Nav aids in Aus to be shut down?

[FlightPathOBN]

OZ,

The GBAS signal is proprietary? That is not correct, both GBAS, WAAS and other systems are based on the standard ARINC 424.

WAAS will still have the same limitations as GPS or GBAS because it is still based from a sat. Its just a correction factor of the GPS sat signals, its just, sat based, where GBAS is ground based.

WAAS certified aircraft system is completely different than the GPS system.
It is different receivers, different antennae, and, same as GPS, must have at least 2 systems for certification.

WAAS needs quite the infrastructure to operate. Currently in the US, there are about 25 ground reference stations positioned across the United States that monitor GPS satellite data. Two master stations, located on either coast, collect data from the reference stations and create a GPS correction message. This correction accounts for GPS satellite orbit and clock drift plus signal delays caused by the atmosphere and ionosphere. The corrected differential message is then broadcast through one of two geostationary satellites, or satellites with a fixed position over the equator. So its not free by any means. AUS would have to set up similar system around the Country if they wanted the same accuracy results.

Virtually no commercial aircraft have been WAAS certified. While there are WAAS certified stand alone units, a WAAS coupled unit requires the certification of the aircraft, including flight test. Manufacturers or the airlines, do not want to switch to the system.
Currently, there are 2 WAAS sats for the US, so even one partially degraded, puts the whole system down. Like GBAS, the WAAS aircraft must have the WAAS artificial horizon for guidance.
You must still check RAIM, and monitor RAIM inflight.

So all that, and there are how many procedures available to use?

The GBAS signal broadcasts the approach procedure, That is why it is far better, as WAAS just giving a corrected GPS algorithm. The GBAS is broadcasting the same correction factor, its just ground based, AT the airport you are going to.
Here is an example of the GBAS signal, which the aircraft will use, just like the ILS beam, for approach. But, unlike the ILS beam, the GBAS is a signal which isnt interrupted by infrastructure or other aircraft.
As you can see, there is some great features, such as broadcast of multiple GPA, from which the pilot can select, and currently curved approach procedures are being tested:

"RX_WEEK";"RX_TOM";"GBAS_ID";"FAS_VAL";"FAS_LAL";"OPTYP";"SB AS_ID";"AIRPORT_ID";"RW_NO";"RW
_LTR";"APP_DESIG";"ROUTE_IND";"RPDS";"RPID";"LTP_LAT";"LTP_L ON";"LTP_H";"DFPAP_LAT";"DFPAP
_LON";"TCH";"GPA";"C_WIDTH";"RW_LEN_OFFSET";"CRC_OK"
1634;303799.437500;"TATM";10.000000;40.000000;0;0;"EDVE";26; 0;1;"Z";21;"G26A";52.31964167;
10.56400556;131.300000;-0.00098056;-0.01751667;15.240000;3.000000;80.000000;0;1

1634;303800.437500;"TATM";10.000000;40.000000;0;0;"EDVE";26; 0;1;"Y";22;"G26B";52.31964167;
10.56400556;131.300000;-0.00098056;-0.01751667;15.240000;3.200000;80.000000;0;1

As far as AUS buying in, ASA is a 50% business owner of SmartPath. SmartPath is already CAT I certified, and CAT III autoland is being certified, but already in use in some countries by their military aircraft.