Here the Multipath Phenomenon Is Present
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RReevviiissttaa ddee GGeeooddeezziiiee,, CCaarrttooggrraaffiiiee șșiii CCaaddaassttrruu JJoouurrnnaall ooff GGeeooddeessyy,, CCaarrttooggrraapphhyy aanndd CCaaddaassttrree NNoo.. 1100 Bucharest 2019 ISSN: 1454-1408 Revista de Geodezie, Cartografie şi Cadastru Journal of Geodesy, Cartography and Cadastre No. 10 Bucureşti 2019 ISSN: 1454-1408 Journal of Geodesy, Cartography and Cadastre - ISSN: 1454-1408 Editorial Board Prof. PhD. Habil. Eng. Ana-Cornelia BADEA - President Assoc. Prof. PhD. Eng. Adrian SAVU - Editor in chief Headings coordinators Assoc. Prof. PhD. Eng. Caius DIDULESCU Assoc. Prof. PhD. Eng. Octavian BĂDESCU PhD. Ioan STOIAN PhD. Vasile NACU Online Editor Assoc. Prof. PhD. Eng. Aurel Cătălin Florentin NEGRILĂ Editorial secretary Assist. Prof. PhD. Paul DUMITRU Scientific Committee Prof. PhD. Eng. Petre Iuliu DRAGOMIR Prof. PhD. Eng. Dumitru ONOSE Prof. PhD. Eng. Iohan NEUNER Prof. PhD. Eng. Constantin COȘARCĂ Prof. PhD. Habil. Eng. Gheorghe BADEA Prof. PhD. Habil. Eng. Carmen GRECEA Prof. PhD. Habil. Eng. Sorin HERBAN Prof. PhD. Eng. Maricel PALAMARIU Prof. PhD. Eng. Cornel PĂUNESCU Prof. PhD. Eng. Constantin BOFU Assoc. Prof. PhD. Eng. Livia NISTOR Assoc. Prof. PhD. Eng. Constantin CHIRILĂ Journal of Geodesy, Cartography and Cadastre - ISSN: 1454-1408 * The author(s) of each article is/are solely responsible for the content. Table of Contents Improving GNSS Position Accuracy in Urban areas by using Multi-GNSS Technology Andreea Mihailescu, Iohan Neuner …………………………………………………………………… 1 Determination of a new gravimetric quasigeoid for Romania Neculai Avramiuc, Cătălin Erhan, Ileana Spiroiu, Radu-Dan-Nicolae Crişan, Miluţă Flueraş …….… 7 Level of Georeferencing (LoGeoRef) using IFC for BIM Clemen, Christian and Görne, Hendrik ………………………………………………………………. 15 Semantic Enrichment of the Geometric Elements of Historical Buildings in the Digital Model Daniela Paula Safta, Iohan Neuner …………………………………………………………………… 21 Possibilities for building monitoring, using terrestrial radar interferometry Aurel Sărăcin, Aurel Florentin Cătălin Negrilă, Tudorel Silviu Clinci ………………………………. 27 A contribution to variance analysis of 3D-displacement extracted from GB-SAR measurements Aiham Hassan, Jinjun Xu, Cheng Xing, Volker Schwieger ………………………………………….. 35 Bicentennial of the Superior School of Land Surveying Engineering in the National Language from Wallachia. Remember: Gheorghe Lazăr Gheorghe Nistor, Cristian Onu, Gabriel Săndulache …………………………………………………. 43 Analysing Solar Radiation in Suceava Andreea Mihăilescu, Ana Cornelia-Badea ……………………………………………………………. 49 Monitoring the deformation of an industrial tank in the discharge and filling process Constantin Coșarcă, Aurel Sărăcin, Adrian Savu, Aurel Florentin Cătălin Negrilă ………………….. 55 Journal of Geodesy, Cartography and Cadastre - ISSN: 1454-1408 Improving GNSS Position Accuracy in Urban areas by using Multi-GNSS Technology Andreea Mihailescu1 Iohan Neuner2 Received: September 2018 / Accepted: Octomber 2018 / Published: March 2019 © Journal of Geodesy, Cartography and Cadastre Abstract 1. Introduction The different global systems have been designed to be compatible. According to the definition of the US space- The coexistence of the four GNSS (GPS, Glonass, Galileo, based position, navigation, and time policy, compatibility BeiDou) will either result in an alternative use or in a refers to the ability of two services to be used separately or combination of the services and signals to gain a combined together without interfering with each individual service or solution. An increasing number of systems and signals will signal[1]. With advent of new global systems in full provide an increasing number of observations. Using two operational capability (Glonass, Galileo, BeiDou) offers the systems for position determination will almost double the ability to improve positioning accuracy by using a combined number of navigation satellites and, thus, double the number positioning method. The aim of the paper is to present the of observations for position computation. Although common manner in which data from several satellite systems can be reference systems would have facilitated the used concurrently and to emphasize the necessity of interoperability, the systems have been intentionally adopting a combined GNSS-based solution in difficult designed to use different reference frames, in order to avoid environments where the multipath phenomenon is present. common mode failures and, thus, to increase the integrity of The precision obtained using Static Precise Point combined solutions [1]. The upcoming European Navigation Positioning (static - PPP) was analyzed. With an increasing Satellite System Galileo and the enhanced