You are here

How Zit Wurk?

How Zit Wurk?
by Gary Woods

As a Realtor there's always a GPS device close by when I'm showing property. Without my GPS I never would be able to find half the houses I'm looking for. So, being the curious sort I thought I'd look at how it works and see if there's a way I can make it better.

To start off with to get us where we want to go there are 30 GPS satellites spinning around the globe above our heads. In order for a GPS device to work it needs a direct line-of-sight connection with at least four of them for a 3D location fix. If you're not connecting via a cell phone or without WiFi it takes about 30 seconds to complete that hookup. This time to liftoff is because your device must learn the satellites' positions and measure the time it takes to receive signals from them.

To speed up the process, if you're using a phone or other cellular device with GPS it receives rough location information from cell towers which enables the phone to more quickly find the correct satellites so you know where you are . Also, since orbital data is stored online your phone is programmed to access it automatically over a Wi-Fi network in places where cellular signal is weak or not available.

When your phone's line-of-sight view of the satellites is obstructed, your cellular provider helps out by giving the device its rough location based on its distance from the cell towers in the area.

If all of these elements, satellites, cell towers and Wi-Fi are in alignment it takes about 1 second to grab your location and send you scurrying off into the hinterland.

If you have any suggestions or questions for me please drop me a note at or see my column on the Internet at or call me at (805) 729-0910

Gary Woods is the Computer Trainer for the Santa Barbara Association of Realtors. And he is a Broker/Associate at Home Realty & Investments, Inc