Pub Date : 2025-11-05DOI: 10.1016/j.asr.2025.10.111
Yutao Zhang , Sa Li , Dandan Liu , Te Li , Juntao Yang
With the development of the national economy, the demand for electricity has increased sharply, and the mileage of high-voltage transmission lines has repeatedly reached new highs. Therefore, safe, efficient, and low-cost methods for line inspection have become particularly important. Airborne Light Detection and Ranging (LiDAR) technology, as a new type of remote sensing measurement technology, has been widely used in helicopter power line inspections, with its advantages in inspecting dangerous areas becoming increasingly prominent. Aiming at the fact that existing power line extraction methods from airborne LiDAR face issues with low levels of automation and poor accuracy, we develop a high-voltage power corridor extraction and reconstruction method from airborne LiDAR by taking transmission direction and pylon localization into consideration. The pipeline of the proposed method consists of five main parts: (1) Calculation of Normalized Height, (2) Block-Constraint 3D Voxel-Based Euclidean Clustering, (3) Linear Element Recognition, (4) Pylon Detection and (5) RANSAC-Based Model Reconstruction and Detection Refinement. As a result, entire high-voltage transmission corridors are successfully classified into transmission lines and other elements. From the qualitative and quantitative perspectives, experiments are conducted on four different types of high-voltage transmission corridors with flat or complex terrains from helicopter-borne LiDAR point clouds. Experimental results demonstrate its effectiveness in handling complex structures and improving the precision of transmission line identification and modeling, with the quality for all four types of scenes exceeding 80 %. Moreover, most of misclassified points are located within a radius of 30 m around pylons, with the quality of nearly 100.0 % for all four types of scenes.
{"title":"A high-voltage power corridor extraction and reconstruction method from airborne LiDAR via transmission direction and pylon localization","authors":"Yutao Zhang , Sa Li , Dandan Liu , Te Li , Juntao Yang","doi":"10.1016/j.asr.2025.10.111","DOIUrl":"10.1016/j.asr.2025.10.111","url":null,"abstract":"<div><div>With the development of the national economy, the demand for electricity has increased sharply, and the mileage of high-voltage transmission lines has repeatedly reached new highs. Therefore, safe, efficient, and low-cost methods for line inspection have become particularly important. Airborne Light Detection and Ranging (LiDAR) technology, as a new type of remote sensing measurement technology, has been widely used in helicopter power line inspections, with its advantages in inspecting dangerous areas becoming increasingly prominent. Aiming at the fact that existing power line extraction methods from airborne LiDAR face issues with low levels of automation and poor accuracy, we develop a high-voltage power corridor extraction and reconstruction method from airborne LiDAR by taking transmission direction and pylon localization into consideration. The pipeline of the proposed method consists of five main parts: (1) Calculation of Normalized Height, (2) Block-Constraint 3D Voxel-Based Euclidean Clustering, (3) Linear Element Recognition, (4) Pylon Detection and (5) RANSAC-Based Model Reconstruction and Detection Refinement. As a result, entire high-voltage transmission corridors are successfully classified into transmission lines and other elements. From the qualitative and quantitative perspectives, experiments are conducted on four different types of high-voltage transmission corridors with flat or complex terrains from helicopter-borne LiDAR point clouds. Experimental results demonstrate its effectiveness in handling complex structures and improving the precision of transmission line identification and modeling, with the quality for all four types of scenes exceeding 80 %. Moreover, most of misclassified points are located within a radius of 30 m around pylons, with the quality of nearly 100.0 % for all four types of scenes.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"77 2","pages":"Pages 1795-1814"},"PeriodicalIF":2.8,"publicationDate":"2025-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145814342","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}
Pub Date : 2025-11-05DOI: 10.1016/j.asr.2025.10.113
Chun Kiat Chang , Safari Mat Desa , Zeqian Feng , Yuk San Liew , Mohd Afzaihelmi Mohd Ariff , Muhammad Wafiy Adli Ramli , Mou Leong Tan
Gridded precipitation products (GPPs) serve as an important alternative data source in Earth sciences where observational data is limited, particularly in tropical regions. Understanding their reliability is essential for continuous improvement and for guiding researchers in their selection. This study aims to evaluate the performance of APHRODITE, NASA POWER, and ERA5 in estimating precipitation over the Padas River Basin (PRB), a region frequently affected by floods. The assessment covers both overall precipitation variability and extremes, employing continuous and categorical statistical metrics as well as a probability distribution function (PDF). The results show that the GPPs reasonably capture the temporal variability of monthly and annual precipitation from 1990 to 2014, with moderate to high correlation coefficients (CC). However, APHRODITE consistently underestimated precipitation, while NASA POWER tended to overestimate it. Moderate-intensity precipitation (5–20 mm/day) was generally overestimated by the GPPs, resulting in a high detection of precipitation days, but this also caused approximately 40 % of non-precipitation days to be misclassified as precipitation days. Moreover, the GPPs were less reliable in capturing precipitation extremes, as reflected in flood-related indices such as maximum one-day precipitation (Rx1day) and the frequency of heavy (R20mm) and extreme (R50mm) precipitation events, with low CC values and underestimated magnitudes. These findings suggest that the evaluated GPPs are appropriate for representing general precipitation patterns but less reliable for calculating precipitation extreme indices. Improvements in retrieval algorithms, observational calibration, and tropical process parameterization are recommended to enhance product reliability in the future.
