Journal of Geodetic Science最新文献

Effect of satellite availability and time delay of corrections on position accuracy of differential NavIC 卫星可用性和校正时间延迟对差分 NavIC 定位精度的影响

IF 1.3

Journal of Geodetic Science Pub Date : 2024-01-01 DOI: 10.1515/jogs-2022-0169

Madhu Krishna Karthan, D. Kuna, Perumalla Naveen Kumar

{"title":"Effect of satellite availability and time delay of corrections on position accuracy of differential NavIC","authors":"Madhu Krishna Karthan, D. Kuna, Perumalla Naveen Kumar","doi":"10.1515/jogs-2022-0169","DOIUrl":"https://doi.org/10.1515/jogs-2022-0169","url":null,"abstract":"\u0000 The position accuracy of standalone Navigation with Indian Constellation (NavIC) may not be met for certain applications like civil aviation. To improve the position accuracy of the user receiver, the technique used is Differential NavIC, which makes use of Differential corrections. The position accuracy of the user receiver also depends on the satellite availability (i.e. number of satellites available at a certain time instant to estimate the user position) and delay in transmission of differential corrections. In this article, the analysis of differential NavIC using different numbers of visible satellites (satellite availability) and different time delays for transmission of corrections is carried out. For this analysis, three cases are considered, Case I is when all (six) NavIC satellites are visible, Case II is when five satellites (3 Geosynchronous Orbit (GSO) and 2 Geostationary Earth Orbit (GEO)) are visible, and Case III is when five satellites (3 GEO and 2 GSO) are visible. The comparative analysis for these three cases is carried out with respect to the position accuracy parameters and Geometric Dilution of Precision. It is observed that, with the satellite availability in case I and case III, the user receiver accuracy is approximately the same. In case III, the accuracy of the user receiver (3.08 m) is similar to the accuracy (3.09 m) in case I. For time delay in transmission of corrections, different time delays (0, 5, 10, 20, …, 300 s) are considered to observe the effect on the positional accuracy of the user receiver. Due to the increase in this time delay, there is a significant degradation in the user receiver position accuracy of differential NavIC.","PeriodicalId":44569,"journal":{"name":"Journal of Geodetic Science","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140524308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Displacement analysis of the October 30, 2020 (M w = 6.9), Samos (Aegean Sea) earthquake 2020 年 10 月 30 日萨摩斯（爱琴海）地震（M w = 6.9）的位移分析

IF 1.3

Journal of Geodetic Science Pub Date : 2024-01-01 DOI: 10.1515/jogs-2022-0166

A. Çırmık, O. Ankaya Pamukçu, F. Doğru, A. Cingöz, Ö. Özdağ, H. Sözbilir

{"title":"Displacement analysis of the October 30, 2020 (M\u0000 w = 6.9), Samos (Aegean Sea) earthquake","authors":"A. Çırmık, O. Ankaya Pamukçu, F. Doğru, A. Cingöz, Ö. Özdağ, H. Sözbilir","doi":"10.1515/jogs-2022-0166","DOIUrl":"https://doi.org/10.1515/jogs-2022-0166","url":null,"abstract":"\u0000 Destructive earthquakes with high deformations have occurred in the Aegean region since the historical period. The most destructive of these earthquakes in recent years is the October 30, 2020 (M\u0000 w = 6.9) Samos (Aegean Sea) earthquake. This earthquake affected a wide area and caused numerous losses of lives and property especially in Izmir city. For examining the effects of the earthquake, Global Navigation Satellite System (GNSS) data before, during, and after the earthquake were processed, and coseismic and postseismic displacement evaluations were made. Interferometric Synthetic Aperture Radar (InSAR) ascending, descending interferograms, line of sight velocity, and displacement maps were obtained for the earthquake-affected area. The GNSS and InSAR data were evaluated together, and the areas with subsidence and uplift were determined in conjunction with the fault zone. In addition, the horizontal displacements were analyzed by using Coulomb failure criteria, and peak ground displacements were obtained from the strong motion stations located in the study region. As a result, from all the displacement analyses, it was determined that high-amplitude energy was released, at the regional scale from Ayvalık in the North to Datça in the South after the earthquake, and this earthquake generated permanent deformation in the affected region.","PeriodicalId":44569,"journal":{"name":"Journal of Geodetic Science","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139632797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

On initial data in adjustments of the geometric levelling networks (on the mean of paired observations) 关于几何找平网络调整的初始数据（关于配对观测的平均值）

IF 1.3

Journal of Geodetic Science Pub Date : 2024-01-01 DOI: 10.1515/jogs-2022-0170

Vasil Cvetkov

引用次数: 0

GNSS interference monitoring and detection based on the Swedish CORS network SWEPOS 基于瑞典 CORS 网络的全球导航卫星系统干扰监测和探测 SWEPOS

