Advances in Space Research最新文献

{"title":"A multiscale and cross-level feature fusion method for remote sensing image target detection","authors":"Shan Wenchao,&nbsp;Yang Shuwen,&nbsp;Li Yikun,&nbsp;Kou Ruixiong","doi":"10.1016/j.asr.2025.03.044","DOIUrl":"10.1016/j.asr.2025.03.044","url":null,"abstract":"<div><div>Multiscale feature extraction and multilevel feature fusion are essential in the multiscale target detection of remote sensing images under complex backgrounds. However, mainstream feature extraction networks exhibit limited adaptability in their receptive fields and cannot accurately detect small targets with sparse features and large targets with blurred boundaries. Additionally, the feature fusion networks cannot effectively assess the importance of feature maps when integrating different depths of feature maps, resulting in an inaccurate representation of target area features. For this reason, we proposes a multiscale and cross-level feature fusion method for remote sensing image target detection. First, we construct a Multiscale Feature Extraction Network (MSFENet) to achieve comprehensive extraction of multiscale target features. We design a Scale-Adaptive Feature Extractor (SAFE) that encourages the model to realize multilevel synergistic cooperation within the sensing field, enabling accurate capture and efficient utilization of target feature information across different scales, thereby significantly enhancing the network’s capability to extract multiscale features. Additionally, in the deeper layers of the extraction network, we introduce a Cascading Context-Aware Module (CCAM) to enhance further the network’s ability to acquire deeper semantic richness while mitigating interference from background information. To fully exploit the latent information in feature maps at all levels of the backbone network, this study proposes a novel Cross-Level Feature Fusion Network (CLFFNet). This network incorporates a Sparse Feature Extraction Block (SFEB) to improve feature extraction quality. Through a carefully designed feature-adaptive cross-level interaction mechanism, the SFEB dynamically integrates the rich and critical detailed information with deep semantic information of the backbone network, significantly enhancing the integrity and discriminability of target feature information. The proposed module effectively improves the detection performance of small targets. The experimental results confirm the effectiveness and generalizability of the proposed method. Compared to existing target detection models, the proposed method achieves mAP values of 77.6 % and 90.1 % on the DIOR and HRRSD datasets, significantly outperforming the competitive models.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"75 11","pages":"Pages 7944-7959"},"PeriodicalIF":2.8,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143936026","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":"A statistical evaluation of Sentinel 2 and Landsat 9 sensors in water quality retrieval in mesotrophic and hypereutrophic reservoirs of India","authors":"Eswarvikram E,&nbsp;Abdul Wahid A,&nbsp;Arunbabu E,&nbsp;Akshaya Prabha A V,&nbsp;Gilbert Johnson P","doi":"10.1016/j.asr.2025.03.042","DOIUrl":"10.1016/j.asr.2025.03.042","url":null,"abstract":"<div><div>The present study compares the performance of Sentinel 2 and Landsat 9 sensors in estimating water quality parameters in two reservoirs in India that have contrasting trophic statuses. In-situ measurements and reflections captured by the two sensors were regressed to derive the concentrations of Chlorophyll-<em>a</em>, electrical conductivity, and total dissolved solids from the satellite images. Analysed the spatial and temporal variations of these parameters and the trophic state index of the reservoirs. The study reports that Bhavani Sagar Reservoir (BSR) is mesotrophic and has lower nutrient levels than the Krishnagiri Reservoir Project (KRP), which is hypereutrophic and has higher algal blooms. Sentinel 2 outperforms Landsat 9 in the study for parameters such as Chlorophyll-<em>a</em>, which shows higher spatial variability of SD = 58.95 % in the BSR reservoir (R² = 0.71 for Sentinel 2 and R² = 0.61 for Landsat 9). For parameters like EC and TDS, Landsat 9 matches the performance of Sentinel in both KRP and BSR as their variability doesn’t change much. The study also finds the use of different spectral resolutions particularly red edge bands towards improving the accuracy of the models. From the study, it is evident that Sentinel 2’s better spatial and spectral resolution facilitates the monitoring of water quality indicators with a wider spatial distribution, whereas Landsat 9’s performance is best suited for small reservoirs with less regional fluctuation in water quality.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"75 11","pages":"Pages 7932-7943"},"PeriodicalIF":2.8,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143936024","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":"Secure Satellite Image Transmission with Dynamic Encipherment and AuthKeX Protocol","authors":"Eldo P. Elias,&nbsp;A. Santhanavijayan","doi":"10.1016/j.asr.2025.03.040","DOIUrl":"10.1016/j.asr.2025.03.040","url":null,"abstract":"<div><div>A dynamic image encipherment system, along with an authentication and key exchange protocol (AuthKeX), is proposed for securing images communicated between satellites and base stations. The symmetric encipherment system utilizes dynamic substitution boxes (S-box) and permutation boxes (P-box). The dynamic P-boxes are meticulously crafted using the Fisher–Yates shuffling method, strengthened by the JoanS-MuraliP (JSMP) map. The JSMP map, renowned for its one-dimensional discrete nonlinear characteristics and extensive chaotic regime, enhances the cryptographic strength of this approach.