{"title":"Performance assessment of three long-term gridded precipitation products for precipitation and extreme event analysis in the Padas River Basin, Malaysia","authors":"Chun Kiat Chang , Safari Mat Desa , Zeqian Feng , Yuk San Liew , Mohd Afzaihelmi Mohd Ariff , Muhammad Wafiy Adli Ramli , Mou Leong Tan","doi":"10.1016/j.asr.2025.10.113","DOIUrl":"10.1016/j.asr.2025.10.113","url":null,"abstract":"<div><div>Gridded precipitation products (GPPs) serve as an important alternative data source in Earth sciences where observational data is limited, particularly in tropical regions. Understanding their reliability is essential for continuous improvement and for guiding researchers in their selection. This study aims to evaluate the performance of APHRODITE, NASA POWER, and ERA5 in estimating precipitation over the Padas River Basin (PRB), a region frequently affected by floods. The assessment covers both overall precipitation variability and extremes, employing continuous and categorical statistical metrics as well as a probability distribution function (PDF). The results show that the GPPs reasonably capture the temporal variability of monthly and annual precipitation from 1990 to 2014, with moderate to high correlation coefficients (CC). However, APHRODITE consistently underestimated precipitation, while NASA POWER tended to overestimate it. Moderate-intensity precipitation (5–20 mm/day) was generally overestimated by the GPPs, resulting in a high detection of precipitation days, but this also caused approximately 40 % of non-precipitation days to be misclassified as precipitation days. Moreover, the GPPs were less reliable in capturing precipitation extremes, as reflected in flood-related indices such as maximum one-day precipitation (Rx1day) and the frequency of heavy (R20mm) and extreme (R50mm) precipitation events, with low CC values and underestimated magnitudes. These findings suggest that the evaluated GPPs are appropriate for representing general precipitation patterns but less reliable for calculating precipitation extreme indices. Improvements in retrieval algorithms, observational calibration, and tropical process parameterization are recommended to enhance product reliability in the future.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"77 2","pages":"Pages 1830-1844"},"PeriodicalIF":2.8,"publicationDate":"2025-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145814397","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}
Pub Date : 2025-11-05DOI: 10.1016/j.asr.2025.10.109
Heon-Young Chang
In this work, we have statistically explored the relationship between solar activity and the occurrence of both spotless days and active days. The analysis is performed using the latest version of the daily sunspot number data compiled by the Sunspot Index and Long-Term Solar Observations, covering the period from January 1818 to June 2025, spanning solar cycles 6–25. We have calculated linear correlation coefficients for various combinations of the numbers of spotless days and sunspot numbers, determined in different ways. The results show that the mean sunspot number for a solar cycle is more significantly anti-correlated with the number of spotless days compared with the yearly mean sunspot numbers at the solar maximum. Noting the feature that a weak solar cycle is typically considered to be led by a solar minimum with a large number of spotless days, solar cycles 16, 20, 21, 22, and 23 among strong ones appear somewhat weaker than expected based on the very small number of spotless days. Nonetheless, it turns out that the skewed distribution of monthly spotless days (%) from the cycles identified to be weaker than expected is closer to that from other strong cycles than from weak ones. It is also found that the occurrence rate of sunspots on an active day during solar cycles 16, 20, 21, 22, and 23 is suggested to be lower than that for other cycles.
