Journal of Applied Geodesy最新文献_第4页

Moho depth estimation of northern of East African Rift System 东非裂谷系北部莫霍深度估计

IF 1.4

Journal of Applied Geodesy Pub Date : 2023-08-22 DOI: 10.1515/jag-2023-0003

Eyasu Alemu

{"title":"Moho depth estimation of northern of East African Rift System","authors":"Eyasu Alemu","doi":"10.1515/jag-2023-0003","DOIUrl":"https://doi.org/10.1515/jag-2023-0003","url":null,"abstract":"Abstract The northern part of the East African Rift System is characterized by depleted Moho depth and thermally thinned lithosphere. This research aims to determine the Moho depth of the study area through non-linear gravity inversion and cross-validation with seismic Moho estimates. The study utilized gravity data to obtain the gravity anomaly of the Moho interface, a topographic grid for removing topographic effects, a crustal model to determine total sediment thickness and its gravitational effect, and seismic Moho depth for constraining the forward model and cross-validation. The estimated Moho depth of the study area ranges between 5 km (in the Indian Ocean) to 45 km (in the Ethiopian Highlands), with slight variation compared to seismic Moho relief. This is because the reference level, calculated for the thinner part of the study region, underestimates the entire area. Upwelling magma in the Eastern branches of the EARS may also incur slight variation in the estimated Moho depth; rifting, volcanism, melt intrusion, magmatic uplift, and tectonic setting all influence the Moho depth of the study area. Furthermore, reverberations affect most seismic Moho estimations in the region. The slight variation can be mitigated by improving the gravity network for accurate validation and precise heat flow measurement to correctly identify magmatic anomalies and density contrasts. Additionally, applying reverberation removal techniques in the study region could improve seismic Moho estimation.","PeriodicalId":45494,"journal":{"name":"Journal of Applied Geodesy","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45858859","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

Determination of a gravimetric geoid model for Eastern Province in the Kingdom of Saudi Arabia 沙特阿拉伯王国东部省重力大地水准面模型的确定

IF 1.4

Journal of Applied Geodesy Pub Date : 2023-08-14 DOI: 10.1515/jag-2023-0034

Ali Al Shehri, S. Mogren, E. Ibrahim, A. Zaki

引用次数: 0

Comparison of L1 and L5 GPS smartphone absolute positioning results L1和L5 GPS智能手机绝对定位结果的比较

IF 1.4

Journal of Applied Geodesy Pub Date : 2023-07-20 DOI: 10.1515/jag-2023-0039

M. Uradziński, M. Bakuła

{"title":"Comparison of L1 and L5 GPS smartphone absolute positioning results","authors":"M. Uradziński, M. Bakuła","doi":"10.1515/jag-2023-0039","DOIUrl":"https://doi.org/10.1515/jag-2023-0039","url":null,"abstract":"Abstract The paper presents the analysis of single-point GPS positioning results obtained from smartphones, using code observations on the L1 and L5 frequencies. In this research we used two Huawei P30 Pro mobile phones and one geodetic receiver (Javad Alpha) acting as the reference receiver. Smartphones were placed at an equal distance of 0.5 m from this receiver. Such a close distance was specially planned by the authors in order to achieve identical observation conditions. Thus, it was possible to compare the accuracy of GPS positioning using pseudoranges on the L1 and L5 frequencies for individual observation epochs. The analysis was carried out from static GPS positioning, using the results from the open-source RTKLib software. In general, the usefulness of code measurements on the L5 frequency to determine the GPS position made it possible to increase the accuracy by several times with respect to the positions determined using the C/A code on the L1 frequency. Average errors of horizontal and vertical coordinates were about 70 % lower for the GPS solution using the L5 code observations than using the L1 code observations. Based on statistical analysis, a horizontal accuracy of about 0.45 m and vertical accuracy of about 1.8 m (STDEV) with only five GPS satellites may be obtained using a smartphone with L5 code observations.","PeriodicalId":45494,"journal":{"name":"Journal of Applied Geodesy","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47897788","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

