Advances in Space Research最新文献

{"title":"Phase space deep neural network with Saliency-based attention for hyperspectral target detection","authors":"Maryam Imani ,&nbsp;Daniele Cerra","doi":"10.1016/j.asr.2024.12.037","DOIUrl":"10.1016/j.asr.2024.12.037","url":null,"abstract":"<div><div>The accurate separation of targets and background is challenging in hyperspectral target detection algorithms, due to the high variability and complex non-linear scattering interactions in spectra acquired by imaging spectrometers. Moreover, the target regions may be contaminated by the background signal in real images, hindering the separation of a specific target in a scene. To address these challenges, a deep neural network is proposed in this work, consisting of three modules. First, to extract features hidden in the spectral signature of pixels, the hyperspectral image is considered as a dynamic system, and its phase space is reconstructed in the spectral feature space. Subsequently, in order to highlight the targets and suppress the background, a saliency map is produced, which shows candidate regions for the targets of interest. The saliency map is then utilized as an attention map for weighting the hyperspectral input within the network. The proposed multi-branch deep neural network processes each dimension of the reconstructed phase space. The resulting Phase Space Deep Neural Network with Saliency-based Attention (PSDNN-SA) outperforms several state-of-the-art detectors both quantitatively and visually in experiments carried out on different real hyperspectral subsets.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"75 4","pages":"Pages 3565-3588"},"PeriodicalIF":2.8,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143403142","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":"Comprehensive analysis of different GNSS receivers performance based on PPP-AR and positioning accuracy during 22 geomagnetic storms in 2023","authors":"Zhuang Chen ,&nbsp;Xiaomin Luo ,&nbsp;Xinmei Liang ,&nbsp;Yujie Li ,&nbsp;Yingzong Lin ,&nbsp;Shaofeng Bian","doi":"10.1016/j.asr.2024.11.067","DOIUrl":"10.1016/j.asr.2024.11.067","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Geomagnetic storms induced ionospheric disturbances can degrade the positioning accuracy and Ambiguity Resolution (PPP-AR) of GPS Precise Point Positioning (PPP), and this negative effect varies among different GNSS receivers. Under current conditions with frequent geomagnetic storms occurrences during the peak of solar cycle 25, selecting GNSS receivers with strong resistance to ionospheric disturbances is meaningful for precise GNSS positioning and ionospheric research. Therefore, it is necessary to conduct a comprehensive comparison and evaluation of the performance for different GNSS receivers under geomagnetic storms. Based on 22 geomagnetic storms in 2023, we investigated the three-dimensional root mean square error (3D RMS) and ambiguity resolved percentage (ARP), which is defined as the ratio of the number of carrier-phase observations with fixed ambiguities to the total number of phase measurements of GPS kinematic PPP, across ten groups of collocated stations around the world. For the groups using different receiver brands, the performance ranking for positioning accuracy and PPP-AR during geomagnetic storms are as follows: TPS &gt; JVAVD &gt; SEPTENTRIO &gt; TRIMBLE. The station with a larger average ARP generally has a smaller average 3D RMS error than the another GNSS station. The average 3D RMS error between collocated stations using different receiver brands is typically greater than 0.010 m and even larger. The largest 3D RMS error difference is observed between collocated stations with SEPTENTRIO and JAVAD receivers, with 3D RMS errors of 0.089 m and 0.019 m, respectively. These identical-brand receivers with different types are as follows: TPS NET-G5 &gt; TPS NET-G3A, TRIMBLE ALLOY &gt; TRIMBLE NETRS, SEPT POLARX5TR &gt; SEPT POLARX5S, and LEICA GR10 &gt; LEICA GR30, respectively. The average differences in 3D RMS and ARP can reach up to 0.021 m and 6.0 %, respectively. We found that the choice of antennas does not significantly affect PPP positioning performance during storms, with differences in average 3D RMS below 0.005 m and ARP differences below 0.2 %.. Higher latitudes have more satellites affected by ionospheric disturbances, while this effect is typically only observed during strong storms (&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;Dst&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;min&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;≤&lt;/mo&gt;&lt;mo&gt;-&lt;/mo&gt;&lt;mn&gt;100&lt;/mn&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;) in mid-latitudes. Adequate available GPS satellites are crucial for achieving high PPP-AR and positioning accuracy during storms. The variations of disturbed satellites and the average Rate of Total Electron Content Index (ROTI) for collocated stations are generally consistent. However, there are differences in the average of ROTI values for different receivers under geomagnetic storms. The differences in PPP-AR performance and ROTI values among different receivers under geomagnetic storms can be attributed to the variations in satellite tracking algorithms, tracking