{"title":"Sunspot numbers and spotless days around solar minimum","authors":"Heon-Young Chang","doi":"10.1016/j.asr.2025.10.109","DOIUrl":"10.1016/j.asr.2025.10.109","url":null,"abstract":"<div><div>In this work, we have statistically explored the relationship between solar activity and the occurrence of both spotless days and active days. The analysis is performed using the latest version of the daily sunspot number data compiled by the Sunspot Index and Long-Term Solar Observations, covering the period from January 1818 to June 2025, spanning solar cycles 6–25. We have calculated linear correlation coefficients for various combinations of the numbers of spotless days and sunspot numbers, determined in different ways. The results show that the mean sunspot number for a solar cycle is more significantly anti-correlated with the number of spotless days compared with the yearly mean sunspot numbers at the solar maximum. Noting the feature that a weak solar cycle is typically considered to be led by a solar minimum with a large number of spotless days, solar cycles 16, 20, 21, 22, and 23 among strong ones appear somewhat weaker than expected based on the very small number of spotless days. Nonetheless, it turns out that the skewed distribution of monthly spotless days (%) from the cycles identified to be weaker than expected is closer to that from other strong cycles than from weak ones. It is also found that the occurrence rate of sunspots on an active day during solar cycles 16, 20, 21, 22, and 23 is suggested to be lower than that for other cycles.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"77 2","pages":"Pages 2732-2738"},"PeriodicalIF":2.8,"publicationDate":"2025-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145814319","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}
Pub Date : 2025-11-05DOI: 10.1016/j.asr.2025.10.110
Dongling Ma , Zhenxin Lin , Qian Wang , Yifan Yu , Guoqiang Yu
Improving the capabilities of Ecosystem Services (ES) is crucial for biodiversity conservation and sustainable socio-economic development. This study utilized China’s annual land use data at 30-meter resolution from 1985 to 2023, released by Professors Yang Jie and Huang Xin of Wuhan University, to obtain land use data for 2005, 2010, 2015, and 2020. It assessed the ecosystem service value (ESV) of Shandong Province, An improved value equivalent factor method was applied to calculate the ESV, which increased from 1.733 × 1011 in 2005 to 1.84 × 1011 in 2020, with an average annual rise of 724.4 million. A spatial pattern characterized by lower ESV in the southwest and higher ESV in the northeast. Slope trend analysis revealed, with 90 % of the study area exhibiting insignificant changes. Among these, decreases (62 %) were more pronounced than increases (37 %). The CA-Markov model predicted a decline in arable land by 2025, primarily converting to forest (42.01 %) and water (34.60 %). Contribution analysis indicated that climate factors positively influenced ESV in 49 % of the area and negatively in 51 %, while human activities had positive and negative impacts in 38 % and 62 % of the area, respectively, with a stronger negative influence. The optimal parameter geodetector revealed that interactions between temperature, precipitation, GDP, and population density significantly amplified ESV impacts, despite similar individual effects. These findings elucidate the spatiotemporal dynamics of ESV and the roles of climatic and anthropogenic drivers, offering critical insights for regional ecological conservation and land use planning in Shandong Province.
{"title":"The spatio-temporal evolution of ecosystem service value and its driving factors analysis in Shandong Province of China","authors":"Dongling Ma , Zhenxin Lin , Qian Wang , Yifan Yu , Guoqiang Yu","doi":"10.1016/j.asr.2025.10.110","DOIUrl":"10.1016/j.asr.2025.10.110","url":null,"abstract":"<div><div>Improving the capabilities of Ecosystem Services (ES) is crucial for biodiversity conservation and sustainable socio-economic development. This study utilized China’s annual land use data at 30-meter resolution from 1985 to 2023, released by Professors Yang Jie and Huang Xin of Wuhan University, to obtain land use data for 2005, 2010, 2015, and 2020. It assessed the ecosystem service value (ESV) of Shandong Province, An improved value equivalent factor method was applied to calculate the ESV, which increased from 1.733 × 10<sup>11</sup> in 2005 to 1.84 × 10<sup>11</sup> in 2020, with an average annual rise of 724.4 million. A spatial pattern characterized by lower ESV in the southwest and higher ESV in the northeast. Slope trend analysis revealed, with 90 % of the study area exhibiting insignificant changes. Among these, decreases (62 %) were more pronounced than increases (37 %). The CA-Markov model predicted a decline in arable land by 2025, primarily converting to forest (42.01 %) and water (34.60 %). Contribution analysis indicated that climate factors positively influenced ESV in 49 % of the area and negatively in 51 %, while human activities had positive and negative impacts in 38 % and 62 % of the area, respectively, with a stronger negative influence. The optimal parameter geodetector revealed that interactions between temperature, precipitation, GDP, and population density significantly amplified ESV impacts, despite similar individual effects. These findings elucidate the spatiotemporal dynamics of ESV and the roles of climatic and anthropogenic drivers, offering critical insights for regional ecological conservation and land use planning in Shandong Province.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"77 2","pages":"Pages 1776-1794"},"PeriodicalIF":2.8,"publicationDate":"2025-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145814341","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}
Pub Date : 2025-11-05DOI: 10.1016/j.asr.2025.10.112
Kamyar Fuladlu
Background
Many studies have proven that rapid population growth accelerates urbanization and increased construction to accommodate newcomers. Meanwhile, rapid, unplanned, and extensive construction causes manipulation of Land-use Land-cover (LULC). In same time, LULC change may cause an increase in Land Surface Temperature (LST), and ultimately, an increase in LST leads to widespread negative environmental consequences.
