scholarly journals DIFFERENCES BETWEEN 2009 AND 2016 REVISIONS BASED ON COORDINATES IN GDM2000

2021 ◽  
Vol 6 (24) ◽  
pp. 161-173
Author(s):  
Nur Adilla Zulkifli ◽  
Ami Hassan Md Din ◽  
Wan Anom Wan Aris ◽  
Zheng Yong Chien
Keyword(s):  
Terrestrial Reference Frame ◽  
Peninsular Malaysia ◽  
Global Navigation Satellite Systems ◽  
Ellipsoidal Height ◽  
Positional Accuracy ◽  
Tectonic Plate ◽  
Satellite Systems ◽  
Datum Transformation ◽  
Gnss Network ◽  
Global Navigation Satellite

The Geocentric Datum of Malaysia (GDM200) is realised with respect to International Terrestrial Reference Frame (ITRF) 2000 at epoch 2nd January 2000. In comparison with the 2000 frame, ITRF2014 has significant improvement in terms of its definition and realisation. Moreover, several great earthquakes that struck the Indonesian region for the past decades have deformed the tectonic plate, resulting in a shifted GDM2000. These earthquakes, followed by post-seismic activities, has caused GDM2000 to become obsolete. Following that, the Department of Survey and Mapping Malaysia (DSMM) has taken the initiative to revise the coordinate of Malaysia Real-Time Kinematic Global Navigation Satellite Systems (GNSS) Network (MyRTKnet) stations in GDM2000 into a new set of coordinates. Therefore, this paper presents an effort to analyse the differences between coordinates in GDM2000 based on 2009 and 2016 revisions. In order to measure the discrepancy, forty-seven (47) MyRTKnet stations in Peninsular Malaysia were chosen to estimate the differences between the two (2) revisions. The coordinates obtained from MyRTKnet stations were then projected into Rectified Skewed Orthomorphic (RSO) coordinate system to compute the differences in horizontal position and ellipsoidal height. The finding showed that the discrepancy ranges from 0.8 to 11.8 cm, with the smallest values at SETI station and the biggest value at KRAI station. Meanwhile, for the differences in ellipsoidal height, LIPI station has the biggest value of 8.1 cm, followed by the smallest value of 0.4 cm at SETI station. In conclusion, as the differences in revision gave impact on the changes of coordinates of MyRTKnet stations in Peninsular Malaysia, the frequent revision of GDM2000 should also consider the latest frame to give better positional accuracy, and a proper datum transformation (ITRF2014 to ITRF2000) need to be implemented for mapping purposes.

The Contribution of LARES to Global Climate Change Studies With Geodetic Satellites

2015 ◽  
Author(s):  
Giampiero Sindoni ◽  
Claudio Paris ◽  
Cristian Vendittozzi ◽  
Erricos C. Pavlis ◽  
Ignazio Ciufolini ◽  
...  
Keyword(s):  
Reference Frame ◽  
Earth Science ◽  
Global Climate ◽  
Temporal Variations ◽  
Terrestrial Reference Frame ◽  
Global Navigation Satellite Systems ◽  
Satellite Systems ◽  
Long Baseline ◽  
Geophysical Processes ◽  
Global Navigation Satellite

Satellite Laser Ranging (SLR) makes an important contribution to Earth science providing the most accurate measurement of the long-wavelength components of Earth’s gravity field, including their temporal variations. Furthermore, SLR data along with those from the other three geometric space techniques, Very Long Baseline Interferometry (VLBI), Global Navigation Satellite Systems (GNSS) and DORIS, generate and maintain the International Terrestrial Reference Frame (ITRF) that is used as a reference by all Earth Observing systems and beyond. As a result we obtain accurate station positions and linear velocities, a manifestation of tectonic plate movements important in earthquake studies and in geophysics in general. The “geodetic” satellites used in SLR are passive spheres characterized by very high density, with little else than gravity perturbing their orbits. As a result they define a very stable reference frame, defining primarily and uniquely the origin of the ITRF, and in equal shares, its scale. The ITRF is indeed used as “the” standard to which we can compare regional, GNSS-derived and alternate frames. The melting of global icecaps, ocean and atmospheric circulation, sea-level change, hydrological and internal Earth-mass redistribution are nowadays monitored using satellites. The observations and products of these missions are geolocated and referenced using the ITRF. This allows scientists to splice together records from various missions sometimes several years apart, to generate useful records for monitoring geophysical processes over several decades. The exchange of angular momentum between the atmosphere and solid Earth for example is measured and can be exploited for monitoring global change. LARES, an Italian Space Agency (ASI) satellite, is the latest geodetic satellite placed in orbit. Its main contribution is in the area of geodesy and the definition of the ITRF in particular and this presentation will discuss the improvements it will make in the aforementioned areas.

