In the world of GPS tracking devices few things seem to be as illusive as creating the perfect real-time GPS tracking watch. There are plenty examples of watches that act as a data logger, a type of GPS device where position information is gather from the GPS satellites that orbit the earth but stores that information in the device. But there are very few devices that can provide the real-time tracking that most people would want to have in their GPS tracking watch.

In order to understand the difficulty in creating a real-time GPS tracking watch we are going to have to understand a little bit about how GPS devices work in general and how real-time GPS trackers work specifically. First off, all GPS devices work by using a mathematical principle called trilateration. Trilateration takes the known location of 3 or more objects and your distance from those objects to calculate your position.

In the world of GPS, the 3 known locations are going to be 3 of the Global Positioning Satellites that circle the earth constantly. These satellites transmit a specialized signal that contains information used by the GPS receiver to calculate the receiver's distance from that satellite. Once the receiver has enough information from enough satellites it can tell exactly where it is in the world.

GPS tracking watches can very easily integrate this technology onto the wrist of a person. Recent years have seen a massive shrinkage to GPS receivers and this has resulted in more and more "normal" looking GPS watches.

Now that we understand how GPS device get their position information we should take a look at how they transmit this information if they are a real-time tracking device.

Most real-time trackers are going to use cell phone-like technology to transmit its position information to a third party for it to be monitored by you. If you think about it, this makes a lot of sense. The best GPS trackers are already cell phones (since they are almost everywhere and can also use cell towers to sharpen a location even more). They also have the capability to transmit large quantities of information to third parties.

Now, how hard would it be to take everything that you have in a cell phone - both the GPS tracking capabilities and the transmission capabilities - and to put that on the wrist of a person in a fashionable or at least non-obvious way? Pretty hard.

That is why there is still very little presence in the GPS watch market for real-time GPS tracking watches even though the demand for them is reasonably high.