Method
The following research is designed to develop a time-series method on Cyprus using remote sensing, Google earth engine application programming interface and geographic information system. The research will monitor the consequences of population changes on various environmental factors such as Land Surface Temperature (LST), Normalized Difference Vegetation Index (NDVI) and LULC. Furthermore, the present research gains importance by removing all political and ethnic boundaries in Cyprus.
Result
Based on the research outcomes, The highest LST means in the case of Cyprus were emitted by cropland cover, in contrast, the lowest LST mean was emitted by terra firma and open space water LULCs, where the NDVI means value is minimized. Moreover, the results showed that the Turkish-populated areas of Cyprus have experienced a greater population increase than the Greek-populated areas in the past twenty years, especially in the case of the Kyrenia region and to some extent in the Famagusta region.
{"title":"Population increase and raised of environmental consequences: A time series research in Cyprus","authors":"Kamyar Fuladlu","doi":"10.1016/j.asr.2025.10.112","DOIUrl":"10.1016/j.asr.2025.10.112","url":null,"abstract":"<div><h3>Background</h3><div>Many studies have proven that rapid population growth accelerates urbanization and increased construction to accommodate newcomers. Meanwhile, rapid, unplanned, and extensive construction causes manipulation of Land-use Land-cover (LULC). In same time, LULC change may cause an increase in Land Surface Temperature (LST), and ultimately, an increase in LST leads to widespread negative environmental consequences.</div></div><div><h3>Method</h3><div>The following research is designed to develop a time-series method on Cyprus using remote sensing, Google earth engine application programming interface and geographic information system. The research will monitor the consequences of population changes on various environmental factors such as Land Surface Temperature (LST), Normalized Difference Vegetation Index (NDVI) and LULC. Furthermore, the present research gains importance by removing all political and ethnic boundaries in Cyprus.</div></div><div><h3>Result</h3><div>Based on the research outcomes, The highest LST means in the case of Cyprus were emitted by cropland cover, in contrast, the lowest LST mean was emitted by terra firma and open space water LULCs, where the NDVI means value is minimized. Moreover, the results showed that the Turkish-populated areas of Cyprus have experienced a greater population increase than the Greek-populated areas in the past twenty years, especially in the case of the Kyrenia region and to some extent in the Famagusta region.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"77 2","pages":"Pages 1815-1829"},"PeriodicalIF":2.8,"publicationDate":"2025-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145814343","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}
Pub Date : 2025-11-05DOI: 10.1016/j.asr.2025.10.082
Zhen Lyu , Ningbo Wang , Zishen Li , Zhiyu Wang , Liang Wang , Bingcheng Liu
<div><div>The integrity characterization of precise orbit, clock, and phase bias products is critical for Global Navigation Satellite System (GNSS) high-precision and high-integrity positioning applications. While the uncombined Precise Point Positioning with Ambiguity Resolution (PPP-AR) model has been extensively studied for positioning, its application to construct test statistics for integrity monitoring has been rarely investigated. In this paper, the carrier-phase residuals derived from the BDS-3 uncombined PPP-AR model at B1I, B3I, B1C, and B2a frequencies are utilized as test statistics to monitor the integrity of precise orbit, clock, and phase bias products, rather than being employed as a positioning strategy. Furthermore, existing Integrity Support Message (ISM) frameworks were developed within the Advanced Receiver Autonomous Integrity Monitoring (ARAIM) concept and remain focused on civil aviation. In this paper, we propose a preliminary ISM design tailored to BDS-3 precise products, which can be further extended to other constellations to enable future high-integrity positioning applications. Based on three months of continuous GNSS observations in combination with precise satellite orbit, clock, and bias products, the ISM for BDS-3 is rigorously computed. The computed Quality Indicators (QI) include the means and standard deviations, satellite and constellation fault probabilities, and system availability and abnormality ratios. Using the two-step Gaussian overbounding method, the carrier-phase residuals yield mean values fluctuations within ±5E-4 m and standard deviations ranging from 0.010 m to 0.015 m. These two statistical indicators, together with the user-specified risk