#ogn.
Posts on the Alpisto engineering blog filed under #ogn.
- 01#flybeeper #fanet #ads-l
One radio, two networks: how a FANET vario shares every second with ADS-L
My vario has one radio and two networks to serve. Every second it decides which one to listen to and when to speak, and that choice decides who you see on the map. The numbers from the bench: listen to ADS-L for the whole second and FANET goes to zero; stop listening to ADS-L and FANET comes back 40 to 140 % stronger; cut the ADS-L window from 550 to 300 ms and another maker's transmitter drops from 61 % of its seconds heard to 34 %.
12 min read - 02#flybeeper #fanet #ads-l
Teaching a LoRa vario to hear ADS-L — and finding the time to do it
Every ADS-L receiver takes its clock from GNSS. My vario has no GNSS by design — the position comes from the phone in your harness. So I took the UTC second from the phone too, over Bluetooth, and measured how bad that channel really is. Good enough with room to spare: the share of frames the device caught went from 15 % to between 50 and 100 %.
16 min read - 03#flybeeper #fanet #flarm
FLARM, FANET and ADS-L — where the line actually is
Why I won't ship FLARM on hardware that could technically transmit it, what the licence actually permits, why FANET's adaptive interval matters in a gaggle, why LoRa means FANET can never be the EU conspicuity standard — and why ADS-L is a better bet than it looks.
8 min read