So what's the problem with GPS? Well by now most people are aware of what GPS is and how it works, but lets start of with a brief overview.
GPS systems have a network of more than 50 satellites that cover the globe and enable the GPS system to work. In order to locate the position of a GPS signal, at least three satellites signals have to be received by the GPS tracker. With this information it can triangulate your position and show you where you are.
Now, the accuracy of any GPS unit is dependant on the information received from these satellites. This includes a time stamp. If the time in your GPS tracker is off it can impact the accuracy of the positioning information. However, most units built today take in to account timing inaccuracies so they shouldn't materially affect your position. The main source of inaccurate information comes from atmospheric conditions. When the satellites signals pass through the atmosphere to the GPS tracker, it can encounter conditions that can speed it up or slow it down, thus affecting the time and the calculations that are given.
Inaccuracies can also occur when a signal hits barriers such as skyscrapers, mountains, or other such terrain. This could cause distortions that are similar to those that are caused by atmospheric conditions. What does this mean to you. Well, in built up areas such as large cities, or even in heavily wooded urban areas, the signal could be weakened. If you have car GPS navigation systems with an external aerial you may not find any problems. However, hand held gps systems may struggle due to their small built-in aerials.
Unfortunately, these possible problems are generally unavoidable with GPS systems. However, for most uses these problems will not give you too much bother. Overall, 99% of the time you will have no problems with your GPS.