requirement, determine the detection thresholds, which serve as a key parameter for the computation of subsequent integrity parameters. Satellite fault probabilities vary between 2.45E-4 and 2.70E-3 as constrained by the scenario-specific risk requirements, whereas constellation fault probabilities remain nearly constant at values between 2.08E-5 and 2.22E-5. System availability is highly dependent on the alarm level, and stabilizes at around 99.94 % when the alarm level is 0.05 m or 0.07 m, whereas a lower threshold of 0.01 m results in complete system abnormality. Based on the detection thresholds, fault detection is first performed at the station-level for all monitored satellites. The set of detectable faults varies with the user’s risk requirement: at a risk probability of 1E-5, pulse and step faults exceeding 20 cm in orbit, 0.5 ns in clock, or 0.50 cycles in phase bias are generally detectable, whereas the detectability of ramp faults depends on their duration and slope. After station-level detection, a network-level decision is made by integrating the results from all stations to derive the final satellite Alarm Indicators (AI). The QI and AI jointly constitute the complete ISM, which can ultimately be broadcast to users for high-integrity positioning
{"title":"Characterization of BDS-3 precise orbit, clock and multi-frequency phase bias products for integrity monitoring","authors":"Zhen Lyu , Ningbo Wang , Zishen Li , Zhiyu Wang , Liang Wang , Bingcheng Liu","doi":"10.1016/j.asr.2025.10.082","DOIUrl":"10.1016/j.asr.2025.10.082","url":null,"abstract":"<div><div>The integrity characterization of precise orbit, clock, and phase bias products is critical for Global Navigation Satellite System (GNSS) high-precision and high-integrity positioning applications. While the uncombined Precise Point Positioning with Ambiguity Resolution (PPP-AR) model has been extensively studied for positioning, its application to construct test statistics for integrity monitoring has been rarely investigated. In this paper, the carrier-phase residuals derived from the BDS-3 uncombined PPP-AR model at B1I, B3I, B1C, and B2a frequencies are utilized as test statistics to monitor the integrity of precise orbit, clock, and phase bias products, rather than being employed as a positioning strategy. Furthermore, existing Integrity Support Message (ISM) frameworks were developed within the Advanced Receiver Autonomous Integrity Monitoring (ARAIM) concept and remain focused on civil aviation. In this paper, we propose a preliminary ISM design tailored to BDS-3 precise products, which can be further extended to other constellations to enable future high-integrity positioning applications. Based on three months of continuous GNSS observations in combination with precise satellite orbit, clock, and bias products, the ISM for BDS-3 is rigorously computed. The computed Quality Indicators (QI) include the means and standard deviations, satellite and constellation fault probabilities, and system availability and abnormality ratios. Using the two-step Gaussian overbounding method, the carrier-phase residuals yield mean values fluctuations within ±5E-4 m and standard deviations ranging from 0.010 m to 0.015 m. These two statistical indicators, together with the user-specified risk requirement, determine the detection thresholds, which serve as a key parameter for the computation of subsequent integrity parameters. Satellite fault probabilities vary between 2.45E-4 and 2.70E-3 as constrained by the scenario-specific risk requirements, whereas constellation fault probabilities remain nearly constant at values between 2.08E-5 and 2.22E-5. System availability is highly dependent on the alarm level, and stabilizes at around 99.94 % when the alarm level is 0.05 m or 0.07 m, whereas a lower threshold of 0.01 m results in complete system abnormality. Based on the detection thresholds, fault detection is first performed at the station-level for all monitored satellites. The set of detectable faults varies with the user’s risk requirement: at a risk probability of 1E-5, pulse and step faults exceeding 20 cm in orbit, 0.5 ns in clock, or 0.50 cycles in phase bias are generally detectable, whereas the detectability of ramp faults depends on their duration and slope. After station-level detection, a network-level decision is made by integrating the results from all stations to derive the final satellite Alarm Indicators (AI). The QI and AI jointly constitute the complete ISM, which can ultimately be broadcast to users for high-integrity positioning","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"77 2","pages":"Pages 2074-2093"},"PeriodicalIF":2.8,"publicationDate":"2025-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145814446","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}