GPS with new number of satellites the DOP (Dilution of Precision) values frequencies and observation types, especially the possibility decrease, and, consequently, the position accuracy increases. to track frequencies on different channels, requires a more It is analysed SNR (Signal-to-noise ratio) in order to flexible and more detailed definition of the observation quantify the signal power of the received signal. Carrier-to- codes [2]. In the release version of RINEX 3.03 it is noise ratio below 34 dbHz characterize weak signal. emphasized how to deal with different satellite systems. The Multi-GNSS Experiment (MGEX) has been set-up by the Keywords IGS to track, collate and analyze all available GNSS signals. Multi-GNSS, Galileo, BeiDou, PPP, SNR, DOP, multipath This includes signals from the BeiDou, Galileo, QZSS, and NAVIC systems, as well as from modernized GPS and Glonass satellites and any space-based augmentation system (SBAS) of interest. Analysis centers characterize new satellites and signals, compare equipment performance and further develop processing software capable of handling multiple GNSS observation data. The IGS product portfolio will continuously be extended to cover precise ephemeris 1 phD student.eng. Andreea Mihailescu data and bias information for all constellations. Over a Department of Topography and Cadastre/Faculty of Geodesy/ period of four years, a global network of multi-GNSS Technical University of Civil Engineering Bucharest/ stations has been established and integrated with the existing Address: Bd. Lacul Tei nr. 122, Sector 2, Bucharest network of GPS/GLONASS reference stations. In parallel, E-mail:[email protected] 2 Coordinator Prof. PhD.Eng. Iohan Neuner orbit and clock products for most new constelaltions are Department of Topography and Cadastre/Faculty of Geodesy/ generated on a routine basis. It has therefore been decided in Technical University of Civil Engineering Bucharest/ early 2016 to terminate the experimental phase of MGEX Address: Bd. Lacul Tei nr. 122, Sector 2, Bucharest and to pursue the IGS multi-GNSS activities as a pilot E-mail:[email protected] project. New contributions may cover data, products and analyses of all global and regional navigation satellite systems, but should complement existing MGEX capabilities and avoid redundancy. Specific areas of interest include support of NAVIC, 3rd generation BeiDou satellite - 1 - Journal of Geodesy, Cartography and Cadastre - ISSN: 1454-1408 signals, the combination and validation of multi-GNSS orbit effect due to the circular polarization of the electromagnetic and clock 푗 푗 푗 signal; 퐵퐶 – the carrier phase ambiguity term; ℳ퐶 , 푚퐶 – products, the characterization of the GNSS space segment represents the effect of multipath depending on the code (radiation pressure modeling, antenna calibrations, etc.), and 푗 푗 type and frequency; 휀 , 휖 – denotes the receiver noise. the generation of real-time multi-GNSS products. [3] 퐶 퐶 If the processing option ʺTroposphere Correctionʺ is set to At international level, it is therefore necessary to adopt a ʺEstimate ZTD+Gradʺ, a more precise troposphere model is multi-GNSS positioning solution in urban areas or in applied with strict mapping functions as: obstructed sites. The precision obtained using Static multi- 푠 푠 푠 푠 GNSS Precise Point Positioning was analyzed. An important 푚(퐸푙푟) = 푚푊(퐸푙푟)[1 + 푐표푡퐸푙푟(퐺푁,푟푐표푠퐴푧푟 + 푠 objective of the paper is to analyze how multi-GNSS 퐺퐸,푟푠푛퐴푧푟 )] technology contributes in improving Dilution of Precision (5) s s s (DOP). In the study, a signal analysis is performed on the Tr = mH(Elr)ZH,r + m(Elr)(ZT,r − ZH,r main frequencies, available satellite systems in order to (6) analyze the signal-to-noise ratio (SNR) and the multipath Where: phenomenon. So the satellites that do not give good results - ZT,r − tropospheric zenith total delay (m) can be eliminated. - ZH,r − tropospheric zenith hydro‐static delay (m) - mH(El) − hydro‐static mapping function 2. Precise Modelling Terms for multi-GNSS - mW(El) −wet mapping function PPP Phase wind-up effect affects only the carrier phase measurements, it is due to the electromagnetic nature of circularly polarized waves. This correction is required for The PPP technique (Precise Point Positioning) allows high accuracy positioning such as PPP and is modelled as centimetre-level (or even milimetre-level) accuracy to be follows: achieved for static positioning. This high accuracy requires accurate measurement modelling, where all model terms 푇 푇 푇 푇 퐸푟 = (푒푟,푥, 푒푟,푦, 푒푟,푧) such as: precise satellite orbits and clocks, atmospheric 푠 푠푇 푠푇 푠푇 푇 effects – ionospheric refraction and the tropospheric 퐸 = (푒푥 , 푒푦 , 푒푧 ) refraction – antenna biases and orientation, earth 푠 푠 푠 푠 푠 푠 푠 deformation effects must be taken into account. For high-