WAAS for Australia – you heard it here first!
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alphaC,
Yes, you have certainly nailed it. In designing RNP, to justify the cost, the major selling point was idle descent and saving fuel.
As you noted, idle descent does not work in the ATC environment.
We worked this out with MVD RNP procedures for CASA/ASA. With the coded procedure, a set of strategically placed speed restrictions would make the RNP and non-RNP ac play in the same sandbox for ATC.
I struggled with this for some time, trying to make the RNP AR turns, acceptable for A380 and 737-8, etc...you cant have several sets of waypoints that work for the ac, and expect ATC to manage them...
toss in wake sep when you now have everyone on a coded procedure, ie same H/V flightpath, it all gets real interesting, real fast...
EDIT: As AC noted, AUS will not be seeing WAAS anytime soon, if ever. It is old tech, so why bring it up, just to have it outdated..
Yes, you have certainly nailed it. In designing RNP, to justify the cost, the major selling point was idle descent and saving fuel.
As you noted, idle descent does not work in the ATC environment.
We worked this out with MVD RNP procedures for CASA/ASA. With the coded procedure, a set of strategically placed speed restrictions would make the RNP and non-RNP ac play in the same sandbox for ATC.
I struggled with this for some time, trying to make the RNP AR turns, acceptable for A380 and 737-8, etc...you cant have several sets of waypoints that work for the ac, and expect ATC to manage them...
toss in wake sep when you now have everyone on a coded procedure, ie same H/V flightpath, it all gets real interesting, real fast...
EDIT: As AC noted, AUS will not be seeing WAAS anytime soon, if ever. It is old tech, so why bring it up, just to have it outdated..
Under fire....I call BS on your statements re-the number of WAAS for LPV and LV. Methinks you better learn how to use google before making comments like that. All that is required for LPV is A WAAS signal WAAS level 3 equipment fitted and an authorized approach. LV is LPV localized guidance with BARO. Got nothing to do with how many WAAS birds it sees.
I am always welcome of any link that supplies information to back up any claim
Always ready to admit fault and demure 
I am always welcome of any link that supplies information to back up any claim
Always ready to admit fault and demure
EDIT: As AC noted, AUS will not be seeing WAAS anytime soon, if ever. It is old tech, so why bring it up, just to have it outdated..
Also I have heard the Airbus 350 will have SBAS capability fitted as standard.
By the way ILS's are old tech too but they're still widely used and still being installed
OZBUSDDRIVER
It is my understanding as well that only one SBAS satellite signal is required for LPV etc.
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WAAS is outdated, and is only being implemented at airports instead of an ILS. It is just anoth augmentation scheme of GPS, but, unfortunately, did require a different receiver, which the airline neglected to purchase, given the cert for RNAV/RNP.
WAAS is really being advertised for GA and smaller aircraft.
OZbusdriver. Perhaps you should learn to Google. WAAS needs two ground stations and 2 sats to provide LP and 3 sats to provide LPV. As staed, WAAS is only a correction factor to tune up GPS, so like GPS, did you really think you would get vertical with 2 sats?
"The GPS information collected by the WRS sites is forwarded to the WAAS Master Station (WMS) via a terrestrial communications network. At the WMS, the WAAS augmentation messages are generated. These messages contain information that allows GPS receivers to remove errors in the GPS"
So you need many ground stations that coordinate with the 2 master stations for rebroadcast of the corection factor.
As far as the numbers, it was directly from the FAA website, which perhaps even you can determine how to search for and read...
Navigation Programs - Satellite Navigation
WAAS is really being advertised for GA and smaller aircraft.
OZbusdriver. Perhaps you should learn to Google. WAAS needs two ground stations and 2 sats to provide LP and 3 sats to provide LPV. As staed, WAAS is only a correction factor to tune up GPS, so like GPS, did you really think you would get vertical with 2 sats?
"The GPS information collected by the WRS sites is forwarded to the WAAS Master Station (WMS) via a terrestrial communications network. At the WMS, the WAAS augmentation messages are generated. These messages contain information that allows GPS receivers to remove errors in the GPS"
So you need many ground stations that coordinate with the 2 master stations for rebroadcast of the corection factor.
As far as the numbers, it was directly from the FAA website, which perhaps even you can determine how to search for and read...