scholarly journals Node-Based Optimization of GNSS Tomography with a Minimum Bounding Box Algorithm

2020 ◽  
Vol 12 (17) ◽  
pp. 2744
Author(s):  
Nan Ding ◽  
Xiangrong Yan ◽  
Shubi Zhang ◽  
Suqin Wu ◽  
Xiaoming Wang ◽  
...  
Keyword(s):  
Global Navigation Satellite Systems ◽  
Radiosonde Data ◽  
New Approach ◽  
Satellite Systems ◽  
Bounding Box ◽  
Percent Improvement ◽  
The Common ◽  
Gnss Network ◽  
Global Navigation Satellite ◽  
Mean Square Errors

Global Navigation Satellite Systems (GNSS) tomography plays an important role in the monitoring and tracking of the tropospheric water vapor. In this study, a new approach for improving the node-based GNSS tomography is proposed, which makes a trade-off between the real observed region and the complexity of the discretization of the tomographic region. To obtain dynamically the approximate observed region, the convex hull algorithm and minimum bounding box algorithm are used at each tomographic epoch. This new approach can dynamically define the tomographic model for all types of study areas based on the GNSS data. The performance of the new approach is tested by comparing it against the common node-based GNSS tomographic approach. Test data in May 2015 are obtained from the Hong Kong GNSS network to build the tomographic models and the radiosonde data as a reference are used for validating the quality of the new approach. The experimental results show that the root-mean-square errors of the new approach, in most cases, have a 38 percent improvement and the values of standard deviation reduce to over 43 percent compared with the common approach. The results indicate that the new approach is applicable to the node-based GNSS tomography.

scholarly journals Linear and Nonlinear Deformation Effects in the Permanent GNSS Network of Cyprus

Sensors ◽  
2020 ◽  
Vol 20 (6) ◽  
pp. 1768
Author(s):  
Chris Danezis ◽  
Miltiadis Chatzinikos ◽  
Christopher Kotsakis
Keyword(s):  
Crustal Deformation ◽  
Global Navigation Satellite Systems ◽  
Satellite Systems ◽  
Time Period ◽  
Position Time Series ◽  
Gnss Receivers ◽  
Linear And Nonlinear ◽  
Gnss Network ◽  
Global Navigation Satellite ◽  
Gnss Data

Permanent Global Navigation Satellite Systems (GNSS) reference stations are well established as a powerful tool for the estimation of deformation induced by man-made or physical processes. GNSS sensors are successfully used to determine positions and velocities over a specified time period, with unprecedented accuracy, promoting research in many safety-critical areas, such as geophysics and geo-tectonics, tackling problems that torment traditional equipment and providing deformation products with absolute accuracy. Cyprus, being located at the Mediterranean fault, exhibits a very interesting geodynamic regime, which has yet to be investigated thoroughly. Accordingly, this research revolves around the estimation of crustal deformation in Cyprus using GNSS receivers. CYPOS (CYprus POsitioning System), a network of seven permanent GNSS stations has been operating since 2008, under the responsibility of the Department of Lands and Surveys. The continuous flow of positioning data collected over this network, offers the required information to investigate the behavior of the crustal deformation field of Cyprus using GNSS sensors for the first time. This paper presents the results of a multi-year analysis (11/2011–01/2017) of daily GNSS data and provides inferences of linear and nonlinear deforming signals into the position time series of the network stations. Specifically, 3D station velocities and seasonal periodic displacements are jointly estimated and presented via a data stacking approach with respect to the IGb08 reference frame.

