PDA

View Full Version : Wide-Area GPS Augmentation


kiwi grey
10th Oct 2008, 22:04
Flight International carried a story last week (30 September - 6 October) that said the Indian government had given the green light for launching a GPS augmentation system called Gagan. "Gagan could be interoperable with the European EGNOS system and Japan's space-based augmentation system".

This seems to imply that the Japanese system (MSAS?) and EGNOS are interoperable, and because of the close aeronautical relationship between Japan & the USA, presumably the Japanese system is interoperable with the American WAAS?

If so, why aren't we using the Japanese satellite in NZ (and Australia) to provide more reliable and more accurate navigation?
Presumably we'd need at least one uplink station, but wouln't that be relatively cheap?
What proportion of the international fleet are fitted for (or with) WAAS, so would be easily able to take advantage of the technology?

Am I 'away with the faeries' on this, or what?

K

[Mods, please move this to a more appropriate place if this doesn't go here!]

OZBUSDRIVER
10th Oct 2008, 22:50
Kiwi Grey in answer yes, all GNSS is interoperable. Yes the Japanese MTSAT provides a WAAS signal. There is a reference station in Canberra since 1992 and another in Hawaii. At this point in time no WAAS signal is provided in our region. This is due to the need of a network of surveyed receiver stations to compare the GPS signal with known position. This data is fed to an uplink to the geostationary sat as an augmentation signal. Which is then transmitted over a wide area to improve the accuracy of our GPS.

xinhua2 for your information, if this WAAS signal was available in our area. CAT I approaches would instantly become available for ANY aerodrome on the continent. YHOT YBLA YLHR and many more before it. That terrible accident down at YWBL where a very experienced RFDS pilot undershot the approach because of refraction affecting the VASIS, All these types of accidents become a thing of the past. CAT I ILS type approaches to ILS type minima, available anywhere! That is the benefit of WAAS. It represents a bigger addition to safety than any form of monitoring. It has nothing to do with ADS-B. You can definitely say it prevents CFIT, especially in the approach area.

Now that GRAS is dead, the money allocated for placement of augmentation receivers for the networks required around every capital city can now be deployed around the entire country. If there is anyone in government reading this, WAAS is a greater benefit to the entire community. Aviation benefits but so does the entire community in more ways then just one single quantifiable improvment.

The biggest reason that we do not get WAAS is because if AirServices installs the ground system they cannot recoup any fees from its operation. IT IS A FREELY AVAILABLE SYSTEM. Unlike GRAS and the pseudo-argument about soverign control and being able to charge a fee per operator.

The signal from the MTSAT is already available as a fixed satellite signal within the GNSS constellation. All it needs is for the augmentation signal to be provided and a transponder turned on.

EDIT just to add, any TSO146 GPS has the ability to provide stearing to fly a WAAS augmented ILS type approach. No points for guessing the other argument and what will be provided if everyone get their ducks in a row.

TID edit

xinhua2
10th Oct 2008, 23:13
Here we go again, soon ADSB will enter the debate, the Technology at any cost brigade are sure to come rushing in.

OZBUSDRIVER
10th Oct 2008, 23:35
Before you two, XH(gotta love that-state media service) and FB, get going, WAAS is independant of ADS-B just as TSO146 navigators are independant of ADS-B. There are a lot of people on this site alone that would gladly take WAAS availability over any other development available now.

Binghi, how about- Transport control
- Agriculture
- Prison systems
-Shipping
- Mom and Pop with their Bitchin Betty
- Delivery systems other than transport
- Equipment rental companies
- Goods monitoring systems
- State government toll companies:mad:
- Mining and exploration that only require first and second order surveying control. (Seismic comes to mind immediately)

I could go on, the list will be endless. All of these help productivity in small ways that add up to a huge national benefit. just as the freeway from ML to SY that has taken more than my lifetime to complete is helping productivity in no small amount and is provided free to everyone who wants to use it...not just the actual vehicles that actually earn the money by being able to get from point A to B in the quickest safest most efficient time available.

