This brief discussion of PerlAPRS is intended to provide a simple overview. The program provides several additional features intended for real time applications. PerlAPRS is distributed under the GNU licensing agreement. The GPS is truly what makes the system practical. Although the details of the GPS are extremely complex, the basic idea is relatively simple.
Triangulation is used to pinpoint a receiver.
For example, assume you and your friend both have accurate synchronized clocks. With this single test point, you are able to compute your distance from the source. Specifically, you are located in any direction 100 meters from your friend. This scenario is shown in Figure 4A by the multiple dots located on the circumference of the circle. With a second friend, we can further clarify our position.