Developing Equatorial Plasma Bubbles Observed by Multi-Instrument at Dawn

2021 ◽  
Author(s):  
Kun Wu ◽  
Jiyao Xu ◽  
Xinan Yue ◽  
Chao Xiong ◽  
Wenbin Wang ◽  
...  
Keyword(s):  
Southern China ◽  
Life Time ◽  
Peak Height ◽  
Global Navigation Satellite Systems ◽  
Satellite Systems ◽  
Plasma Bubbles ◽  
F Region ◽  
Equatorial Plasma Bubbles ◽  
Gnss Network ◽  
Global Navigation Satellite

<p>Previous studies have shown that equatorial plasma bubbles (EPBs) usually occur after sunset, and they usually drift eastward. Observations from an all-sky imager and the Global Navigation Satellite Systems (GNSS) network in southern China showed a special EPB event. Observational results show that the EPBs appeared near dawn and continued to develop after sunrise. They disappeared about one hour after sunrise which the life time of those EPBs exceeds 3 hours. The result provided an evidence that the EPB could develop around sunrise in optical observation. Meanwhile, those observation showed that the EPBs drifted westward, which was different from the usually eastward drifts of EPBs. The simulation from TIE-GCM model suggest that the westward drift of EPBs should be related to the enhanced westward winds at storm time. Besides, increasing in the ionospheric F region peak height was also observed near sunrise. We suggest enhance upward vertical plasma drift during geomagnetic storm plays a major role in triggering the EPBs near sunrise.</p>

scholarly journals A new approach for GNSS tomography from a few GNSS stations

2018 ◽  
Vol 11 (6) ◽  
pp. 3511-3522 ◽  
Author(s):  
Nan Ding ◽  
Shubi Zhang ◽  
Suqin Wu ◽  
Xiaoming Wang ◽  
Allison Kealy ◽  
...  
Keyword(s):  
Water Vapor ◽  
Global Navigation Satellite Systems ◽  
Radiosonde Data ◽  
Network Tomography ◽  
Unknown Parameters ◽  
New Approach ◽  
Satellite Systems ◽  
Gnss Network ◽  
Global Navigation Satellite

Abstract. The determination of the distribution of water vapor in the atmosphere plays an important role in the atmospheric monitoring. Global Navigation Satellite Systems (GNSS) tomography can be used to construct 3-D distribution of water vapor over the field covered by a GNSS network with high temporal and spatial resolutions. In current tomographic approaches, a pre-set fixed rectangular field that roughly covers the area of the distribution of the GNSS signals on the top plane of the tomographic field is commonly used for all tomographic epochs. Due to too many unknown parameters needing to be estimated, the accuracy of the tomographic solution degrades. Another issue of these approaches is their unsuitability for GNSS networks with a low number of stations, as the shape of the field covered by the GNSS signals is, in fact, roughly that of an upside-down cone rather than the rectangular cube as the pre-set. In this study, a new approach for determination of tomographic fields fitting the real distribution of GNSS signals on different tomographic planes at different tomographic epochs and also for discretization of the tomographic fields based on the perimeter of the tomographic boundary on the plane and meshing techniques is proposed. The new approach was tested using three stations from the Hong Kong GNSS network and validated by comparing the tomographic results against radiosonde data from King's Park Meteorological Station (HKKP) during the one month period of May 2015. Results indicated that the new approach is feasible for a three-station GNSS network tomography. This is significant due to the fact that the conventional approaches cannot even solve a network tomography from a few stations.

scholarly journals A new approach for GNSS tomography from a few GNSS stations

2018 ◽  
Author(s):  
Nan Ding ◽  
Shubi Zhang ◽  
Suqin Wu ◽  
Xiaoming Wang ◽  
Allison Kealy ◽  
...  
Keyword(s):  
Water Vapor ◽  
Global Navigation Satellite Systems ◽  
Radiosonde Data ◽  
Network Tomography ◽  
Unknown Parameters ◽  
New Approach ◽  
Satellite Systems ◽  
Gnss Network ◽  
Global Navigation Satellite

