Brainstorming HEMS
Joined: Oct 2003
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From: Over here
Are those part of the European GPS system? In the US, almost every modern GPS uses WAAS (Wide Area Augmentation System) which is a combination of ground and satellite based augmentation. I haven't heard of GBAS or SBAS before.
Joined: May 2003
Posts: 921
Likes: 30
From: Europe
They are the accepted generic terms for satellite based and ground based systems.
WAAS is the US implementation of SBAS as is EGNOS in Europe (others are: WAGE - for the DoD; MSAS and QZSS - for Japan; StarFire and Starfix - commercial; and GAGAN - for India).
Whilst SBAS is the generic term referring to any such satellite-based augmentation system, under ICAO Standards, SBAS must transmit a specific message format and frequency which matches the design of WAAS.
Generally, GBAS networks are local (within 20km) using VHF and UHF radio bands.
The reason aumentation systems were suggested was because, not only do they add accuracy and integrity to a GPS system, they are also enabling technologies for more accurate Point in Space (PinS) procedures (which of course can also use the raw GPS signal). If as suggested in an earlier post, there is a proposal to narrow the navigation lanes and hence take advantage of less restrictive obstacle clearance, such accuracy and integrity will be essential.
Whilst formal routing and procedures could benefit from any advance in these systems (and may permit a lower helicopter IFR routing overlay - or is it underlay?), it is not clear how this will have a great impact on the HEMS safety record.
If we go back to the list and rank the elements for potential improvements in safety - this, for me, would be near the bottom.
Jim
WAAS is the US implementation of SBAS as is EGNOS in Europe (others are: WAGE - for the DoD; MSAS and QZSS - for Japan; StarFire and Starfix - commercial; and GAGAN - for India).
Whilst SBAS is the generic term referring to any such satellite-based augmentation system, under ICAO Standards, SBAS must transmit a specific message format and frequency which matches the design of WAAS.
Generally, GBAS networks are local (within 20km) using VHF and UHF radio bands.
The reason aumentation systems were suggested was because, not only do they add accuracy and integrity to a GPS system, they are also enabling technologies for more accurate Point in Space (PinS) procedures (which of course can also use the raw GPS signal). If as suggested in an earlier post, there is a proposal to narrow the navigation lanes and hence take advantage of less restrictive obstacle clearance, such accuracy and integrity will be essential.
Whilst formal routing and procedures could benefit from any advance in these systems (and may permit a lower helicopter IFR routing overlay - or is it underlay?), it is not clear how this will have a great impact on the HEMS safety record.
If we go back to the list and rank the elements for potential improvements in safety - this, for me, would be near the bottom.
Jim
Joined: Dec 2001
Posts: 1,835
Likes: 3
From: Philadelphia PA
JimL:
Thanks for the definitions. New to me!
The improvement in safety would be difficult to trace to only using Augmented GPS and much narrower routings. It would be part of a larger package that promoted using IFR techniques, such as pre-planned routes to common points from which to proceed to a scene, etc.
A change in overall mentality is what's needed - anything that can be done to improve our methods would be most useful.
Thanks for the definitions. New to me!
The improvement in safety would be difficult to trace to only using Augmented GPS and much narrower routings. It would be part of a larger package that promoted using IFR techniques, such as pre-planned routes to common points from which to proceed to a scene, etc.
A change in overall mentality is what's needed - anything that can be done to improve our methods would be most useful.
Joined: Mar 2006
Posts: 358
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From: On the move...
The longest journey starts with one step.
If there are fatals that can be attributed to the trip back with patient, then fixing that part of the journey is still needed. (One of the last fatals - doing a missed approach to an airfield 'cause they couldn't get into the hospital)
Remember if you can create precision (GPS) approaches to a hospital, isn't that the most common destination and therefore needs to be dealt with?
I like the idea of having pre detemined routes, but again it comes back to your Area of Ops.
Good luck gents.
If there are fatals that can be attributed to the trip back with patient, then fixing that part of the journey is still needed. (One of the last fatals - doing a missed approach to an airfield 'cause they couldn't get into the hospital)
Remember if you can create precision (GPS) approaches to a hospital, isn't that the most common destination and therefore needs to be dealt with?
I like the idea of having pre detemined routes, but again it comes back to your Area of Ops.
Good luck gents.
Joined: Oct 2003
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From: Over here
WAAS was created solely to increase vertical accuracy. For routes in the horizontal plane, it only increases accuracy by a few (less than 10) meters, and does not allow any increase in routing precision. Even without WAAS, GPS is more accurate than ILS in the horizontal dimension. Use of WAAS does permit the GPS to warn of obstacles or not, based on altitude. It was created to allow precision GPS approaches, which are not possible without it, but does little for horizontal accuracy. If the routes are TERPed beforehand, WAAS isn't necessary, but if the routes are going to be flown without being previously checked, then it can help avoid obstacles, as long as the database is completely correct, and nobody has erected anything since it was installed in the GPS. I don't trust obstacle databases completely, at least not enough to bet my life on their accuracy.
Joined: Sep 2007
Posts: 186
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From: US
JimL
From your post of 22 November:
" What might be required is to break out the various elements of the existing IFR system into its constituent parts to see what might be usefully employed. "
Excellent.
WIII
From your post of 22 November:
" What might be required is to break out the various elements of the existing IFR system into its constituent parts to see what might be usefully employed. "
Excellent.
WIII
Joined: May 2002
Aviation Qualifications: ATP+Mil
Posts: 18,633
Likes: 1,072
From: Downeast
Might be interesting to look back over five years and see what has happened since all this Brain Storming has taken place. What ideas have been adopted, which ones should have been but were not.....and then analyze the reasons why not.
Has EMS gotten any safer over the five year period?
Has EMS gotten any safer over the five year period?