Navigation Programs - Satellite Navigation
http://www.gps.gov/technical/ps/2008...e-standard.pdf
Sorry, cannot do links with my phone......a little light reading and get back to me
well buggame....it does do links.....enjoy
Sorry, cannot do links with my phone......a little light reading and get back to me
well buggame....it does do links.....enjoy
To explain again what Australia has and needs to do to enable WAAS.
We already have a master station in Canberra that talks to the MTSAT as a reference station only. We already have a ground constellation of 28 ADS-B receiver sites...already accurately surveyed...talking to a central facility...that can be used as the monitoring sites. Do need a few along the eastern seaboard to complete the network. Another uplink somewhere west of Alice Springs and then get a transponder on the next two NBN birds....(I do note, the FAA have a goal to have redundancy with their GEO birds. Although, only one WAAS signal is required....conceding that I have never realised this until challenged...learn something every day)
We already have a master station in Canberra that talks to the MTSAT as a reference station only. We already have a ground constellation of 28 ADS-B receiver sites...already accurately surveyed...talking to a central facility...that can be used as the monitoring sites. Do need a few along the eastern seaboard to complete the network. Another uplink somewhere west of Alice Springs and then get a transponder on the next two NBN birds....(I do note, the FAA have a goal to have redundancy with their GEO birds. Although, only one WAAS signal is required....conceding that I have never realised this until challenged...learn something every day)
Underfire
Your statement here indicates to me you don't really know how SBAS works.
The vertical and lateral calculations are made by using the GPS constellation. The SBAS satellite is only used to broadcast a correction signal based on the info provided by the ground stations. This correction signal is used by the GPS receiver to refine is calculated location.
There is no 3D signal requirement for the correction signal. Remember it is a wide area augmentation which works on a similar principle to local area augmentation where a signal is broadcast to the local area from a single ground station.
You haven't explained why you say SBAS is outdated. You just keep saying it's outdated when there is evidence to show otherwise.
2 sats to provide LP and 3 sats to provide LPV. As staed, WAAS is only a correction factor to tune up GPS, so like GPS, did you really think you would get vertical with 2 sats?
The vertical and lateral calculations are made by using the GPS constellation. The SBAS satellite is only used to broadcast a correction signal based on the info provided by the ground stations. This correction signal is used by the GPS receiver to refine is calculated location.
There is no 3D signal requirement for the correction signal. Remember it is a wide area augmentation which works on a similar principle to local area augmentation where a signal is broadcast to the local area from a single ground station.
You haven't explained why you say SBAS is outdated. You just keep saying it's outdated when there is evidence to show otherwise.
There are some misconceptions here. The availability or not of SBAS in Australia has nothing to do with CASA. There is no government interest in funding the facility. Providing infrastructure is NOT part of CASA responsibilities under the Civil Aviation Act. CASA staff in the relevant areas are supportive. BARO-VNav is the only viable vertically guide procedure that can be developed with minimal infrastructure - broadcast QNH.
Australia, as a signatory to the Chicago Convention, has an obligation to support ICAO including the policy of moving all navigation to space based technology. SBAS is not an ICAO mandate.
Australia, as a signatory to the Chicago Convention, has an obligation to support ICAO including the policy of moving all navigation to space based technology. SBAS is not an ICAO mandate.
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There is no government interest in funding the facility
For what appears to be minimal cost, we could utilise the Japanese system, so the cost benefit calculation is shifted to be more favourable to this being implemented, given the wide ranging usefulness to many groups in the nation, not just aviation, not to mention the safety benefit.
The availability or not of SBAS in Australia has nothing to do with CASA.
Providing infrastructure is NOT part of CASA responsibilities under the Civil Aviation Act.
CASA staff in the relevant areas are supportive.
BARO-VNav is the only viable vertically guide procedure that can be developed with minimal infrastructure - broadcast QNH.
Australia, as a signatory to the Chicago Convention, has an obligation to support ICAO including the policy of moving all navigation to space based technology. SBAS is not an ICAO mandate.
This conversation is about Australia supporting the ICAO mandate to provide approaches with vertical guidance. The PBN mandate it different. You are correct, SBAS is not an ICAO mandate. But APV is an ICAO mandate and SBAS will allow Australia to meets its obligations.
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27/09
The SBAS signal requires the 3 sats to provide the vertical correction factor.
If you only have 2 available, the correction factor does not include vertical, so you only have LP.
As Ozbusdriver stated, there were 4 sats, and one went down, so they moved the one that was over the Central Pacific so that Alaska would be covered with 3 for LPV.