Pub Date : 2025-11-05DOI: 10.1016/j.asr.2025.11.001
Anoop Kumar Mishra , Mohammad Suhail Meer , Nagaraju Vanganuru , Gajendra Kumar , Sourav Adhikary , Krishna Kumar Shukla
Wayanad, a hilly district in northern Kerala, experienced a series of devastating landslides on July 30, 2024, following intense and persistent rainfall. These events resulted in 336 fatalities and damage to over 1,500 houses and structures, marking one of Kerala’s deadliest natural disasters. This study utilizes multi-source satellite observations to assess the hydro-meteorological and land surface conditions leading to the event. High-resolution satellite rainfall data reveal a 620 % excess rainfall in July 2024, with over 500 mm of cumulative precipitation recorded between July 29–30, highlighting the extreme nature of the localized event. Analysis of land use and land cover (LULC) changes using high-resolution imagery shows a 72.3 % increase in built-up areas and a 63.9 % rise in deforested land from 2011 to 2024, indicating increasing anthropogenic pressure on the landscape. While the study does not quantify statistical relationships, it qualitatively links these LULC changes with the observed landslides. The findings underscore the growing vulnerability of mountainous regions to landslides under changing land use and extreme weather conditions. The study highlights the potential of integrating satellite rainfall data with land surface monitoring to enhance situational awareness and inform disaster risk reduction strategies.
{"title":"Assessing persistent heavy rainfall-triggered landslides in southern India in July 2024 through space-based observations","authors":"Anoop Kumar Mishra , Mohammad Suhail Meer , Nagaraju Vanganuru , Gajendra Kumar , Sourav Adhikary , Krishna Kumar Shukla","doi":"10.1016/j.asr.2025.11.001","DOIUrl":"10.1016/j.asr.2025.11.001","url":null,"abstract":"<div><div>Wayanad, a hilly district in northern Kerala, experienced a series of devastating landslides on July 30, 2024, following intense and persistent rainfall. These events resulted in 336 fatalities and damage to over 1,500 houses and structures, marking one of Kerala’s deadliest natural disasters. This study utilizes multi-source satellite observations to assess the hydro-meteorological and land surface conditions leading to the event. High-resolution satellite rainfall data reveal a 620 % excess rainfall in July 2024, with over 500 mm of cumulative precipitation recorded between July 29–30, highlighting the extreme nature of the localized event. Analysis of land use and land cover (LULC) changes using high-resolution imagery shows a 72.3 % increase in built-up areas and a 63.9 % rise in deforested land from 2011 to 2024, indicating increasing anthropogenic pressure on the landscape. While the study does not quantify statistical relationships, it qualitatively links these LULC changes with the observed landslides. The findings underscore the growing vulnerability of mountainous regions to landslides under changing land use and extreme weather conditions. The study highlights the potential of integrating satellite rainfall data with land surface monitoring to enhance situational awareness and inform disaster risk reduction strategies.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"77 2","pages":"Pages 1845-1852"},"PeriodicalIF":2.8,"publicationDate":"2025-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145814398","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}
Pub Date : 2025-11-04DOI: 10.1016/j.asr.2025.10.107
Sumanjit Chakraborty, Gopi K. Seemala
The present investigation is directed to explore the southern polar ionospheric responses to intense/strong space weather events and the corresponding correlations with plasma convection and auroral precipitation. The main phases of six geomagnetic storms occurring in the year 2023 (ascending phase of the present solar cycle) are considered for this study. The ionospheric Total Electron Content (TEC) measurements derived from GPS receivers covering the Antarctic region are used for probing the electron density perturbations during these events. Auroral precipitation maps are shown to understand the locations of the GPS stations with respect to particle precipitation. SuperDARN maps are shown to understand the effects of plasma convection over these locations. Correlation between the enhanced TEC observations with the auroral precipitation (R 0.31) and the plasma convection (R 0.88) reveals that the latter is more responsible for causing significant enhancements in the diurnal maximum values of TEC over the Antarctic region in comparison to the former. Therefore, this work shows correlation studies between two physical processes and ionospheric density enhancements over the under-explored south polar region under strong levels of geomagnetic activity during 2023.