</div><div>The AuthKeX protocol facilitates the secure distribution of symmetric keys essential for the encipherment system while also providing robust authentication and non-repudiation services. This protocol is grounded in the principles of Elliptic Curve Cryptography, ensuring a high level of security.</div><div>Rigorous security testing on the encipherment system has demonstrated its resilience against various statistical and differential attacks. Notably, the system exhibited a flawless 100 % Non-Linear Pixel Change Rate (NPCR), outperforming existing state-of-the-art methods. Additionally, the proposed AuthKeX protocol is impervious to man-in-the-middle attacks, ensuring the integrity of communication channels. This comprehensive approach marks a significant advancement in image confidentiality and trustworthy communication within satellite environments.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"75 11","pages":"Pages 8319-8333"},"PeriodicalIF":2.8,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143936540","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":"Acceleration-level coordinated control of a dual-arm free-floating space robot under hard joint constraints","authors":"Zhihui Xue ,&nbsp;Jinguo Liu ,&nbsp;Xin Zhang ,&nbsp;Hao Zhou ,&nbsp;Yangmin Li","doi":"10.1016/j.asr.2025.03.043","DOIUrl":"10.1016/j.asr.2025.03.043","url":null,"abstract":"<div><div>Dual-arm space robots are becoming increasingly crucial in on-orbit servicing missions. The online motion control of a dual-arm redundant space robot with hard joint constraints presents significant challenges due to its free-floating base. In this article, we proposed an acceleration-level coordinated control framework to solve hard joint constraints and dynamic singularity. The proposed framework combines a task scheduling strategy to achieve saturation in the null space, so that different tasks can achieve trajectory tracking with minimal task scaling under given joint hard constraints. The framework can achieve efficient online control by sequentially abandoning the use of joints that exceed the joint constraint and reintroducing these commands at their saturation level by projecting them into the appropriate null space. Finally, we verify the tracking performance of the algorithm through numerical simulation and experimental research. By comparing the proposed algorithm with the quadratic programming and pseudo-inverse methods, the algorithm has shown excellent online motion control performance, with a computation time of approximately 1 ms within a single sampling period.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"75 11","pages":"Pages 8122-8139"},"PeriodicalIF":2.8,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143936107","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":"Multi-step probabilistic forecasting for sunspot numbers based on LightGBM","authors":"B. Niu,&nbsp;Z. Huang","doi":"10.1016/j.asr.2025.03.041","DOIUrl":"10.1016/j.asr.2025.03.041","url":null,"abstract":"<div><div>As a comprehensive indicator of solar activity encompassing the entire visible disk, sunspot number (SSN) plays a pivotal role in both space weather forecasting and anomaly event monitoring. In this study, we propose a straightforward yet effective probabilistic model based on light gradient boosting machine (LightGBM) for multi-step ahead prediction of sunspot numbers. To achieve this, by leveraging the seasonal-trend decomposition using locally estimated scatterplot smoothing (Loess) method known as STL, we decompose the trend, seasonal variations, and residual components from the time series of sunspots, and these components are used as input features. The stepwise optimization algorithm in Optuna is employed to fine-tune the model’s hyperparameters. We conduct a comprehensive performance analysis of the proposed model using the SSN dataset, covering the period of 1755/02-2024/10. Our experimental results demonstrate that the proposed model outperforms existing methods by reducing errors. Furthermore, through quantitative uncertainty and probabilistic analysis, we establish the reliability of prediction intervals in most cases, enabling effective anomaly detection during anomalous events.