Integrity monitoring of NavIC by parsing broadcast ephemeris 基于广播星历分析的导航系统完整性监测

IF 1.4

Journal of Applied Geodesy Pub Date : 2023-07-12 DOI: 10.1515/jag-2023-0026

Sony Devalapally, Krishna Reddy Desireddy, Naveen Kumar Perumalla

{"title":"Integrity monitoring of NavIC by parsing broadcast ephemeris","authors":"Sony Devalapally, Krishna Reddy Desireddy, Naveen Kumar Perumalla","doi":"10.1515/jag-2023-0026","DOIUrl":"https://doi.org/10.1515/jag-2023-0026","url":null,"abstract":"Abstract Global navigation satellite systems (GNSS) are used to provide position estimation to the users. These navigation systems must meet the required navigation parameters (RNP) parameters. Among them integrity being the important parameter, defined as a navigation system’s honesty of the information provided to the user by satellites. The extremity of error due to clocks, ephemeris etc., broadcasted in navigation message of NavIC will result in inaccurate information provided by the satellites that tamper the Navigation with Indian constellation (NavIC) system integrity. The information provided by the satellites may be faulty due to various error sources and cannot be used for applications which require very high accuracy. Integrity of the information provided by satellites plays a vital role and the system needs to be notified accordingly. The traditional methods receiver autonomous integrity monitoring (RAIM) algorithms require both navigation and observation data for implementation and involves several computations, hence in this paper an efficient approach considering only navigation message is proposed to monitor the integrity of NavIC. The NavIC Navigation data of 28 days data corresponding to 4 months is collected from IGS website. The integrity check is performed considering the satellite‘s User Range Accuracy Upper Bound (URA UB), fit interval and health parameters from navigation message. It is observed from the results that there are specific instances of integrity failure of NavIC system. However, it is also noticed that 99.5 % of times the integrity provided by NavIC is within specified limits that guarantee the NavIC utility for critical applications.","PeriodicalId":45494,"journal":{"name":"Journal of Applied Geodesy","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44823339","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 novel approach to enhancing the Klobuchar algorithm to mitigate the effect of ionospheric delay errors on static single-frequency receivers 一种改进Klobuchar算法以减轻电离层延迟误差对静态单频接收机影响的新方法

IF 1.4

Journal of Applied Geodesy Pub Date : 2023-07-05 DOI: 10.1515/jag-2023-0031

H. T. Elshambaky

{"title":"A novel approach to enhancing the Klobuchar algorithm to mitigate the effect of ionospheric delay errors on static single-frequency receivers","authors":"H. T. Elshambaky","doi":"10.1515/jag-2023-0031","DOIUrl":"https://doi.org/10.1515/jag-2023-0031","url":null,"abstract":"Abstract The demand for real-time high-precision positioning for global navigation satellite system applications is difficult to satisfy. In this regard, a single-frequency receiver is found to play an important role in overcoming this challenge, especially in developing countries where economic factors are a major restriction. Hence, the development of built-in models, such as the Klobuchar model, is an important objective for single-frequency users to mitigate the effect of ionospheric delay errors in real-time applications. Accordingly, this study aims to devise a new approach to enhance the behavior of the Klobuchar model and increase its efficiency in resolving the aforementioned problem. The new approach seeks to enhance the behavior of the Klobuchar model without refining or increasing its coefficients. To eliminate the ionospheric delay disturbance, the proposed methodology applies normalization and filtration processes to the raw ionospheric delay probability distribution estimated by the unified least squares technique. A final assessment of the new method for enhancing the Klobuchar behavior in predicting the precise position of a single-frequency static receiver under different weather conditions around the globe is presented in this paper.","PeriodicalId":45494,"journal":{"name":"Journal of Applied Geodesy","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46708604","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

Frontmatter 头版头条

Journal of Applied Geodesy Pub Date : 2023-06-30 DOI: 10.1515/jag-2023-frontmatter3

引用次数: 0

Assessing the influence of differential code bias and satellite geometry on GNSS ambiguity resolution through MANS-PPP software package 通过man - ppp软件包评估差分码偏差和卫星几何形状对GNSS模糊度分辨率的影响

