Artificial Satellites-Journal of Planetary Geodesy最新文献_第7页

Regional Recovery of Gravity Anomaly from the Inversion of Diagonal Components of GOCE Gravitational Tensor: A Case Study in Ethiopia GOCE重力张量对角分量反演反演重力异常的区域恢复——以埃塞俄比亚为例

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Artificial Satellites-Journal of Planetary Geodesy Pub Date : 2018-06-01 DOI: 10.2478/arsa-2018-0006

M. Eshagh, Andenet A. Gedamu, T. Bedada

{"title":"Regional Recovery of Gravity Anomaly from the Inversion of Diagonal Components of GOCE Gravitational Tensor: A Case Study in Ethiopia","authors":"M. Eshagh, Andenet A. Gedamu, T. Bedada","doi":"10.2478/arsa-2018-0006","DOIUrl":"https://doi.org/10.2478/arsa-2018-0006","url":null,"abstract":"Abstract The tensor of gravitation is traceless as the gravitational field of the Earth is harmonic outside the Earth’s surface. Therefore, summation of the 2nd-order horizontal derivatives on its diagonal components should be equal to the radial one but with the opposite sign. The gravity field can be recovered locally from either of them, or even their combination. Here, we use the in-orbit diagonal components of the gravitational tensor measured by the gravity field and steady state ocean circulation explorer (GOCE) mission for recovering gravity anomaly with a resolution of 1°×1° at sea level in Ethiopia. In order to solve the system of equations, derived after discretisation of integral equations, the Tikhonov regularisation is applied and the bias of this regularisation is estimated and removed from the estimated gravity anomalies. The errors of the anomalies are estimated and their significance of recovery from these diagonal components is investigated. Statistically, the difference between the recovered anomalies from each scenario is not significant comparing to their errors. However, their joint inversion of the diagonal components improved the solution by about 1 mGal. Furthermore, the inversion processes are better stabilised when using errors of the input data compared with its exclusion, but at the penalty of degradation in accuracy of the estimates.","PeriodicalId":43216,"journal":{"name":"Artificial Satellites-Journal of Planetary Geodesy","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42703589","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: 2

Structural Analysis of Kufasat Using Ansys Program Kufasat的Ansys结构分析

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Artificial Satellites-Journal of Planetary Geodesy Pub Date : 2018-03-01 DOI: 10.2478/arsa-2018-0003

F. Al-Maliky, M. J. Albermani

引用次数: 3

Kinematic-PPP using Single/Dual Frequency Observations from (GPS, GLONASS and GPS/GLONASS) Constellations for Hydrography 利用(GPS, GLONASS和GPS/GLONASS)星座的单/双频观测进行水文测量的运动学ppp

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Artificial Satellites-Journal of Planetary Geodesy Pub Date : 2018-03-01 DOI: 10.2478/arsa-2018-0004

A. Farah

{"title":"Kinematic-PPP using Single/Dual Frequency Observations from (GPS, GLONASS and GPS/GLONASS) Constellations for Hydrography","authors":"A. Farah","doi":"10.2478/arsa-2018-0004","DOIUrl":"https://doi.org/10.2478/arsa-2018-0004","url":null,"abstract":"Abstract Global Positioning System (GPS) technology is ideally suited for inshore and offshore positioning because of its high accuracy and the short observation time required for a position fix. Precise point positioning (PPP) is a technique used for position computation with a high accuracy using a single GNSS receiver. It relies on highly accurate satellite position and clock data that can be acquired from different sources such as the International GNSS Service (IGS). PPP precision varies based on positioning technique (static or kinematic), observations type (single or dual frequency) and the duration of observations among other factors. PPP offers comparable accuracy to differential GPS with safe in cost and time. For many years, PPP users depended on GPS (American system) which considered the solely reliable system. GLONASS's contribution in PPP techniques was limited due to fail in maintaining full constellation. Yet, GLONASS limited observations could be integrated into GPS-based PPP to improve availability and precision. As GLONASS reached its full constellation early 2013, there is a wide interest in PPP systems based on GLONASS only and independent of GPS. This paper investigates the performance of kinematic PPP solution for the hydrographic applications in the Nile river (Aswan, Egypt) based on GPS, GLONASS and GPS/GLONASS constellations. The study investigates also the effect of using two different observation types; single-frequency and dual frequency observations from the tested constellations.","PeriodicalId":43216,"journal":{"name":"Artificial Satellites-Journal of Planetary Geodesy","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2018-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43742066","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: 6

Self-Shadowing of a Spacecraft in the Computation of Surface Forces. An Example in Planetary Geodesy 表面力计算中航天器的自阴影。行星大地测量的一个例子

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Artificial Satellites-Journal of Planetary Geodesy Pub Date : 2018-03-01 DOI: 10.2478/arsa-2018-0002

G. Balmino, J. Marty

引用次数: 0

A New Method for Measuring Angular Increments Based on a Tri-Axial Accelerometer and a Tri-Axial Magnetometer 基于三轴加速度计和三轴磁强计的角增量测量新方法

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Artificial Satellites-Journal of Planetary Geodesy Pub Date : 2018-03-01 DOI: 10.2478/arsa-2018-0005

X. Zhu, M. Ma, D. F. Cheng, Zhijian Zhou

引用次数: 0

EGNOS Monitoring Prepared in Space Research Centre P.A.S. for SPMS Project 空间研究中心为SPMS项目准备的EGNOS监测