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"75 11","pages":"Pages 8398-8410"},"PeriodicalIF":2.8,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143934922","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":"Precise baseline determination for the four-satellite InSAR constellation HT-01 with ambiguity resolution constraints","authors":"Dachen Peng ,&nbsp;Shibo Guo ,&nbsp;Defeng Gu ,&nbsp;Kai Shao ,&nbsp;Houzhe Zhang ,&nbsp;Ruiyun Yang ,&nbsp;Jufeng Lu ,&nbsp;Jiangkai Liu ,&nbsp;Haoseng Wang ,&nbsp;LiuPeng Huang","doi":"10.1016/j.asr.2025.03.039","DOIUrl":"10.1016/j.asr.2025.03.039","url":null,"abstract":"<div><div>Distributed interferometric SAR (InSAR) systems is evolving from dual-satellite configurations to multi-satellite systems. The Hongtu-01 constellation (HT-01), world’s first four-satellite interferometric SAR system utilizing a cartwheel formation, marks a significant milestone in China. Precision orbit determination (POD) and precision baseline determination (PBD) are essential for the successful execution of the HT-01 mission. However, baseline determination poses a challenge to differential GPS techniques due to the requirement for simultaneous determination of multiple baselines efficiently. As an alternative, absolute orbit can be computed individually for each spacecraft and used for the generation of precise baseline products. In addition, single-receiver ambiguity resolution (SR-AR) and double-differential ambiguity resolution (DD-AR) could be employed as constraint to enhance the accuracy of POD. In this paper, the performance of orbit and baseline determination for HT-01 is comprehensively evaluated. For further improving POD precision, receiver GPS signal phase center variations (PCV) models with 3 × 3°grid map and maneuver handling was employed. Among POD solutions, the results for the SLR residuals are 2.12 cm, 1.94 cm, 1.59 cm and 1.53 cm corresponding to the ambiguity-float, ambiguity-float + PCV, ambiguity-fixed and ambiguity-fixed + PCV orbit solution, respectively. Furthermore, we analyze the baseline difference between the baseline solution of SR-AR with approximately 92 % ambiguity fixing rates and baseline solution of DD-AR with almost 100 % ambiguity fixing rates. Result exhibit baseline consistency of approximately 1∼2 mm on each direction. Besides, baseline overlapping with 3D RMS consistency shows 1.07 mm and 1.23 mm for DD-AR and SR-AR, respectively. The above solutions can be considered as an effective approach for prospective formation-flying remote sensing missions with multi-baseline determination for a multi-satellite constellation.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"75 11","pages":"Pages 7917-7931"},"PeriodicalIF":2.8,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143936023","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":"Pose acquisition of non-cooperative spacecraft by point cloud template matching","authors":"Jiaqi Feng ,&nbsp;Zhang Zhang ,&nbsp;Zhongguang Yang ,&nbsp;Jinpei Yu ,&nbsp;Wen Chen ,&nbsp;Liang Chang ,&nbsp;Hongyu Chen","doi":"10.1016/j.asr.2025.03.035","DOIUrl":"10.1016/j.asr.2025.03.035","url":null,"abstract":"<div><div>This paper presents an initial pose acquisition method for non-cooperative spacecraft based on point cloud template matching. Utilizing the three-dimensional point clouds as input data, the proposed method matches the measured point cloud with an offline-generated template database to determine the coarse pose. The novelty of this study lies in the introduction of an offline template database with only one degree of freedom, resulting in a substantial reduction in both onboard storage and computational requirements. Additionally, position estimation, based on the sensor’s optical axis and target orientation bounding box features, improves ICP algorithm convergence to the global optimum compared to the traditional centroiding approach. Finally, a symmetry transformation strategy is proposed to address the pose ambiguity caused by axial symmetry. Comprehensive numerical simulations validate the effectiveness of the proposed method on sparse and uneven datasets, as well as on targets with varying shapes. Further validation using spaceborne data demonstrates the feasibility of the algorithm in practical space applications.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"75 10","pages":"Pages 7242-7258"},"PeriodicalIF":2.8,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143907544","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":"Aquifer restoration in the Lubei Plain, China: Insights from InSAR and groundwater head monitoring","authors":"Guangli Su ,&nbsp;Chunbao Xiong ,&nbsp;Wei Zhan ,&nbsp;Xuechuan Li ,&nbsp;Hong Liang ,&nbsp;Yu Li","doi":"10.1016/j.asr.2025.03.033","DOIUrl":"10.1016/j.asr.2025.03.033","url":null,"abstract":"<div><div>Although groundwater levels (GWL) have gradually stabilized and even increased in some regions under human intervention, persistent land subsidence remains a concern. This situation underscores the urgent need to investigate the restoration mechanisms of the aquifer system, particularly focusing on the interconnected processes of groundwater dynamics and strata deformation. This study specifically concentrates on the Lubei Plain in the southeast of the North China Plain—a chief recipient area of the East Route of the South-to-North Water Diversion Project—to delve into these scientific inquiries. In this study, we utilize a limited amount of GNSS data to address InSAR atmospheric errors and employ a weighted least squares time series inversion method to enhance the robustness of the deformation time series. Furthermore, a blind source separation technique named Independent Component Analysis (ICA) is applied to separate mixed signals of InSAR, successfully isolating deformation signals from both the sand and clay layers within the aquifer system, as well as those induced by environmental loadings. These approaches significantly facilitate the exploration of the interactive processes between groundwater dynamics and strata deformation. The result reveals a complex relationship between GWL and surface deformation during the aquifer system’s recovery stage due to the distinct responses of the sand and clay layers to groundwater dynamics. We find that during the restoration phase of aquifer system (when recharge exceeds discharge), the sand layers undergo recovery and rebound firstly, while weakly permeable clay layers continue to consolidate.