IF 1.4

Journal of Applied Geodesy Pub Date : 2023-06-29 DOI: 10.1515/jag-2023-0032

Ashraf G. Shehata, F. Zarzoura, Mahmoud El-Mewafi

{"title":"Assessing the influence of differential code bias and satellite geometry on GNSS ambiguity resolution through MANS-PPP software package","authors":"Ashraf G. Shehata, F. Zarzoura, Mahmoud El-Mewafi","doi":"10.1515/jag-2023-0032","DOIUrl":"https://doi.org/10.1515/jag-2023-0032","url":null,"abstract":"Abstract Ambiguity resolution (AR) is essential for quick and accurate Global Navigation Satellite System GNSS location and navigation. In addition to location parameters, there are various additional GNSS characteristics that are relevant for a wide range of applications such as instrumental calibrations, atmospheric sounding, and time transfer. We offer differential code bias and satellite geometry for the GNSS estimable parameters using MANS-PPP software backage. In this research, we used the MANS-PPP software package to execute the processing method and generate the PPP GNSS solution. We demonstrated how differential code bias and satellite geometry can effectively enhance initial time and positioning error for multi-GNSS satellites. PPP Processing observation data in static mode was used by the different DCB files the Chinese Academy of Sciences (CAS), the German Aerospace Centre (DLR), and the Centre for Orbit Determination in Europe (CODE), for the 12 stations from IGS, and we analyzed the impact of errors from the satellite geometry. The results illustration that the correction of DCB significantly improves the PPP ambiguity resolution success rate and quality, which have higher DCB values. The satellite geometry also has a substantial influence on the PPP ambiguity resolution, with a better geometry leading to a higher success rate and quality. Furthermore, the use of multiple GNSS constellations and the optimization of the satellite selection and weighting algorithms can further improve the PPP ambiguity resolution and the resulting positioning accuracy.","PeriodicalId":45494,"journal":{"name":"Journal of Applied Geodesy","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43434644","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: 1

Modeling 3D crustal velocities in the vicinities of Alaska and the Bering sea 模拟阿拉斯加和白令海附近的三维地壳速度

IF 1.4

Journal of Applied Geodesy Pub Date : 2023-06-27 DOI: 10.1515/jag-2023-0004

R. Snay, J. Freymueller, M. L. Dennis

引用次数: 0

Comparative analysis of regression algorithms for the prediction of NavIC differential corrections NavIC微分校正预测回归算法的比较分析

IF 1.4

Journal of Applied Geodesy Pub Date : 2023-06-19 DOI: 10.1515/jag-2023-0025

Madhu Krishna Karthan, Naveen Kumar Perumalla

{"title":"Comparative analysis of regression algorithms for the prediction of NavIC differential corrections","authors":"Madhu Krishna Karthan, Naveen Kumar Perumalla","doi":"10.1515/jag-2023-0025","DOIUrl":"https://doi.org/10.1515/jag-2023-0025","url":null,"abstract":"Abstract Indian Regional Navigation Satellite System (IRNSS) or Navigation with Indian Constellation (NavIC) provides positioning, navigation and timing information services to various users in Indian region. Standalone NavIC may not meet the position accuracies for certain application such as civil aviation. Differential NavIC is used for improving the position accuracy of rover receiver, which make use of differential corrections (transmitted from reference station). However, if the satellite signals are temporarily lost due to abruptly changing atmosphere, satellite health issues or if the satellite signals are attenuated due to city infrastructures in urban areas, tree canopies, the accuracy of NavIC will be degraded. This article compares regression tree and bagging tree based differential corrections prediction algorithm with the actual differential corrections, by considering the NavIC satellite signal strength (C/No) and elevation angle (El), to improve the NavIC positioning accuracy. The improvement in the position accuracy is obtained by utilizing predicted differential corrections. The position accuracy of rover using actual differential corrections (2DRMS – 3.09 m), regression tree predicted differential corrections (2DRMS – 5.96 m) and bagged tree predicted differential corrections (2DRMS – 3.06 m) are compared. Here, the rover accuracy using actual differential corrections and bagged tree predicted differential corrections are approximately equal. So, the position accuracy using bagged tree predicted differential corrections are accurate when compared to regression tree predicted differential corrections.","PeriodicalId":45494,"journal":{"name":"Journal of Applied Geodesy","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49242848","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: 1

Implementation of the EVRF2007 height reference frame in Poland EVRF2007高度参考框架在波兰的实施

IF 1.4

Journal of Applied Geodesy Pub Date : 2023-06-12 DOI: 10.1515/jag-2023-0020

Łukasz Borowski, Bartosz Kubicki, J. Gołąb

引用次数: 1