I hope I can explain: Our company uses GPS along with WiFi/GPRS to send Lat/Long values to our server which then is accessed by golf courses to monitor the position of the carts. This also allows us to collect the Lat/Long values and display a history track of where the cart traveled on the course. The issue is during the morning, local time at the course, if a cart follows the cart path, the track is on the path or very close to it. As the day progresses the tracks will drift to the north. These units are installed throughout the world, we see this drift in Hawaii, Japan, Middle East and Austalia, exept the drift is south there. Courses in the US, Canada, Mexico, Europe and South Africa do not exhibit this or if there is a shift it is well within our expected accuracies that it is not an issue. We use the U-blox 5 GPS module, which uses SBAS corrections, but I am not sure if the firmware/software in the module is out of date to account for any changes in the SBAS configuration. I am trying to find that information from U-Blox at this time. Basically trying every avenue I can find to get ideas as to why this is happening. I have attached a couple of pictures depicting my problem. Thanks for listening Mark