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Artificial Satellites-Journal of Planetary Geodesy Pub Date : 2017-12-01 DOI: 10.1515/arsa-2017-0010

A. Świątek, L. Jaworski, L. Tomasik

引用次数: 5

Precise Receiver Clock Offset Estimations According to Each Global Navigation Satellite Systems (GNSS) Timescales 根据每个全球导航卫星系统(GNSS)时标的精确接收机时钟偏移估计

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Artificial Satellites-Journal of Planetary Geodesy Pub Date : 2017-12-01 DOI: 10.1515/arsa-2017-0009

Thayathip Thongtan, Pawit Tirawanichakul, C. Satirapod

{"title":"Precise Receiver Clock Offset Estimations According to Each Global Navigation Satellite Systems (GNSS) Timescales","authors":"Thayathip Thongtan, Pawit Tirawanichakul, C. Satirapod","doi":"10.1515/arsa-2017-0009","DOIUrl":"https://doi.org/10.1515/arsa-2017-0009","url":null,"abstract":"Abstract Each GNSS constellation operates its own system times; namely, GPS system time (GPST), GLONASS system time (GLONASST), BeiDou system time (BDT) and Galileo system time (GST). They could be traced back to Coordinated Universal Time (UTC) scale and are aligned to GPST. This paper estimates the receiver clock offsets to three timescales: GPST, GLONASST and BDT. The two measurement scenarios use two identical multi-GNSS geodetic receivers connected to the same geodetic antenna through a splitter. One receiver is driven by its internal oscillators and another receiver is connected to the external frequency oscillators, caesium frequency standard, kept as the Thailand standard time scale at the National Institute of Metrology (Thailand) called UTC(NIMT). The three weeks data are observed at 30 seconds sample rate. The receiver clock offsets with respected to the three system time are estimated and analysed through the geodetic technique of static Precise Point Positioning (PPP) using a data processing software developed by Wuhan University - Positioning And Navigation Data Analyst (PANDA) software. The estimated receiver clock offsets are around 32, 33 and 18 nanoseconds from GPST, GLONASST and BDT respectively. This experiment is initially stated that each timescale is inter-operated with GPST and further measurements on receiver internal delay has to be determined for clock comparisons especially the high accuracy clock at timing laboratories.","PeriodicalId":43216,"journal":{"name":"Artificial Satellites-Journal of Planetary Geodesy","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2017-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49077666","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: 9

Lifetime Performances of Modernized GLONASS Satellites: A Review 现代化GLONASS卫星的寿命性能综述

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Artificial Satellites-Journal of Planetary Geodesy Pub Date : 2017-12-01 DOI: 10.1515/arsa-2017-0008

S. Sarkar, A. Bose

引用次数: 7

Evaluation of Integration Degree of the ASG-EUPOS Polish Reference Networks With Ukrainian GeoTerrace Network Stations in the Border Area ASG-EUPOS波兰参考网与乌克兰GeoTerrace网络站在边境地区的整合程度评估

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Artificial Satellites-Journal of Planetary Geodesy Pub Date : 2017-09-26 DOI: 10.1515/arsa-2017-0007

Z. Siejka

{"title":"Evaluation of Integration Degree of the ASG-EUPOS Polish Reference Networks With Ukrainian GeoTerrace Network Stations in the Border Area","authors":"Z. Siejka","doi":"10.1515/arsa-2017-0007","DOIUrl":"https://doi.org/10.1515/arsa-2017-0007","url":null,"abstract":"Abstract GNSS systems are currently the basic tools for determination of the highest precision station coordinates (e.g. basic control network stations or stations used in the networks for geodynamic studies) as well as for land, maritime and air navigation. All of these tasks are carried out using active, large scale, satellite geodetic networks which are complex, intelligent teleinformatic systems offering post processing services along with corrections delivered in real-time for kinematic measurements. Many countries in the world, also in Europe, have built their own multifunctional networks and enhance them with their own GNSS augmentation systems. Nowadays however, in the era of international integration, there is a necessity to consider collective actions in order to build a unified system, covering e.g. the whole Europe or at least some of its regions. Such actions have already been undertaken in many regions of the world. In Europe such an example is the development for EUPOS which consists of active national networks built in central eastern European countries. So far experience and research show, that the critical areas for connecting these networks are border areas, in which the positioning accuracy decreases (Krzeszowski and Bosy, 2011). This study attempts to evaluate the border area compatibility of Polish ASG-EUPOS (European Position Determination System) reference stations and Ukrainian GeoTerrace system reference stations in the context of their future incorporation into the EUPOS. The two networks analyzed in work feature similar hardware parameters. In the ASG-EUPOS reference stations network, during the analyzed period, 2 stations (WLDW and CHEL) used only one system (GPS), while, in the GeoTerrace network, all the stations were equipped with both GPS and GLONASS receivers. The ASG EUPOS reference station network (95.6%) has its average completeness greater by about 6% when compared to the GeoTerrace network (89.8%).","PeriodicalId":43216,"journal":{"name":"Artificial Satellites-Journal of Planetary Geodesy","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2017-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42961642","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: 3

An Optimized Triad Algorithm for Attitude Determination 一种用于姿态确定的优化Triad算法

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Artificial Satellites-Journal of Planetary Geodesy Pub Date : 2017-09-26 DOI: 10.1515/arsa-2017-0005

Xiaoning Zhu, M. Ma, Defu Cheng, Zhijian Zhou

引用次数: 4