IF 1.3

Journal of Geodetic Science Pub Date : 2024-01-01 DOI: 10.1515/jogs-2022-0157

K. Abraha, Anders Frisk, Peter Wiklund

{"title":"GNSS interference monitoring and detection based on the Swedish CORS network SWEPOS","authors":"K. Abraha, Anders Frisk, Peter Wiklund","doi":"10.1515/jogs-2022-0157","DOIUrl":"https://doi.org/10.1515/jogs-2022-0157","url":null,"abstract":"\u0000 The presence of Global Navigation Satellite System (GNSS) interference poses a significant risk to both GNSS and the infrastructures that depend on them. This article describes how an existing GNSS infrastructure, the Swedish Continuously Operating Reference Stations network SWEPOS with more than 500 stations, can be leveraged to control the quality of GNSS signals and to be able to detect interferences in GNSS and adjacent frequency bands. This study introduces a SWEPOS-based automatic system that effectively detects GNSS interference by examining the signal-to-noise ratio (SNR) of Global Positioning System, Globalnaya Navigatsionnaya Sputnikovaya Sistema, Galileo, and BeiDou frequency bands. By comparing the SNR of tracked satellites against historical data, the system detects radio frequency interference (RFI) by statistically characterizing the SNR of simultaneously tracked satellites. Furthermore, based on the SNR characteristics across satellites, the system distinguishes between RFI and non-RFI sources. The effectiveness of the detection system is demonstrated through both simulated signal interference waves and real-world interference events.","PeriodicalId":44569,"journal":{"name":"Journal of Geodetic Science","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140519526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A field test of compact active transponders for InSAR geodesy 用于 InSAR 大地测量的紧凑型有源转发器现场测试

IF 1.3

Journal of Geodetic Science Pub Date : 2024-01-01 DOI: 10.1515/jogs-2022-0164

A. Meister, J. Balasis-Levinsen, K. Keller, M. R. V. Pedersen, J. P. Merryman Boncori, M. Jensen

{"title":"A field test of compact active transponders for InSAR geodesy","authors":"A. Meister, J. Balasis-Levinsen, K. Keller, M. R. V. Pedersen, J. P. Merryman Boncori, M. Jensen","doi":"10.1515/jogs-2022-0164","DOIUrl":"https://doi.org/10.1515/jogs-2022-0164","url":null,"abstract":"\u0000 Compact active transponders (CATs) – also termed electronic corner reflectors – are compact electronic devices designed to receive, actively amplify and re-transmit a radar signal, e.g. a C-band radar signal received from a Sentinel-1 satellite. CATs can potentially be useful for a number of purposes, e.g. if co-located with geodetic infrastructure. However, CATs have only recently become commercially available, and therefore, the usability and long-term performance of CATs are not well known. In this study, two CATs are tested under realistic operating conditions for a period of 14 months, from July 2020 to September 2021. The displacement time series of the CATs are determined from a persistent scatterers interferometric synthetic aperture radar processing of four tracks of Sentinel-1A/-1B data with a passive corner reflector (CR) as the spatial reference. The displacement time series of the CATs are evaluated against a ground truth established from repeated levellings between the CR and the CATs. Based on the results of this study, it is found that a sudden vertical displacement of a CAT can be determined with an accuracy better than 1 cm, possibly a few millimetres. Furthermore, it is found that the mean vertical velocity of a CAT, calculated from 14 months of interferometric synthetic aperture radar displacement time series, can be determined with an accuracy of a few mm/year. Finally, the line of sight (LoS) phase error is generally found to be moderately correlated with temperature, with an instrument-specific linear relationship between LoS error and temperature ranging between approx. 0.1 and 0.2 mm/°C. This correlation between LoS phase error and temperature can in principle be used for instrument-specific calibrations, which is a topic that should be addressed in future studies.","PeriodicalId":44569,"journal":{"name":"Journal of Geodetic Science","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139636584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Estimating the slip rate in the North Tabriz Fault using focal mechanism data and GPS velocity field 利用焦点机制数据和 GPS 速度场估算北大不里士断层的滑移率

IF 1.3

Journal of Geodetic Science Pub Date : 2024-01-01 DOI: 10.1515/jogs-2022-0167

Milad Salmanian, Asghar Rastbood, M. Hossainali

{"title":"Estimating the slip rate in the North Tabriz Fault using focal mechanism data and GPS velocity field","authors":"Milad Salmanian, Asghar Rastbood, M. Hossainali","doi":"10.1515/jogs-2022-0167","DOIUrl":"https://doi.org/10.1515/jogs-2022-0167","url":null,"abstract":"\u0000 This study delves into slip distribution on the North Tabriz Fault (NTF), a critical aspect of seismic hazard analysis due to its proximity to the Tabriz metropolis. The study operates within a uniform elastic half-space, maintaining constant values for fault geometry and regional rheological parameters throughout the research. To calculate strain boundary conditions, permanent and periodic global positioning system (GPS) data from the northwest region were utilized. The fault was constrained perpendicularly while allowing tangential movement, facilitating the determination of its annual slip rate using the boundary element method, with the Okada analytical model serving as the fundamental solution. The findings underscore the intricate relationship between the fault’s slip rate and boundary conditions, revealing a predominant right-lateral strike-slip motion. The study offers two slip rate assessments, obtained through earthquake focal mechanisms and GPS velocity data, yielding values of 5 and 5.5 \u0000 \u0000 \u0000 \u0000 \u0000 \u0000 mm\u0000 \u0000 /\u0000 \u0000 year\u0000 \u0000 \u0000 \u0000 {rm{mm}}/{rm{year}}\u0000 \u0000 , respectively. Importantly, the alignment of these calculated slip rates with paleo-seismological data underscores the credibility of the results generated via the boundary element method, distinguishing it as a reliable approach when compared to other numerical and analytical techniques. This research provides valuable insights into the behavior and slip dynamics of the NTF, which is pivotal for assessing seismic risks.","PeriodicalId":44569,"journal":{"name":"Journal of Geodetic Science","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140515699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The exact implementation of a spherical harmonic model for gravimetric quantities 重力测量量球面谐波模型的精确实施

