Weak Signal GPS – An Overview
Among other factors that interfere with a GPS signal is the intersection of two or more signal paths. During this clash of signal paths rising from different satellites, the data may change or get corrupt. Though the placement of satellites is done thoughtfully, it is sometimes natural for the signals to intersect, causing damage to the data.
The aim of GPS satellites is to offer a straight path that carries data to the GPS without any radio signal interference. However, it is not always successful. On the contrary, the problem seldom occurs. The intelligent GNSS receivers inside the GPS devices are capable of detecting erroneous data and stop computing until they start receiving correct data.
Under cases when there is GPS blackout, you can use Dead Reckoning Method or Map Matching. Both methods use the previous data to create navigational information.
Finally, you are made to believe that GPS is not for indoor use. It is true that the GPS signal strength is very weak when you are inside any building but this does not mean that you cannot use the device indoors. The workaround is Re-radiation.
As the ground based GPS device receives the signal, it filters the signal to extract data on: the three planes (X, Y, and Z axis), satellites through which it received the signals, position of each satellite, time stamps of each signal, and the possible redundant clock errors at the satellite's end. Based on all this data, the GPS device filters, boosts, and finds the strongest GPS signal before computing it to offer you with the desired information.
In its endeavor to locate the strongest GPS signal, the GPS device may find that the strongest signal is a very weak signal out of which, it has to extract the data sent by the satellites. Still, the GPS is a technology that won't let you down. Among other methods, WAAS (also called SBAS) is one method to recreate accuracy of GPS.