To analyse the APRS network you are receiving the packets of you have to do more than just capture stations.
Radio Mobile requires more than what is retrieved from APRS.
Radio Mobile only captures a small data set out of the APRS information. This due to the nature of Radio Mobile and how the Radio Mobile network is stuctured. The following information is retrieved from APRS:
Information about the radio parameters are not transmitted through APRS so these have to be verified by the station owner or guessed by you. It can be of help when PHG information is analysed. PHG (Power, Height, Gain) contains:
- Transmit power
- Antenne height
- Antenna gain
- Antenna direction.
Information about the receive sensitivity must be verified or asumed. A educated guess is that a AX25 APRS station has a sensitivity of -115 dBm at a dipole antenna.
When the required units are 'captured' the unit specifications must be specified in 'systems'
If required the captured stations can be split in to networks as required. In the following example 3 networks are configured:
- APRS FTOV, the APRS network, containing all digi's that form the 24/7 stable part.
- APRS QRM, APRS digi's that add to the network on a irregular basis.
- APRS (not displayed), all participating digi's.
Now we can analyse the network.