Kraviator:
Be careful, the Garmin GPS-20A - and the Dynon GPS-2020 - are not approved for use in Australian ADS-B installations as they have not been TSO'd, so do not meet the requirements for a position source. In the U.S., they "meet the performance requirements of the FAR's" which is deemed suitable over there. But it's not here.
I've been going through the CARs and various TSOs for a month trying to find a technicality that means I can use Dynons offering, but without success so far.
Which begs the question; Why is such a unit acceptable in the USA but not here? Why do we have so many f*&*ing unique requirements? Why don't CASA and ASA have to justify in detail why they do NOT follow FAA requirements? Australia and CASA are just crazy!
To put it another way: the "not invented here" syndrome is alive and living in AsA and CASA! Anyone remember the Australian DME?
To put that another way. It is axiomatic in business to copy technology that works elsewhere and to only engage in bleeding edge research and development if you are already the worlds leader with, by definition, nobody else to copy.
One commandment is that if there is a system available that works well but doesn't quite suit your business processes, then you always change your business process, NEVER customise or modify the system.
Australia is hardly "leading edge" especially not in anything to do with aviation, let alone aviation regulation and air traffic control, therefore the case for ANY form of unique Australian regulation or practice (short of kangaroo protectors) is absolutely nil.