Centre de documentation
scientifique

GNSS antenna orientation based on modification of received signal strengths / David Eugen Grimm (2012)  

Public Titre : GNSS antenna orientation based on modification of received signal strengths Type de document : Thèse/HDR Auteurs : David Eugen Grimm, Auteur Editeur : Zurich : Schweizerischen Geodatischen Kommission / Commission Géodésique Suisse Année de publication : 2012 Collection : Geodätisch-Geophysikalische Arbeiten in der Schweiz, ISSN 0257-1722 num. 88 Importance : 148 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-3-908440-33-8 Note générale : Bibliographie Doctoral thesis Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] antenne GNSS [Termes IGN] détection du signal [Termes IGN] orientation [Termes IGN] signal GNSS Index. décimale : 30.70 Navigation et positionnement Résumé : (Editeur) This work presents a concept to determine the orientation of a single GNSS antenna. When the orientation of the antenna is known, the presented approach can also be used for detection of multipath and reflected signals as well as spoofing signals. The orientation of the antenna is calculated using the direction of arrival (DOA) of the satellites' signals. Because the DOAs of the satellites' signals are not detectable with a standard GNSS antenna, the directional antenna pattern of the ntenna used is modified. The antenna pattern is modified by partially covering the antenna with a material that attenuates the signals in the band spectrum of GNSS. The attenuating material is rotated above the antenna, thereby influencing the received signal strength of the different satel lites. The signal strength is indicated by the carrier-to-noise density C/N0. Analysing the C/N0 of different satellites allows determining the DOA of each satellite's signal in relation to the antenna. Knowing the satellites' positions from the broadcast ephemerides and the antenna position allows calculation of the antenna orientation as well as the theoretically expected DOAs. Based on the instant approach, the real DOA of each satellite's signal is determined. By comparing the expected DOAs with the real DOAs, multipath and reflected signals as well as spoofing signals are determinable. Excluding these signals from the position and orientation calculation can remove systematic biases and, therefore, improve the accuracy. Knowledge of the orientation completes the positioning information and is necessary for navigation applications. For precise GNSS measurements, the orientation of the antenna must be known to implement correction models for the antenna phase centre offset (PCO) and phase centre variation (PCV). Under optimal conditions, orientation information with an uncertainty of 5 degrees is achievable after a 2-minute measurement while an orientation with an uncertainty below 1 degree is achievable by measuring for several hours. Under poor condition s, an uncertainty of 5 degrees is achievable as well; however, because of systematic influences, the uncertainty will not improve significantly over a longer measuring time. A comparison of the obtained orientation value to a reference value verifies the correctness of the concept. Note de contenu : 1 Introduction 1.1 Global Navigation Satellite Systems (GNSS). 1.2 Why Orientation? 1.3 Determination of Orientation by GNSS 1.4 Introducing the Term Orientation 1.5 North Direction and Terrestrial Reference System. 1.6 Outline of this Thesis. 2 State of the Art in GNSS Orientation Determination. 2.1 System Types 2.2 Description of the Effects and Concepts Used 2.3 Overview of Existing Methods and Systems 2.4 Chapter Conclusion 3 GNSS Antennas and Signals 3.1 Antennas 3.2 Antenna Fields 3.3 Antenna Characteristics 3.4 GNSS Antenna Types 3.5 Geodetic GNSS Antennas 3.6 GNSS Signals 3.7 Chapter Conclusion 4 Mathematical Models for Satellite Orbits 4.1 Broadcast Ephemerides, Almanac, and GPS Time 4.2 Orbit Calculation 4.3 Satellite Motion 4.4 Chapter Conclusion 5 Orientation Finding with NORDIS 5.1 Required Accuracy 5.2 Measurement Concept of NORDIS 5.3 Measuring System 5.4 Experimental Setup 5.5 Chapter Conclusion 6 Orientation Calculation 6.1 Periodic Model 6.2 Correlation Approach 6.3 Chapter Conclusion 7 Verification of the Results 7.1 Dependency of the Measuring Duration on the Orientation Uncertainty. 7.2 Verification of the Components 7.3 Chapter Conclusion 8 Conclusion and Outlook 8.1 Conclusion 8.2 Possible Use Cases 8.3 Possible Improvements of NORDIS 8.4 Limitations of NORDIS Numéro de notice : 15702 Affiliation des auteurs : non IGN Autre URL associée : URL ETH Zurich Thématique : POSITIONNEMENT Nature : Thèse étrangère DOI : 10.3929/ethz-a-007597299 En ligne : https://www.sgc.ethz.ch/sgc-volumes/sgk-88.pdf Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=62765

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
15702-01	30.70	Livre	Centre de documentation	Géodésie	Disponible