doi.org/10.1109/LGRS.2021.3121094","url":null,"abstract":"The existing methods of building change detection (CD) using remote sensing (RS) images are still deficient in handling scale variation and class imbalance problems, indicating a decrease in the robustness of small-object detection and pseudo-change information. Thus, a novel building CD framework called the multiscale context aggregation network (MSCANet) is proposed. The high-resolution network is integrated into the feature extracting stage to maintain high-resolution representations throughout the whole process. Then, multiscale context information is aggregated using a scale-aware feature pyramid module (FPM). Recognition performance can be improved from discriminant feature representation learning by using a channel–spatial attention module. Furthermore, a class-balanced loss is proposed to reduce the impact of class imbalance in long-tail datasets. Experimental results from using the LEVIR-CD and SZTAKI AirChange benchmark datasets prove the superiority of the MSCANet over the other baseline methods, with improved maximum F1 scores of 5.28 and 8.47, respectively.","PeriodicalId":13046,"journal":{"name":"IEEE Geoscience and Remote Sensing Letters","volume":"19 1","pages":"1-5"},"PeriodicalIF":4.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62482892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yi Kong, Xuesong Wang, Yuhu Cheng, Yangchi Chen, C. L. P. Chen
{"title":"Graph Domain Adversarial Network With Dual-Weighted Pseudo-Label Loss for Hyperspectral Image Classification","authors":"Yi Kong, Xuesong Wang, Yuhu Cheng, Yangchi Chen, C. L. P. Chen","doi":"10.1109/lgrs.2021.3135310","DOIUrl":"https://doi.org/10.1109/lgrs.2021.3135310","url":null,"abstract":"A hyperspectral image (HSI) classification method named graph domain adversarial network with dual-weighted pseudo-label loss (GDAN-DWPL) is proposed in this letter. First, in order to extract more discriminative features, GDAN is applied to the transfer task of HSI. Then, a more reliable spectral–spatial graph is constructed by comprehensively utilizing the abundant spectral features and spatial contextual information. Finally, due to the misalignment of probability distribution on class-level caused by inaccurate pseudo-labels of target domain, a dual-weighted pseudo-label loss is proposed from the perspective of spatiality and confidence. By assigning larger weights to more reliable pixels and eliminating pixels with false pseudo-labels, the negative impact on learning process of prediction model can be reduced. Experimental results on four real HSI datasets show the superiority of GDAN-DWPL.","PeriodicalId":13046,"journal":{"name":"IEEE Geoscience and Remote Sensing Letters","volume":"19 1","pages":"1-5"},"PeriodicalIF":4.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62485540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hafize Hasar, U. Hasar, Y. Kaya, T. Oztas, M. Y. Canbolat, Nevzat Aslan, M. Ertugrul, O. Ramahi
{"title":"Broadband Soil Permittivity Measurements Using a Novel De-Embedding Line–Line Method","authors":"Hafize Hasar, U. Hasar, Y. Kaya, T. Oztas, M. Y. Canbolat, Nevzat Aslan, M. Ertugrul, O. Ramahi","doi":"10.1109/lgrs.2021.3140097","DOIUrl":"https://doi.org/10.1109/lgrs.2021.3140097","url":null,"abstract":"A new de-embedding line–line method has been proposed for accurate complex relative permittivity (<inline-formula> <tex-math notation=\"LaTeX\">$varepsilon _{r}$ </tex-math></inline-formula>) determination of soil samples loaded into an EIA 1-5/8” coaxial transmission line measurement system. The method has three main features. First, it bypasses the requirement of calibration of this system by using only two identical coaxial lines with different lengths. Second, it does not need any numerical technique for <inline-formula> <tex-math notation=\"LaTeX\">$varepsilon _{r}$ </tex-math></inline-formula> determination. Third, it does not require knowledge of electromagnetic properties and thickness information of the bead used for supporting soil samples. The method is next validated by simulations performed using a full 3-D electromagnetic simulation program (CST Microwave Studio) and by <inline-formula> <tex-math notation=\"LaTeX\">$varepsilon _{r}$ </tex-math></inline-formula> measurement of a polyethylene (PE) material. Finally, <inline-formula> <tex-math notation=\"LaTeX\">$varepsilon _{r}$ </tex-math></inline-formula> values of three air-dried and water-saturated soil samples having 90% or more sand content with different electrical conductivities (ECs) and gathered from different areas of the city Gaziantep in Turkey, were measured.","PeriodicalId":13046,"journal":{"name":"IEEE Geoscience and Remote Sensing Letters","volume":"19 1","pages":"1-5"},"PeriodicalIF":4.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62486020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 Refocusing for Defocused ISAR Images by Complex-Valued Pix2pixHD Network","authors":"Haoxuan Yuan, Hongbo Li, Yun Zhang, Yong Wang, Zitao Liu, Chenxi Wei, Chengxin Yao","doi":"10.1109/LGRS.2022.3210036","DOIUrl":"https://doi.org/10.1109/LGRS.2022.3210036","url":null,"abstract":"Inverse synthetic aperture radar (ISAR) is an effective detection method for targets. However, for the maneuvering targets, the Doppler frequency induced by an arbitrary scatterer on the target is time-varying, which will cause defocus on ISAR images and bring difficulties for the further recognition process. It is hard for traditional methods to well refocus all positions on the target well. In recent years, generative adversarial networks (GANs) achieve great success in image translation. However, the current refocusing models ignore the information of high-order terms containing in the relationship between real and imaginary parts of the data. To this end, an end-to-end refocusing network, named complex-valued pix2pixHD (CVPHD), is proposed to learn the mapping from defocus to focus, which utilizes complex-valued (CV) ISAR images as an input. A CV instance normalization layer is applied to mine the deep relationship between the complex parts by calculating the covariance of them and accelerate the training. Subsequently, an innovative adaptively weighted loss function is put forward to improve the overall refocusing effect. Finally, the proposed CVPHD is tested with the simulated and real dataset, and both can get well-refocused results. The results of comparative experiments show that the refocusing error can be reduced if extending the pix2pixHD network to the CV domain and the performance of CVPHD surpasses other autofocus methods in refocusing effects. The code and dataset have been available online (https://github.com/yhx-hit/CVPHD).","PeriodicalId":13046,"journal":{"name":"IEEE Geoscience and Remote Sensing Letters","volume":"19 1","pages":"1-5"},"PeriodicalIF":4.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62496447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Research on Shallow Groundwater Enrichment Assessment Based on RS and GIS Arid and Semi-Arid Areas","authors":"Chuanyue Yang","doi":"10.23977/geors.2022.050106","DOIUrl":"https://doi.org/10.23977/geors.2022.050106","url":null,"abstract":": The area of arid and semi-arid areas in the world is increasing; in order to solve the issues related to the shallow groundwater enrichment assessment of the arid semi-arid areas, take the typical arid and semi-arid area as the research area of Wuwei Citizen Qin County, Gansu, through remote sensing, GF-6, CBERS04 and DEM are used as data sources to use layer analysis to build an evaluation model for hierarchical enrichment results. It has obtained the laws of shallow groundwater distribution in the research zone in the past five years and the next five years. The trend of water level distribution in the past five years is generally consistent, showing from the southwest to the northeast gradually decreases, there are multiple groundwater funnels, and the shallow groundwater content will remain stable and will increase slightly in the next five years. The results of this study evaluate the development trend of shallow groundwater in Wuwei citizens in Gansu; it provides a scientific basis for future shallow groundwater management.","PeriodicalId":13046,"journal":{"name":"IEEE Geoscience and Remote Sensing Letters","volume":"29 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75838844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}