Abstract. The determination of the distribution of water vapor in the atmosphere plays an important role in the atmospheric monitoring. Global Navigation Satellite Systems (GNSS) tomography can be used to construct 3D distribution of water vapor over the field covered by a GNSS network with high temporal and spatial resolutions. In current tomographic approaches, a pre-set fixed rectangular field that roughly covers the area of the distribution of the GNSS signals on the top plane of the tomographic field is commonly used for all tomographic epochs. Due to too many unknown parameters needing to be estimated, the accuracy of the tomographic solution degrades. Another issue of these approaches is their unsuitability for GNSS networks with a few stations as the shape of the field covered by the GNSS signals is in fact roughly an upside-down cone rather than the rectangular cube as the pre-set. In this study, a new approach for determination of tomographic fields fitting the real distribution of GNSS signals on different tomographic planes at different tomographic epochs and also for discretization of the tomographic fields based on the perimeter of the tomographic boundary on the plane and meshing techniques is proposed. The new approach was tested using three stations from the Hong Kong GNSS network and validated by comparing the tomographic results against radiosonde data from King's Park Meteorological Station (HKKP) during the one month period of May, 2015. Results indicated that the new approach is feasible for a three-station GNSS network tomography. This is significant due to the fact that the conventional approaches cannot even solve a few stations network tomography.

scholarly journals THE HANDHELD MOBILE LASER SCANNERS AS A TOOL FOR ACCURATE POSITIONING UNDER FOREST CANOPY

2020 ◽  
Vol XLIII-B1-2020 ◽  
pp. 211-218 ◽  
Author(s):  
J. Chudá ◽  
M. Hunčaga ◽  
J. Tuček ◽  
M. Mokroš
Keyword(s):  
Forest Canopy ◽  
Sustainable Forest Management ◽  
Environmental Data ◽  
Global Navigation Satellite Systems ◽  
Forest Environment ◽  
Positional Accuracy ◽  
Satellite Systems ◽  
Localization And Mapping ◽  
Laser Scanners ◽  
Global Navigation Satellite

Abstract. Nowadays it is important to shift positional accuracy of object measurements under the forest canopy closer to the accuracy standards for land surveys due to the requirements in the field of ecosystem protection, sustainable forest management, property relations, and land register. Simultaneously, it is desirable to use the technology of environmental data acquisition which is not time consuming and cost demanding. Global Navigation Satellite Systems (GNSS) are the most used for positioning today. However, the usefulness and also the accuracy of the measurements with this technology depend on various factors (the strength of the GNSS signal, the geometric position of satellites, the multipath effect etc.). Based on the above mentioned facts, the usability of technology independent of GNSS indicates an ideal solution for positioning under the forest canopy. Several studies have studied the usability of Handheld Mobile Laser Scanners (HMLS) in complex environment. The goal of this paper was to verify a new data collection approach (HMLS with Simultaneous Localization and Mapping (SLAM) technology) for the forest environment practice. The main objective of our study was to reach a precision which complies with the accuracy standards for land surveys. The RMSE of derived positions from point cloud, produced by SLAM devices were 25.3 cm and 28.4 cm, for ZEB REVO and ZEB HORIZON, the handheld mobile laser SLAM scanners used in this study. ZEB HORIZON achieved twice as big accuracy of diameter of breast height (DBH) estimation as ZEB REVO.

scholarly journals Application of Robust Estimation Method for Establishing 3D Combined Terrestrial and GNSS Network: A case of a Quarry in Lang Son, Vietnam

2020 ◽  
Vol 1 (2) ◽  
Author(s):  
Luu ANH TUAN ◽  
Hoang NGOC HA ◽  
La PHU HIEN ◽  
Pham VAN CHUNG
Keyword(s):  
Data Processing ◽  
Robust Estimation ◽  
Weighting Function ◽  
Estimation Method ◽  
Geodetic Network ◽  
Global Navigation Satellite Systems ◽  
Satellite Systems ◽  
Gnss Network ◽  
Global Navigation Satellite ◽  
Mine Surveying

