Vertical Component of Satellite Navigation Systems

Jacek Januszewski

doi:10.2478/v10018-011-0002-6

Abstract

Vertical Component of Satellite Navigation SystemsThe altitude is one of four coordinates of the user's position obtained from Satellite Navigation System (SNS) measurements. The distributions (in per cent) of VDOP coefficient value for different constellations of three SNS - GPS, GLONASS and Galileo - for different masking elevation angles for different user's latitudes are presented in the paper. The results of the measurements of GPS position and vertical accuracy in mode "3D" and position accuracy in mode "2D" for different GPS receivers and different receiver's antenna heights are demonstrated also. Additionally the use of vertical component of SNS in maritime navigation like the determination highly accurate sea-floor depths is presented.

Highlights

The first calculations concerning VDOP coefficient value for different GPS constellations and nominal Galileo constellation and the measurements of GPS vertical accuracy in modes 3D and 2D were realized by the author in 2005 (Januszewski 2005a, 2005b)
27 satellites) and the measurements of GPS vertical accuracy in modes 3D and 2D were realized by the author in 2005 (Januszewski 2005a, 2005b)
GPS system consists of 31 satellites, the number of GLONASS atellites with status operational is 20 and at the end of this year the Russian system will have Full Operational

Summary

INTRODUCTION

The first calculations concerning VDOP coefficient value for different GPS constellations 27 satellites) and the measurements of GPS vertical accuracy in modes 3D and 2D were realized by the author in 2005 (Januszewski 2005a, 2005b). Capability (FOC) again, the Galileo system is already under construction, the additional calculations and measurements are necessary. As the nominal vitality of these satellites is 10 years only, the GPS constellation without these space vehicles must be taken in to account. The Standard Positioning Service (SPS) uses C/A code on the L1 signal only. The SPS performance refers to the signal in space (SIS). In SPS based on a 95% probability level and SIS only GPS system provides a global coverage predictable positioning accuracy of 9 m (95%) horizontally and 15 m (95%) vertically (www.navcen.uscg.gov)

VERTICAL POSITION ACCURACY

TEST METHOD

Findings

THE USE OF VERTICAL COMPONENT OF SNS IN MARITIME NAVIGATION