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"75 11","pages":"Pages 7847-7862"},"PeriodicalIF":2.8,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143936112","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":"Determining geocenter motion using combined ground and spaceborne GPS observations with ambiguity resolution","authors":"Shiwei Guo ,&nbsp;Lei Fan ,&nbsp;Zongnan Li ,&nbsp;Xinqi Fang ,&nbsp;Chenshu Huo ,&nbsp;Chuang Shi","doi":"10.1016/j.asr.2025.03.038","DOIUrl":"10.1016/j.asr.2025.03.038","url":null,"abstract":"<div><div>Owing to the dense global tracking network and the abundant satellites providing continuous observations, the Global Navigation Satellite System (GNSS) has the potential to measure geocenter motion. However, the high altitude of GNSS satellites and the estimation of phase ambiguities compromise the quality of the estimated geocenter coordinates (GCC). This study conducted a combined zero-difference processing of ground observations from 98 global stations and spaceborne observations from four low Earth orbiters (LEOs), investigating the impact of integer ambiguity resolution and LEO configuration on GPS-derived GCC estimates. The ambiguity resolution in the double-difference mode between ground stations and one LEO can significantly improve the observability of GCC estimates, reducing the formal errors by 69.4 %, 69.4 % and 55.0 % for the X, Y and Z components, respectively. The faster relative motion between LEO and GPS satellites contributes to a faster change of tracking geometry. Integrating four LEOs into ground network, the formal errors of GCC parameters are reduced by 77.8 %, 78.2 % and 50.5 % for the X, Y and Z components, respectively. For the most concerned GCC Z component, its correlation with the B_1C empirical parameter is reduced from 0.69 to 0.41, demonstrating that the GCC Z component is more separable from the orbital parameters. Besides, the 5th and 7th draconitic harmonics of the Z component are mitigated by 67.0 % and 73.5 %, respectively. The derived annual signal shows a good consistency with the external SLR-based solution, and the amplitude differences are only 0.9 mm, 1.6 mm and 1.2 mm for the X, Y and Z components, respectively.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"75 11","pages":"Pages 7903-7916"},"PeriodicalIF":2.8,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143936115","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":"Catchment scale land use and hydrogeomorphology relationship in assessing river water quality using SWAT and RDA modelling in the Damodar River basin, West Bengal, India","authors":"Souvanik Maity ,&nbsp;Ramkrishna Maiti ,&nbsp;Sourav Mukherjee","doi":"10.1016/j.asr.2025.03.036","DOIUrl":"10.1016/j.asr.2025.03.036","url":null,"abstract":"<div><div>Identifying the sources of river water pollution is the initial step to ensure access to clean water for the population. Water drops from a distinct place in the basin that reaches the river, resulting from the interaction of rainfall, slope, soil, groundwater, etc., with the land use of the basin. Non-point sources of pollution are affected by local geomorphology controlled by local climate. The SWAT model considers all the land use classes and physical parameters to estimate the discharge, runoff, groundwater flow, etc. All these affect non-point sources of pollution. Multiple Linear Regression (MLR) and Redundancy Analysis (RDA) determine the most significant variables among the eight (industries and urban areas, open land, vegetation cover, discharge, groundwater flow, water yield, runoff, and distance from industries and urban areas) water quality factors. MLR and RDA (in step mode) filter only significant variables that control the 24 water quality parameters in pre-monsoon, monsoon, and post-monsoon seasons. In the pre-monsoon (dry) season, the adjusted R² value is 0.42 higher than the other seasons due to the dominance of point sources of pollution. Pollution load decreases with increased distance from the point sources of pollution. MLR and RDA identify industries and urban areas as the dominant pollution sources in the Damodar River basin. The contribution of groundwater reduces the pollution load in pre-monsoon season but increases the turbidity in river water. The agricultural area significantly affects pollution during the monsoon season due to the washout effect from non-point sources of pollution. Vegetation cover is capable of substantially reducing the pollution load. The research findings can help understand the importance of non-point sources of pollution that can be mitigated through land use management practices.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"75 11","pages":"Pages 7889-7902"},"PeriodicalIF":2.8,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143936114","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}