It is outdated, simply because the commercial airlines have little interest in retrofitting a fleet for WAAS. It is useful for GA and remote airfields, and that is its market.
Commercial fleets simply moved past the technology, going with RNAV (GPS) then RNAV (RNP)/APCH,AR then to GBAS/GLS...
EDIT: BTW, why are they going with 27/09 R and L, when it will just put it all in crosswind conditions? What's up with 16/34 R & L??
Your statement here indicates to me you don't really know how SBAS works.
If you only have 2 available, the correction factor does not include vertical, so you only have LP.
As Ozbusdriver stated, there were 4 sats, and one went down, so they moved the one that was over the Central Pacific so that Alaska would be covered with 3 for LPV.
It is outdated, simply because the commercial airlines have little interest in retrofitting a fleet for WAAS. It is useful for GA and remote airfields, and that is its market.
Commercial fleets simply moved past the technology, going with RNAV (GPS) then RNAV (RNP)/APCH,AR then to GBAS/GLS...
EDIT: BTW, why are they going with 27/09 R and L, when it will just put it all in crosswind conditions? What's up with 16/34 R & L??
Underfire
I cannot find any info to support this statement, in fact the only reference is to the correction signal from THE satellite (singular). There have been many periods when there has only been two WAAS satellites so I still say you're mistaken re the need for three WAAS satellites for vertical guidance on an approach.
Riddle me this then, why are Airbus putting SBAS receivers into the A350?
The SBAS signal requires the 3 sats to provide the vertical correction factor.
It is outdated, simply because the commercial airlines have little interest in retrofitting a fleet for WAAS. It is useful for GA and remote airfields, and that is its market.
Commercial fleets simply moved past the technology, going with RNAV (GPS) then RNAV (RNP)/APCH,AR then to GBAS/GLS...
Commercial fleets simply moved past the technology, going with RNAV (GPS) then RNAV (RNP)/APCH,AR then to GBAS/GLS...
It appears that anti CASA sentiment colours judgement or knowledge. APV is a generic description of a range of approaches with vertical guidance. They include Baro-VNav and LPV where vertical guidance is provided through the use of SBAS.
Australia is only one of many countries that do not have access to SBAS. Performance Based Navigation is a concept that includes enroute navigation, departure and approach procedures classified according to the accuracy of navigation performance of the aircraft nav systems. There is no ICAO LPV mandate. There is an encouragement to implement vertically guided approaches where feasible. That is why the ICAO PBN Manual includes a range of specifications for such approaches.
Who is the CASA person who does not support SBAS?
Where in the Civil Aviation Act is CASA given the infrastructure responsibilities ascribed by alpha centauri?
If the GA community is willing to pay tens of millions of dollars any thing is possible. The other possible users aren't pushing for this.
Australia is only one of many countries that do not have access to SBAS. Performance Based Navigation is a concept that includes enroute navigation, departure and approach procedures classified according to the accuracy of navigation performance of the aircraft nav systems. There is no ICAO LPV mandate. There is an encouragement to implement vertically guided approaches where feasible. That is why the ICAO PBN Manual includes a range of specifications for such approaches.
Who is the CASA person who does not support SBAS?
Where in the Civil Aviation Act is CASA given the infrastructure responsibilities ascribed by alpha centauri?
If the GA community is willing to pay tens of millions of dollars any thing is possible. The other possible users aren't pushing for this.
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Alpha,
Back to post #102. Yes you illustrate why WAAS will likely never make it to AUS.
The ICAO mandate allows quite a bit of leaway for vertical guidance: The 'V' being supplied by Baro, and of course, GBAS (of which ASA is 50% owners of HW SmartPath)
Resolves that:
States and planning and implementation regional groups (PIRGs) complete a PBN implementation plan by 2009 as a matter of urgency to achieve:
1) implementation of RNAV and RNP operations (where required) for enroute and terminal areas according to established timelines and intermediate milestones; and
2) implementation of approach procedures with vertical guidance (APV) (Baro-VNAV and/or augmented GNSS) for all instrument runway ends, either as the primary approach or as a back-up for precision approaches by 2016.
That is not correct. ICAO and FAA P77 obstacle surfaces only go straight out to 50,000 feet to 1200' AT, tapering to the runway width.
RNP obstacle assessment does not taper, but follows containment width +ANP growth (ICAO surface is abit different) and is along the entire coded part of the flightpath, with AR turns, it is far outside the areas maintained by the government database. The missed approach OC surface for RNP is much different, and of course, EO missed is a custom not contained in the criteria.