loo","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"75 4","pages":"Pages 3630-3650"},"PeriodicalIF":2.8,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143403146","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":"Toward the optimal spatial resolution ratio for fusion of UAV and Sentinel-2 satellite imageries using metaheuristic optimization","authors":"Ahmad Toosi ,&nbsp;Farhad Samadzadegan ,&nbsp;Farzaneh Dadrass Javan","doi":"10.1016/j.asr.2025.02.019","DOIUrl":"10.1016/j.asr.2025.02.019","url":null,"abstract":"<div><div>Sentinel-2A/2B twin satellites provide multispectral imagery every 5 days at a medium spatial resolution (10 m for visible and near-infrared bands). In contrast, UAV photogrammetry with low-cost visible-light (RGB) sensors produces ultra-high-resolution orthomosaics but lacks rich spectral information. Fusing these datasets is a solution to enhance the resolution of Sentinel imagery using UAV data. However, fusion is challenging due to large spatial resolution disparities, particularly in Ground Sampling Distance (GSD). By challenging the common practice of sharpening the Sentinel image to match the UAV resolution, we propose a method that fuses the two images at an intermediate resolution level where their information content is comparable. Our approach uses natural target edge analysis and a Genetic-based metaheuristic optimization technique. By minimizing an objective function comprising true GSD or Ground Resolved Distance (GRD) and Mutual Information (MI), we determine the optimal resolution level for fusion. Experimental validation on two UAV and Sentinel datasets, yielded optimal GRD estimates of 2.35 m and 2.03 m, respectively, with Sentinel GRD values of 12.12 m and 12.39 m. The optimal UAV-Sentinel GRD ratios were 0.193 and 0.164. The sharpened Sentinel images showed efficient fusion through subjective and objective quality assessments. Testing the method on 24 UAV-Sentinel datasets from various regions, including America (United States), Europe (Germany, Spain, and Switzerland), and Asia (Iran and Qatar), demonstrated its robustness across different land covers and sensor types. This approach can be applied to any multi-sensor remote sensing image fusion task with significant resolution differences, establishing the meaningful level for fusion.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"75 7","pages":"Pages 5254-5282"},"PeriodicalIF":2.8,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143683624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficient area coverage planning using approximation tiling heuristics for mosaic imaging with agile spacecraft","authors":"Paula Betriu ,&nbsp;Manel Soria ,&nbsp;Jordi L. Gutiérrez ,&nbsp;Diego Andía ,&nbsp;Marcel Llopis","doi":"10.1016/j.asr.2024.12.024","DOIUrl":"10.1016/j.asr.2024.12.024","url":null,"abstract":"<div><div>This work focuses on the Area Coverage Planning Problem (ACPP) for optical cameras onboard agile spacecraft in space exploration missions. The objective is to determine the optimal observation path of the camera’s boresight to obtain a mosaic that fully covers a designated Region Of Interest (ROI) on the target’s surface, while considering activity makespan and computational demand. To tackle this problem, four improved heuristics are implemented, each addressing differently the need to create an acquisition plan that dynamically adjusts to the camera’s observation geometry over time. Based on the proposal from a previous study, these heuristics have been further refined to correct spatial distortion and improve computational efficiency. In consequence, the current implementation allows for application to non-convex, irregularly shaped celestial bodies. We have developed a comprehensive program framework with supporting functions and assets to enable the iterative execution of the applied heuristics under diverse observation geometries along the spacecraft’s trajectory, ensuring their robustness and adaptability.</div><div>The ACPP is a component of a broader scheduling problem for agile spacecraft, which aims to maximize the scientific return while adhering to geometric and operational constraints imposed by both the spacecraft and its payload. In this context, deterministic step-stare algorithms are preferred for their efficiency in balancing accuracy and computational resources.</div><div>The algorithms are showcased through the simulation of observations from Galileo during one of its flybies over Europa. Arbitrary and diverse ROIs are considered on the target’s surface, allowing for a comprehensive evaluation of the algorithms in different observation geometries. The outcomes are analyzed over coverage completeness, efficient planning and computational burden. Thus, the resulting mosaics provide insights into the optimal usage of the heuristics in specific circumstances.