IF 1.3

Journal of Geodetic Science Pub Date : 2024-01-01 DOI: 10.1515/jogs-2022-0161

Christopher Jekeli

引用次数: 0

Simulating VLBI observations to BeiDou and Galileo satellites in L-band for frame ties 模拟对北斗和伽利略卫星的 L 波段 VLBI 观测，以实现帧绑定

IF 1.3

Journal of Geodetic Science Pub Date : 2024-01-01 DOI: 10.1515/jogs-2022-0168

David Schunck, Lucia McCallum, G. Calves

{"title":"Simulating VLBI observations to BeiDou and Galileo satellites in L-band for frame ties","authors":"David Schunck, Lucia McCallum, G. Calves","doi":"10.1515/jogs-2022-0168","DOIUrl":"https://doi.org/10.1515/jogs-2022-0168","url":null,"abstract":"\u0000 Using the very long baseline interferometry (VLBI) technique to observe Earth-orbiting satellites is a topic of increasing interest for the establishment of frame ties. We present a simulation study on VLBI observations to BeiDou and Galileo satellites in L-band to investigate the accuracy of inter-technique frame ties between VLBI and global navigation satellite system (GNSS). We employ a global network of 16 antennas equipped with dedicated L-band receivers capable of observing BeiDou’s B1 and B3 navigation signals and Galileo’s E1 and E6 navigation signals. Through extensive Monte Carlo simulations, we simulate 24-h sessions to determine the optimal ratio of satellite to quasar scans. The optimal schedule uses about 80–90% satellite sources. We find that the 10–20% observations of quasar sources improve the estimation of the troposphere and, consequently, the estimation of the antenna position. Combining the normal equations from seven 24-h sessions, we derive a 7-day solution. The average antenna position repeatability is 7.3 mm. We identify the limitations of the results as the tropospheric turbulence, inaccuracies in the satellite orbit determination, and the lack of a more homogeneously distributed global network. This simulation study supports the understanding in the topic of building a frame tie using VLBI observations to GNSS satellites.","PeriodicalId":44569,"journal":{"name":"Journal of Geodetic Science","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140517919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The three Swedish kings of geodesy – Speech at the NKG General Assembly dinner in 2022 瑞典大地测量学三位之王——在2022年NKG大会晚宴上的讲话

IF 1.3

Journal of Geodetic Science Pub Date : 2023-01-01 DOI: 10.1515/jogs-2022-0152

L. Sjöberg

引用次数: 0

A gap-filling algorithm selection strategy for GRACE and GRACE Follow-On time series based on hydrological signal characteristics of the individual river basins 基于单个流域水文信号特征的GRACE和GRACE Follow-On时间序列补空算法选择策略

IF 1.3

Journal of Geodetic Science Pub Date : 2023-01-01 DOI: 10.1515/jogs-2022-0129

Hamed Karimi, S. Iran-Pour, A. Amiri-Simkooei, M. Babadi

{"title":"A gap-filling algorithm selection strategy for GRACE and GRACE Follow-On time series based on hydrological signal characteristics of the individual river basins","authors":"Hamed Karimi, S. Iran-Pour, A. Amiri-Simkooei, M. Babadi","doi":"10.1515/jogs-2022-0129","DOIUrl":"https://doi.org/10.1515/jogs-2022-0129","url":null,"abstract":"Abstract Gravity recovery and climate experiment (GRACE) and GRACE Follow-On (GRACE-FO) are Earth’s gravity satellite missions with hydrological monitoring applications. However, caused by measuring instrumental problems, there are several temporal missing values in the dataset of the two missions where a long gap between the mission dataset also exists. Recent studies utilized different gap-filling methodologies to fill those data gaps. In this article, we employ a variety of singular spectrum analysis (SSA) algorithms as well as the least squares-harmonic estimation (LS-HE) approach for the data gap-filling. These methods are implemented on six hydrological basins, where the performance of the algorithms is validated for different artificial gap scenarios. Our results indicate that each hydrological basin has its special behaviour. LS-HE outperforms the other algorithms in half of the basins, whereas in the other half, SSA provides a better performance. This highlights the importance of different factors affecting the deterministic signals and stochastic characteristics of climatological time series. To fill the missing values of such time series, it is therefore required to investigate the time series behaviour on their time-invariant and time-varying characteristics before processing the series.","PeriodicalId":44569,"journal":{"name":"Journal of Geodetic Science","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78161490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0