Recently, in Vietnam, the detection of geodetic measurements that contain rough errors as well as such data processing method has been considered as a key step in geodetic data processing, especially for large geodetic networks with many different types of measurements like 3D - Global Navigation Satellite Systems (GNSS) network. On the other hand, mines in Vietnam often have complex terrains, so it is necessary to apply modern and flexible surveying methods in combination with ground and space measurements to build 3D coordinates control networks for management and exploitation to ensure sustainable development. Therefore, this research developed a Robust estimation method based on empirical weighting function for establishing 3D geodetic network combining terrestrial observation and GNSS vectors. The experiment on processing the combined network in Lang Son limestone quarry, Vietnam showed that the proposed method could be an effective solution for processing 3D terrestrial – GNSS geodetic network for mine surveying in Vietnam.

scholarly journals GEOSPATIAL DATA QUALITY OF THE SERVIR CORS NETWORK

2015 ◽  
Vol II-3/W5 ◽  
pp. 285-290 ◽  
Author(s):  
J. Santos ◽  
R. Teodoro ◽  
N. Mira ◽  
V. B. Mendes
Keyword(s):  
Quality Control ◽  
Geospatial Data ◽  
Global Navigation Satellite Systems ◽  
Positional Accuracy ◽  
Worst Case ◽  
Static Mode ◽  
Satellite Systems ◽  
Gnss Positioning ◽  
Global Navigation Satellite

The SERVIR Continuous Operation Reference Stations (CORS) network was implemented in 2006 to facilitate land surveying with Global Navigation Satellite Systems (GNSS) positioning techniques. Nowadays, the network covers all Portuguese mainland. The SERVIR data is provided to many users, such as surveyors, universities (for education and research purposes) and companies that deal with geographic information. By middle 2012, there was a significant change in the network accessing paradigm, the most important of all being the increase in the responsibility of managing the network to guarantee a permanent availability and the highest quality of the geospatial data. In addition, the software that is used to manage the network and to compute the differential corrections was replaced by a new software package. These facts were decisive to perform the quality control of the SERVIR network and evaluate positional accuracy. In order to perform such quality control, a significant number of geodetic monuments spread throughout the country were chosen. Some of these monuments are located in the worst location regarding the network geometry in order to evaluate the accuracy of positions for the worst case scenarios. Data collection was carried out using different GNSS positioning modes and were compared against the benchmark positions that were determined using data acquired in static mode in 3-hour sessions. We conclude the geospatial data calculated and provided to the users community by the network is, within the surveying purposes, accurate, precise and fits the needs of those users.

scholarly journals A Terrestrial Reference Frame (TRF), coordinates and velocities for South American stations: contributions to Central Andes geodynamics

2009 ◽  
Vol 22 ◽  
pp. 181-184 ◽  
Author(s):  
M. V. Mackern ◽  
M. L. Mateo ◽  
A. M. Robin ◽  
A. V. Calori
Keyword(s):  
Reference Frame ◽  
Central Andes ◽  
Terrestrial Reference Frame ◽  
Global Navigation Satellite Systems ◽  
South American ◽  
Good Precision ◽  
Positioning Systems ◽  
Satellite Systems ◽  
Satellite Positioning ◽  
Global Navigation Satellite

Abstract. Satellite positioning systems allow the fixing of the location of a point on the Earth's surface with very good precision and accuracy. To do this, however, it is necessary to determine the point coordinates taking account the reference system and the movements that affect them because of tectonic plate movements. These reference systems are materialized by a significant number of continuous measurement stations in South America. In SIRGAS (Sistema de Referencia Geocéntrico para las Américas), there are four Analysis Centers that process the data collected from satellites of the Global Navigation Satellite Systems (GNSS), with the primary purpose to maintain the international terrestrial reference frame through calculation of the coordinates and velocities of the continuous GNSS stations of the SIRGAS-CON Network. In this work, we demonstrate the quality of the solutions from CIMA, one of the SIRGAS official processing centers operating in Mendoza, Argentina, in comparison with other South American processing centers. The importance of precise calculations of coordinates and velocities in a global frame is also shown. Finally, we give estimations of velocities from stations located within deformation zones in the Central Andes.

Sign in / Sign up

Export Citation Format

Share Document