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"75 4","pages":"Pages 4013-4034"},"PeriodicalIF":2.8,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143402758","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 robust GNSS velocity estimation method combining Doppler and carrier phase observations in complex urban environments","authors":"Yantao Liang ,&nbsp;Xiaohong Zhang ,&nbsp;Ying Liu ,&nbsp;Xianlu Tao ,&nbsp;Wanke Liu ,&nbsp;Hailu Jia ,&nbsp;Hongxia Bai","doi":"10.1016/j.asr.2024.11.071","DOIUrl":"10.1016/j.asr.2024.11.071","url":null,"abstract":"<div><div>Accurate and reliable velocity information is crucial for kinematic positioning, as it not only characterizes the carrier state but also serves as constraint information for positioning. However, due to the influence of low-cost Global Navigation Satellite System (GNSS) chips and complex environments, GNSS signals are prone to attenuation and interruptions. Consequently, frequent gross errors and cycle slips occur in observations, significantly degrading the velocity precision and reliability. To address this challenge, we have proposed a method combining Doppler and Time-Differenced Carrier Phase Velocity Estimation (D-TDCPVE). First, we assess the accuracy of both Doppler and carrier phase observations to determine the appropriate weight ratio for their combination. Second, we analyze the correlation between the two observation types and propose an adaptive parameter estimation strategy for estimating one or two clock bias variations to address their potential differences. Finally, we incorporate a combination of pre- and post-detection quality control measures along with additional cycle slip parameters to mitigate the impact of gross errors and cycle slips in complex environments. Experimental results conducted with three low-cost devices in urban environments demonstrate the superior performance of the D-TDCPVE method over both Doppler velocity estimation (DVE) and time-differenced carrier phase velocity estimation (TDCPVE). It enhances the success rate of velocity estimation by 3.3% to 20.1% compared to TDCPVE and improves velocity estimation accuracy by 16.1% to 60.9% compared to DVE. Moreover, the method does not necessitate the combination of dual-frequency observations, making it particularly valuable for cycle slip detection in scenarios involving mixed single- and dual-frequency observations, which is particularly useful in urban environments.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"75 4","pages":"Pages 3838-3855"},"PeriodicalIF":2.8,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143402865","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":"DAI algorithm: A QGIS plugin for daily aerial image interpolation","authors":"Tobías Romero-Macías ,&nbsp;C. Amurrio-García ,&nbsp;José L. Jiménez-García ,&nbsp;Pablo Blanco-Gómez","doi":"10.1016/j.asr.2024.11.081","DOIUrl":"10.1016/j.asr.2024.11.081","url":null,"abstract":"<div><div>This article describes the Daily Aerial Image (DAI) algorithm, a QGIS plugin implemented in Python for satellite image interpolation. The presence of clouds and the time difference between two satellite images make it difficult to observe the Earth’s surface with remote sensors. To solve this problem, the spatial and temporal combination of two observed clean images may be of particular interest to GIS users and satellite image scientists. The DAI package uses tri-band raster images from two different dates to interpolate the intermediate images on a daily basis.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"75 4","pages":"Pages 3335-3339"},"PeriodicalIF":2.8,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143403037","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 lightweight prediction model for global ionospheric total electron content based on attention-BiLSTM","authors":"Chao Han ,&nbsp;Yaping Guo ,&nbsp;Ming Ou ,&nbsp;Dandan Wang ,&nbsp;Chenglong Song ,&nbsp;Ruimin Jin ,&nbsp;Weimin Zhen ,&nbsp;Peirui Bai ,&nbsp;Xiaorui Chong ,&nbsp;Xiaoni Wang","doi":"10.1016/j.asr.2024.11.066","DOIUrl":"10.1016/j.asr.2024.11.066","url":null,"abstract":"<div><div>The ionospheric total electron content (TEC) is a critical parameter for space weather and Global Navigation Satellite System (GNSS) applications. A Bidirectional Long Short-Term Memory neural network model with an added attention mechanism (BiLSTM-Attention) was developed in this study to predict 256 spherical harmonic coefficients (SHC). Input data for the forecasting model includes F10.7, Dst, and other feature parameters, along with a lightweight historical time series of SHC from the past day. The model output is the next day’s SHC. Then, we compare the results of SHC with those of the 1-day Center for Orbit Determination in Europe (CODE) prediction model. The correlation coefficient form model TEC with respect to the CODE TEC are 0.93 and 0.96 in 2018 and 2022, respectively, while the correlation coefficient of the 1-day CODE prediction model are 0.91 and 0.94. The results illustrate established model both in high and low solar activity years, and exhibiting enhanced robustness during geomagnetic storms. Furthermore, typical ionospheric structures such as Equatorial Ionization Anomaly (EIA) is well reproduced in the TEC prediction maps. Compared to C1PG, the proposed model offers a lighter computational load while maintaining competitive performance in global TEC prediction.