Simulation of GNSS Availability in Urban Environments Using a Panoramic Image Dataset

Sakpod Tongleamnak,Masahiko Nagai

doi:10.1155/2017/8047158

Abstract

Performance of Global Navigation Satellite System (GNSS) positioning in urban environments is hindered by poor satellite availability because there are many man-made and natural objects in urban environments that obstruct satellite signals. To evaluate the availability of GNSS in cities, this paper presents a software simulation of GNSS availability in urban areas using a panoramic image dataset from Google Street View. Photogrammetric image processing techniques are applied to reconstruct fisheye sky view images and detect signal obstacles. Two comparisons of the results from the simulation and real world observation in Bangkok and Tokyo are also presented and discussed for accuracy assessment.

Highlights

The Global Navigation Satellite System (GNSS) plays a crucial role in providing positioning services for various applications such as navigation and Location Based Services (LBS) [1]
It is known that GNSS positioning availability and accuracy depend largely on the number and geometry of satellites which are visible to a GNSS receiver
The simulation correctly predicted 81.90% of satellite visibilities for these tests. These results indicate that the simulation can use Google Street View to predict GNSS satellites visibility for nearby locations with good accuracy

Summary

Introduction

The Global Navigation Satellite System (GNSS) plays a crucial role in providing positioning services for various applications such as navigation and Location Based Services (LBS) [1]. It is known that GNSS positioning availability and accuracy depend largely on the number and geometry of satellites which are visible to a GNSS receiver Several tools such as Trimble Planner [2] and GNSSRadar [3] have been created to predict the availability and geometry of GNSS satellites at a given location and time. Evaluations of the urban canyon effect are usually conducted directly by measurement with a receiver, which is time-consuming and requires a site visit, and this might not be feasible. Another method is using 3D GIS or 3D city models to simulate the availability of GNSS [4,5,6]. The simulation accuracy is evaluated based on two actual survey experiments conducted in central Bangkok and Tokyo by a vehicle equipped with a GNSS receiver

Methods

Comparison of Simulation Result with Observation Data

25 Average

Findings

Conclusion and Future Works