The outline of the WPI football field plotted in UTM coordinates convereted from the recorded GPS data

Over the past few weeks, we have been experimenting with GPS data in preparation for the IGVC Navigation Challenge. As part of our research, we recently went out to the football field at WPI and took our own GPS data using a Sokkia Axis Differential GPS receiver. We took approximately 15 minutes worth of stationary data from the center of the football field in order to determine the errors and drift in the returned GPS latitude and longitude data. We also took dynamic data by walking around the perimeter of the football field three times. The latitude and longitude information that we collected was transferred into UTM Easting and Northing coordinates and was used to plot our locations on a global (x,y) coordinate system. This conversion from latitude and longitude to Cartesian coordinates is one of the first steps in our mapping process that will eventually be used by our robot to determine its current position and successfully plan for its next move.

Ben Roy and Dan Sacco (left) and Justin Barrett (center) out in the frigid Worcester winter gathering DGPS data

The DGPS system, complete with antenna, receiver, and laptop. The receiver streams NMEA formatted data to the laptop through an RS-232 connection