{"title":"Ionospheric responses over the Antarctic region to intense space weather events: Plasma convection vs. auroral precipitation","authors":"Sumanjit Chakraborty, Gopi K. Seemala","doi":"10.1016/j.asr.2025.10.107","DOIUrl":"10.1016/j.asr.2025.10.107","url":null,"abstract":"<div><div>The present investigation is directed to explore the southern polar ionospheric responses to intense/strong space weather events and the corresponding correlations with plasma convection and auroral precipitation. The main phases of six geomagnetic storms occurring in the year 2023 (ascending phase of the present solar cycle) are considered for this study. The ionospheric Total Electron Content (TEC) measurements derived from GPS receivers covering the Antarctic region are used for probing the electron density perturbations during these events. Auroral precipitation maps are shown to understand the locations of the GPS stations with respect to particle precipitation. SuperDARN maps are shown to understand the effects of plasma convection over these locations. Correlation between the enhanced TEC observations with the auroral precipitation (R <span><math><mrow><mo>∼</mo></mrow></math></span> 0.31) and the plasma convection (R <span><math><mrow><mo>∼</mo></mrow></math></span> 0.88) reveals that the latter is more responsible for causing significant enhancements in the diurnal maximum values of TEC over the Antarctic region in comparison to the former. Therefore, this work shows correlation studies between two physical processes and ionospheric density enhancements over the under-explored south polar region under strong levels of geomagnetic activity during 2023.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"77 2","pages":"Pages 2602-2613"},"PeriodicalIF":2.8,"publicationDate":"2025-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145814283","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}
Pub Date : 2025-11-04DOI: 10.1016/j.asr.2025.10.106
M. Jishad, Smitha Ratheesh, Neeraj Agarwal, Neerja Sharma, Rashmi Sharma
This study investigates the importance of frequent sampling of sea surface salinity (SSS) by satellites through Observing System Simulation Experiments (OSSE). The OSSEs were conducted in the Indian Ocean, using a data-assimilative oceanic general circulation model with spatial and temporal resolutions in the simulated SSS, based on SMOS swath and time frame, ranging from 10 km to 40 km and 1 day to 5 day, respectively for the year 2014. The model run with Aquarius-derived SSS assimilation is used as the reference data. Daily data assimilation experiments were consistently showing smaller errors and higher correlations with the reference run compared to experiments using 3-day and 5-day intervals. It is observed that assimilation of high frequency SSS data has significant impact on the model SSS accuracy compared to spatial resolution. The Model tendency to overestimate SSS is noticed when temporal frequency of SSS observations decreased. The analysis highlights the importance of total number of data assimilated across experiments, with daily experiments incorporating significantly more data, resulting in lower errors. The study underlines the importance of high temporal and spatial frequency data assimilation to accurately capture salinity variations in dynamic regions particularly affected by land–ocean contamination and Radio Frequency Interference in satellite SSS.
本文通过观测系统模拟实验（OSSE）探讨了卫星频繁采样海面盐度的重要性。基于2014年10 km ~ 40 km和1 d ~ 5 d的SMOS带状带和时间框架，在模拟SSS中使用具有空间和时间分辨率的数据同化海洋环流模式在印度洋进行了osse。采用宝水瓶座SSS同化模型作为参考数据。与3天和5天间隔的实验相比，每日数据同化实验一致显示误差较小，与参考运行的相关性较高。与空间分辨率相比，高频SSS数据同化对模型SSS精度有显著影响。当SSS观测值的时间频率降低时，模型有高估SSS的趋势。分析强调了在实验中吸收的数据总数的重要性，每天的实验包含更多的数据，导致更低的误差。该研究强调了高时间和空间频率数据同化对于准确捕获动态区域的盐度变化的重要性，特别是受陆地-海洋污染和卫星SSS中射频干扰的影响。
{"title":"Impact of spatial and temporal resolution of satellite sea surface salinity measurements on ocean state prediction in the Tropical Indian Ocean; an OSSE framework using SMOS","authors":"M. Jishad, Smitha Ratheesh, Neeraj Agarwal, Neerja Sharma, Rashmi Sharma","doi":"10.1016/j.asr.2025.10.106","DOIUrl":"10.1016/j.asr.2025.10.106","url":null,"abstract":"<div><div>This study investigates the importance of frequent sampling of sea surface salinity (SSS) by satellites through Observing System Simulation Experiments (OSSE). The OSSEs were conducted in the Indian Ocean, using a data-assimilative oceanic general circulation model with spatial and temporal resolutions in the simulated SSS, based on SMOS swath and time frame, ranging from 10 km to 40 km and 1 day to 5 day, respectively for the year 2014. The model run with Aquarius-derived SSS assimilation is used as the reference data. Daily data assimilation experiments were consistently showing smaller errors and higher correlations with the reference run compared to experiments using 3-day and 5-day intervals. It is observed that assimilation of high frequency SSS data has significant impact on the model SSS accuracy compared to spatial resolution. The Model tendency to overestimate SSS is noticed when temporal frequency of SSS observations decreased. The analysis highlights the importance of total number of data assimilated across experiments, with daily experiments incorporating significantly more data, resulting in lower errors. The study underlines the importance of high temporal and spatial frequency data assimilation to accurately capture salinity variations in dynamic regions particularly affected by land–ocean contamination and Radio Frequency Interference in satellite SSS.