Undergraduate Mathematics Colloquium

Speaker: David Puelz, ’11

Abstract: How does your iPhone’s or TomTom’s GPS work? Why is it sometimes inaccurate? Or better yet, how can we quantify and analyze these inaccuracies? The Global Positioning System (GPS) is a space-based global navigation satellite system that provides reliable location and time information given an unobstructed line of sight to four or more GPS satellites. The configuration of the GPS satellites has evolved to provide the most functional system for the broadest class of users given a limited amount of resources. However, evaluation methods of the current GPS system utilize only four satellites in view, while increasing the number of satellites to determine position will always increase GPS accuracy. In this talk, I’ll develop intuitively meaningful expressions for a GPS performance metric that utilize information from all satellites in view. I’ll also develop explicit expressions for the metric’s first and second derivatives and construct efficient methods for analyzing GPS coverage. All are invited.  Lunch from Iguanas Ranas will be served.

Date:   Friday, April 22
Time:   Noon – 1:00 PM
Place:  Exley 139