While the govt maintains the obstacle and NOTAM services for public procedures, they do not have anything to do with the tailored/custom procedures that QANTAS and others fly. NOTAM assessment and obstacle assessment are done 24/7/365 by GE on these procedures.
EDIT: Most of the baro procedures sitting there, are sitting there because of enviro... there are many approved, but are perm NOTAM's out...
While Airbus is supporting SBAS for access to other markets, it is important to understand that Boeing does not support SBAS. (the European system has a long way to go before they see any sorts of accuracy that has been alluded to. ICAO regs currently limit SBAS to 250 HAT anyways...)
NATS SBAS
Airbus APV (good explaination of Airbus system thoughts)
Back to post #102. Yes you illustrate why WAAS will likely never make it to AUS.
The ICAO mandate allows quite a bit of leaway for vertical guidance: The 'V' being supplied by Baro, and of course, GBAS (of which ASA is 50% owners of HW SmartPath)
Resolves that:
States and planning and implementation regional groups (PIRGs) complete a PBN implementation plan by 2009 as a matter of urgency to achieve:
1) implementation of RNAV and RNP operations (where required) for enroute and terminal areas according to established timelines and intermediate milestones; and
2) implementation of approach procedures with vertical guidance (APV) (Baro-VNAV and/or augmented GNSS) for all instrument runway ends, either as the primary approach or as a back-up for precision approaches by 2016.
This statement is full inaccuracies....there is no extra obstacle oversight requirement for an RNP-AR beyond that which exists for any other approach.
RNP obstacle assessment does not taper, but follows containment width +ANP growth (ICAO surface is abit different) and is along the entire coded part of the flightpath, with AR turns, it is far outside the areas maintained by the government database. The missed approach OC surface for RNP is much different, and of course, EO missed is a custom not contained in the criteria.
While the govt maintains the obstacle and NOTAM services for public procedures, they do not have anything to do with the tailored/custom procedures that QANTAS and others fly. NOTAM assessment and obstacle assessment are done 24/7/365 by GE on these procedures.
EDIT: Most of the baro procedures sitting there, are sitting there because of enviro... there are many approved, but are perm NOTAM's out...
While Airbus is supporting SBAS for access to other markets, it is important to understand that Boeing does not support SBAS. (the European system has a long way to go before they see any sorts of accuracy that has been alluded to. ICAO regs currently limit SBAS to 250 HAT anyways...)
NATS SBAS
Airbus APV (good explaination of Airbus system thoughts)
Last edited by underfire; 21st Dec 2013 at 20:44.
Underfire, Airservices is also now the publisher of RNP-AR approaches and I can assure you they were designed under existing obstacle protection framework. There are no differences, from other types of approaches.
As for Baro, enviro assessments are not required as there is no track or height change. The box waiting to be ticked is an authorisation to publish from CASA .....they won't do this until they figure out how to validate them.
As for Baro, enviro assessments are not required as there is no track or height change. The box waiting to be ticked is an authorisation to publish from CASA .....they won't do this until they figure out how to validate them.
Last edited by alphacentauri; 21st Dec 2013 at 22:07.
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The other possible users aren't pushing for this.
Just because other potential users aren't yet actively lobbying does not mean they are disinterested in it coming to fruition.
Again we should lobby government if we believe this is both worthwhile and there is a technical opportunity with the Japanese and/or piggyback on soon to be launched NBN satellites.
Vag277,
I didn't say CASA had infrastructure responsibilities. What I said is that CASA advises the Government on national infrastructure. The CASA board is appointed by the Minister (for whatever it is called these days). If the department ever have a question, who do you think they go to for advice?. Airservices board is appointed and reports in exactly the same way.
Do you really think I am going to name CASA people on here?
Mate, you may well be correct and I am more than happy to say I was wrong. But from where I have to work and the people I deal with everyday, this is what we are being told and how it looks from my end.
I didn't say CASA had infrastructure responsibilities. What I said is that CASA advises the Government on national infrastructure. The CASA board is appointed by the Minister (for whatever it is called these days). If the department ever have a question, who do you think they go to for advice?. Airservices board is appointed and reports in exactly the same way.
Do you really think I am going to name CASA people on here?
Mate, you may well be correct and I am more than happy to say I was wrong. But from where I have to work and the people I deal with everyday, this is what we are being told and how it looks from my end.