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"75 4","pages":"Pages 3614-3629"},"PeriodicalIF":2.8,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143403145","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":"Review of deployment controllers for space tethered system","authors":"Aaron Aw Teik Hong ,&nbsp;Renuganth Varatharajoo ,&nbsp;Yew-Chung Chak","doi":"10.1016/j.asr.2024.11.061","DOIUrl":"10.1016/j.asr.2024.11.061","url":null,"abstract":"<div><div>This review article investigates the performance of newly designed controllers for Tethered Space Systems (TSS) deployment, comparing them to past and current research. Specifically, the study delves into the PD type controller, known for its simplicity and early development. While PD controllers adequately manage non-coplanar scenarios with external perturbations, they are limited to linearized cases. In contrast, advanced controllers like Sliding Mode Control (SMC) effectively handle TSS’s highly nonlinear dynamics due to their robust nature. The study introduces a sigma function, derived from Djebli’s literature, to regulate tether deployment rate and length across all controllers. Simulation results demonstrate the feasibility of controlling out-of-plane libration angles solely through the tether tension. Among the controllers tested, the advanced sigma-SMC exhibits superior accuracy during deployment, while the modified SMC deploys the tether fastest albeit with significant steady-state errors and deflection angles. Numerical results show that the original SMC controller performs well as the most fuel-efficient option. This comparison focuses solely on tether deployment with J2 and gravity-gradient perturbations, offering a foundation for further exploration into TSS missions, including factors like aerodynamic drag, solar radiation, third body perturbations, tether flexibility, and retrieval phase control, tailored to specific mission requirements.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"75 4","pages":"Pages 3933-3949"},"PeriodicalIF":2.8,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143402753","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":"Maximization of fundamental frequency for small satellite components layout design","authors":"Wei Cong,&nbsp;Bingxiao Du,&nbsp;Yong Zhao","doi":"10.1016/j.asr.2024.11.079","DOIUrl":"10.1016/j.asr.2024.11.079","url":null,"abstract":"<div><div>This paper proposes a bi-objective optimization method for the small satellite components layout optimization design, considering mass characteristics and fundamental frequency characteristics. Firstly, <span><math><mrow><mi>φ</mi></mrow></math></span> function is used to describe the geometry and position relationships between components, effectively addressing the non-overlap constraints among them. Then, the finite element method is used to calculate the stiffness and mass of the satellite load-bearing board to determine the fundamental frequency of the satellite. In addition, the paper designs a novel bi-objective optimization algorithm combined Diverse Gradient Optimization (DGO) algorithm with the Smart Normal Constraint (SNC) method, which simplifies the complex gradient calculation through semi-analytical sensitivity analysis. Finally, numerical examples validate the applicability and rationality of the proposed optimization method in solving bi-objective satellite components layout problems. The results show that the method can provide effective solutions for the layout design of small satellite components while considering both mass characteristics and fundamental frequency characteristics optimization.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"75 4","pages":"Pages 3967-3981"},"PeriodicalIF":2.8,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143402755","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":"Doppler velocity estimation based on the random sample consensus considering a prior dynamic model","authors":"Jing Guo,&nbsp;Ziyu Fan,&nbsp;Zhen Li,&nbsp;Qile Zhao","doi":"10.1016/j.asr.2024.12.027","DOIUrl":"10.1016/j.asr.2024.12.027","url":null,"abstract":"<div><div>Typically, centimeters per second (cm/s) accuracy can be achieved for velocity estimation based on time-differenced positioning, Doppler velocity, and the time-differenced carrier phase approach in open air conditions. However, velocity estimation performance can deteriorate due to non-line-of-sight (NLOS) signals, multipath effects, and other sources of interference in urban areas. We discuss a velocity estimation method based on the RANdom SAmple Consensus (RANSAC) algorithm and a prior dynamic model is proposed. RANSAC is used to isolate the observations affected by NLOS or multipath, while a prior dynamic model is implemented to provide proper velocity constraint. Vehicle kinematic experiments conducted in both open and complex urban environments demonstrate that the velocity accuracy in all three directions can be improved by over 40 % and centimeter-level velocity accuracy can be obtained in open areas. Moreover, the accuracy can be improved by 78.5 %, 78.5 %, and 68.4 % in the north, east, and up directions compared to that obtained by traditional single-point Doppler velocity, and 10.5 cm/s, 11.0 cm/s, and 14.3 cm/s accuracies are achieved in complex urban areas. Moreover, this method is also reasonably applicable to low-cost receivers.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"75 4","pages":"Pages 3471-3485"},"PeriodicalIF":2.8,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143402847","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}