Name: Korakot Saelim
Title: Effect of Urban Multipath and Spatial Distribution of Cellular Network on Smartphone and GNSS Devices
An increasing in navigation satellite systems leads to the ability of identifying location for GNSS devices. Similarly, Smartphone devices have grown continuously also. However, some areas have limitation from the effect of receiving satellites and cellular network such as multipath and spatial distribution of cellular network. By multipath, it is the effect that reveivers cannot directly measure pseudorange from satellite because reflection from surrounding objects. Thus, the effect from this cause leads to determine inaccurate location. To consider surrounding environment, sky view factor is an index to observe characteristic of visibility from obscuring of objects.
This study aim to evaluate the effect of urban multipath from sky view factor and spatial distribution of cellular network for reliable positioning. In this study, the sky view factor as representing the characteristics of visibility was estimated from the sky view image of fish eye camera. Subsequently, the reliable positioning of six different GNSS and Smartphone devices were evaluated the relationship with the characteristics of visibility in the study area. The result show that GNSS devices require skyview factor 0.46 to expect the reliable positioning at excellent level.
Additionally, the effects of spatial distribution of cellular network on the reliable positioning of Smartphone. The result shows that, the distance between device and connected cellular tower have affected to initialing and identifying location on cellular network. The location can show the reliable positioning at moderate level or about 50%. However, the main problem is about 95%, device cannot determine location to users.
Finally, the reliable positioning mapping at the Sukhumvit 11 and Sukhumvit 13, Bangkok was developed for each device by using the sky view image from fish eye camera and existent location cellular network. It is found that 60% area were classified as the excellent reliable positioning for GNSS devices and 50% area were classified as the expected reliable positioning for Smartphone devices.