Howabout
WAAS is not required for ADS-B accuracy.
ADS-B is in use across Australia today by airlines - we don't have WAAS.
If you need references, ask.
This may help:
1.8 Australia has analysed 3 months’ of ADS-B data from aircraft which are known to have acceptable ADS-B avionics – i.e. aircraft which have been authorised to receive ADS-B services in Australia. We have examined about 160 million ADS-B reports and correlated these with the GPS
receiver onboard the aircraft. Details of the analysis method are discussed in Appendix A.
1.9 None of the authorised aircraft have TSOC145a/C146a avionics and none of the avionics are SBAS/ WAAS certified. However some aircraft are fitted with GPS receivers that are “SA Aware.”
JM