You know squat about DGPS, Binghi. It is not cheap and it certainly isn't wide ranging. If you must. Study about the augmentation signal that was transmitted through the JJJ network and who that service was aimed at.

EDIT- to add, just check out some of these google adds on the side of our posts to give you a better idea of what GPS is good for outside of aviation.
GOOGLE ADD (http://www.3logix.com.au/?gclid=CPfu__3pnZYCFRsRagodfBNP6A)

Jabawocky
11th Oct 2008, 00:48
Here we go again Ozbus. Dealing with the flat earthers yet again. Mind you FB is an AGW non-believer so he cant be all bad!:}

WAAS is the what Australia should be adopting for all those reasons and more.

As you point out ILS approaches with a fraction of the cost, increased safety by a significant level and reduced operating costs for Business. How many RPT/RFDS/Charter flights have had to conduct a missed approach and or divert due minima's that would otherwise have been acheivable in safety with WAAS. I would imagine the cost to industry would be massive. Has anyone ever done any figures on that alone?

Not to mention accident prevention. There is a major leap forward available in navigation safety on the market and many installed, all its waiting for is the signal.

Where is Chimbu Chuck?? ...... he has a very sensible grass roots opinion on matters like this.

I bet anyone a carton of expensive beer I know what he would say!

J:ok:

Tidbinbilla
11th Oct 2008, 01:45
WARNING: We will not tolerate any stirring and/or thread drift.

Forget the "who pays". The originator asked some simple questions. If you don't have the skills or knowledge to contribute a sensible answer - STAY OUT!:=

Cranky TID :=

james michael
11th Oct 2008, 02:28
Kiwi

CASA has comissioned - I believe BAH - to conduct a study into augmentation for Australia and the result is expected around Christmas.

I understand the GA organisation has submitted an initial paper that includes that WAAS could be available to Australia by utilising the Japanese MTSAT once sovereignty issues were resolved and subject to the ground based infrastructure provision in Australia.

The sovereign issues are one for the diplomats and probably negotiable, while the local infrastructure is the cost issue for Airservices if examined in an aviation environment alone.

It may be appropriate to go beyond the aviation compass and consult widely within government and industry users to access funding since WAAS has such wide use potential.

WAAS adds a level of safety to IFR approaches across our nation outside the GBAS/ILS umbrella. WAAS offers safety at a cost and with minimal direct return, thus the public interest (e.g. agriculture, mining) should perhaps encourage the government purse rather than Airservices having absolute financial carriage.

With the current JCP for ADS-B, the IFR TSO 146 option becomes even more attractive if WAAS was also an outcome.

Once again, the Australian problem is economy of scale. Geography versus population does not give good comparisons with other continents / countries.

OZBUSDRIVER
11th Oct 2008, 02:45
Tids, WILCO.:ok:

Kiwi Grey, to give you a good idea of the coverage of the MTSAT, just have a look at any satellite pic of our area. The same satellite carries the met package as does the WAAS transponders.

I'll see if I can find the site that shows how many ref stations and uplinks required for the US.

Bob Murphie
11th Oct 2008, 03:00
The BAH to study the benefits of WAAS for Australia and including, but not limited to aviation, was commissioned about 12 months ago by DOTARS, not CASA, and in its completon did not support WAAS.

james michael
11th Oct 2008, 03:44
Tid

On reflection, for clarification not to be cantankerous :) - the matter of who pays is actually fundamental to the original question that started the thread.

If the "Gummint" pays, aviation can piggyback. If ASA has to front the $ I'd hate to try and do the CBA.

Bob

You may care to view Approach vertical guidance study (http://www.casa.gov.au/newrules/airspace/apv.htm) and be enlightened.

The Aviation Policy Group (APG) has requested CASA to undertake on its behalf such a study and CASA is pleased to announce that Booz Allen Hamilton has been selected to complete the study.I believe it commenced in early 2008 and is not yet completed.

When it is complete and reports, it may answer the initial poster's question ;)