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"77 2","pages":"Pages 1766-1775"},"PeriodicalIF":2.8,"publicationDate":"2025-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145814340","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}
This paper develops an enhanced robust Lyapunov-based model predictive control (LMPC) scheme for station-keeping of Halo orbits with consideration of bounded uncertainties and control constraints. This method integrates the idea of robust control Lyapunov function (RCLF) into nonlinear MPC to robustly stabilize the tracking error within the explicitly characterized stability region. Specifically, the RCLF dissipation condition is firstly derived to analyze the stabilizability of the system with undefined feedback control. This property allows to construct the control-law-independent robust controllable domain, inside which admissible control exists to stabilize the spacecraft under bounded uncertainties. Subsequently, a sampling-based search strategy is developed to estimate the robust controllable domain, thereby deriving two contraction constraints. By incorporating the two constraints, the enhanced LMPC can be formulated independently of specific auxiliary control laws, whose stability region is explicitly characterized and extended. It brings appealing advantages that alleviate hard-to-avoid conservatism in traditional methods, thus improving tracking performances. Theoretically, within the stability region, robust stability and recursive feasibility can be well guaranteed. Numerical simulations demonstrate that the enhanced LMPC can eventually stabilize spacecraft to Halo orbit under bounded uncertainties and control constraints. Compared with traditional methods, the proposed controller achieves a 3–5 times scale of stability region, and tracking errors are reduced by about 50%.
{"title":"Robust station-keeping for Halo orbits via auxiliary-controller-independent Lyapunov-based model predictive control","authors":"Zhitong Yu , Haibin Shang , Zichen Zhao , Yue Dong , Lusha Shi","doi":"10.1016/j.asr.2025.10.105","DOIUrl":"10.1016/j.asr.2025.10.105","url":null,"abstract":"<div><div>This paper develops an enhanced robust Lyapunov-based model predictive control (LMPC) scheme for station-keeping of Halo orbits with consideration of bounded uncertainties and control constraints. This method integrates the idea of robust control Lyapunov function (RCLF) into nonlinear MPC to robustly stabilize the tracking error within the explicitly characterized stability region. Specifically, the RCLF dissipation condition is firstly derived to analyze the stabilizability of the system with undefined feedback control. This property allows to construct the control-law-independent robust controllable domain, inside which admissible control exists to stabilize the spacecraft under bounded uncertainties. Subsequently, a sampling-based search strategy is developed to estimate the robust controllable domain, thereby deriving two contraction constraints. By incorporating the two constraints, the enhanced LMPC can be formulated independently of specific auxiliary control laws, whose stability region is explicitly characterized and extended. It brings appealing advantages that alleviate hard-to-avoid conservatism in traditional methods, thus improving tracking performances. Theoretically, within the stability region, robust stability and recursive feasibility can be well guaranteed. Numerical simulations demonstrate that the enhanced LMPC can eventually stabilize spacecraft to Halo orbit under bounded uncertainties and control constraints. Compared with traditional methods, the proposed controller achieves a 3–5 times scale of stability region, and tracking errors are reduced by about 50%.</div></div>","PeriodicalId":50850,"journal":{"name":"Advances in Space Research","volume":"77 2","pages":"Pages 2419-2446"},"PeriodicalIF":2.8,"publicationDate":"2025-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145814485","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}
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