For those not familiar with APRS, it stands for the [Automatic Packet Reporting System] and is used by amateur radio operators for applications like transferring messages and location data over RF networks and the internet. The internet connection is where an iGate comes into play. An iGate is used to connect an APRS RF network to the internet, so that many isolated RF APRS networks can communicate worldwide. Furthermore this software can be configured as a “SatGate”, which like an APRS iGate will take messages from APRS satellite’s and route them over the internet.
For example, you could have an amateur radio vehicle continually transmitting it’s location via RF to an APRS iGate. The vehicles position can then be viewed online on an APRS aggregation site like aprs.fi, or it could be re-transmitted over RF elsewhere in the world.
An iGate is usually accomplished by using a ham radio tuned to the local APRS frequency (or sat frequency) and then special PC software is configured to gate the messages. However, with the release of PyPacket the amount of work and cost required to setup an iGate has been cut drastically.