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Elevated airports?

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Hope someone can help:Recently I bought Raimundo Taburet's Mesh files for Central and West Europe and installed them.Looks good, however...have a look at the picture.It's Arnsberg Apt. which now shows extremely elevated.I've seen this with dozens of other (mainly smaller) airports.The all seem to be situated on a kind of 'mesa' ;)Anything I did wrong?- Gideon (EHAM)

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Hi Richter36.You didn't do anything wrong. Taburet's mesh simply wasn't corrected for the FS2002 airfields.All airfields for FS2002 have flatten coding as part of the airfield. This coding is 'tuned' to the default FS2002 mesh elevations. If the new mesh is not at the same elevation under the airfield, you'll get a mesa or a pit. Payware or freeware mesh will do this. If the mesh is not 'corrected' to the default airfield elevation, then the fix is to write a new flatten command to lower ( or raise ) the airfields. Some mesh authors include a set of airfield correction bgls with their mesh. Perhaps, Taburet did not.If so, your money wasn't enough to pay for the extra work of the necessary flattens. In that case, you could try ask for a refund. Or you could learn SCASM code ( or the new TMF flatten code ), and write your own. Sorry.

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Hi Richter36.I didn't mean to imply the mesh is 'wrong' or does not look good. This airfield altitude problem does affect all 3rd party mesh, freeware or payware. Microsoft must have spent many hours setting the altitudes for the default airfields... and did a decent job, overall. If Ray were to include all airfield altitude corrections for this mesh, it could mean thousands of corrections, and would cost him dozens, or hundreds, of man-hours to accomplish. He probably would not even sell his mesh, as the price would get too high to cover his labor costs. Oddly, the more detailed the mesh, the worse the problem may get! And Ray is right, in that the 'correction' may leave the appearance of the airfield looking strange, as one end may lie in a pit, while the other sits on a plateau. Again, M$ seems to have done a decent job, here, considering the airfields must lie flat.Don't expect freeware mesh to be any better in this regard. Some authors will include altitude corrections; most don't. The only advantage for freeware, is that because it is free, you don't lose anything for your disappointment, except download and installation time.

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Dear Rambaflappy, You are very much right on your last post - regarding the hours of work which will go into that kind of job. Furthermore we must consider - the extension which the mesh scenery covers - the bigger - the more work. For instance - in that kind of mesh of Eastern Europe - which covers Such a vast area - therefore there are quite lots of airports in that area. It will be feasable - to improve - that kind of problem in mesh which covers only - strecthes of terrain - or country partial coverage - where you have to deal with just few airporsts - But of course - somentimes - simmers do email me and let me know that some airport can be badly affected - if it is too much then can find the remedy - of course if possible. We see what happen with fs2004 - I heard that can be the sim which will provide solution to these problems - but right now is just words I heard - I rather see it with my eyes to believe. By the way - have fun Ray (Ps. What does it mean Rhumbaflappy??)

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Ok, so what you guys are saying is that there's no mesh available (commercial or freeware) that does not have this problem?Main cause: the huge amount of work to correct every flatten for each airport? Is that correct? Thanks for your extensive explaination on this issue so far!- Gideon (EHAM)

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Yes. Thousands of airfields for Europe alone. Each requiring a flatten code to make the field lie flat to the ground. The work would probably be too extensive for a commercial vendor... after all, he's trying to make a living wage from his work. You have to watch the man-hours invested. Ray has produced some great-looking mesh for our sim. He probably would not continue, if he couldn't make a profit from it. I understand his situation, and I don't find fault in it. Perhaps he could give buyers a warning about airfield altitudes, but no one else does this... and such a warning might leave the impression that his mesh is somehow inferior, when it is certainly no worse than any other mesh in this regard. If someone, payware or freeware, is willing to adjust all the airfields along with his mesh, then he should certainly advertise that! But, as Ray pointed out, altitude is only part of the problem. We also need to regard the slope of the airfield. Also, changing the altitude of the field itself may affect other aspects of the sim... leading to problems with navigation, landings, saved flights and lessons. In truth, the mesh would have to be adjusted... not the airfield, whether or not the airfield is correct.I give Microsoft a lot of credit for the look of the default... they matched the altitudes of mesh and airfields pretty good. But we're all stuck with the thousands of airfield elevations they left us.Hopefully, as Ray points out, FS2004 code will place airfields at mesh-relative ground level, and allow for the sloping of the field, itself. Or perhaps, better elevation data will become economically feasible worldwide. Designers for US mesh have an advantage here, as such data is already available. Accurate European data is horribly expensive, and sometimes not available. This means Ray, and other designers, must use exotic methods to produce a realistic-looking mesh. Some use oversampling. Some use altering of the input DEM data. The better the data, the better the resulting mesh, and the better the fit of the airfields, ( and the less need to alter the data or oversample the mesh ).

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HI Richard,Just to add a bit to your correct answer, probably 98% of the problem lies in FS200x's flat-runway limitation. The other 2% is most likely errata in Jeppesen's airport elevation/location database.I highly doubt that MS hand-coded many, if any, of these airport elevations. They probably just imported the airport elevations from the Jeppesen database.The problem lies in the difference between airport elevation and the threshold elevations of the airport's runways. I would dare to say that NO runway in the real world is perfectly flat, yet FS200x cannot depict anything BUT a flat runway. If you study the runway threshold elevations at Airnav.com, you will almost never find the same elevation at both ends of a runway. Meanwhile, the listed airport elevation is usually the highest ground elevation on the airport grounds, which in most cases something entirely different than any runway threshold elevation on the airport.The problem will not be too glaring in those places where the ground elevation doesn't vary by more than 15-20 feet. But in those areas where the ground elevation varies by a significant amount (two places come to mind immediately--Davis-Monthan AFB in Tucson and Tucson International), there is simply no getting around the problem. You can lower the airport to get rid of the mesa, but then you end up with a ditch at the other end. Danged if you do, danged if you don't.While a small percentage of these problems can be fixed by correcting the airport's elevation or location, most of them we just have to live with until MS creates the code to depict runways as they really are instead of perfectly flat.Justinhttp://www.fsgenesis.com

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Gideon>Ok, so what you guys are saying is that there's no mesh >available (commercial or freeware) that does not have this >problem? The Visual Flight UK & Ireland mesh doesn't have this problem. We've taken the view that as the airport elevations and locations in FS2002 are correct (this is certainly true for the UK & Ireland), they form a useful additional input into the mesh creation process.John FarrieVisual Flighthttp://www.visualflight.co.uk/

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John always ready to take opportunity to advertise his products! ehehe that is understandable.That is why - in Fs2002 airports altitudes and positions - are very often wrong! so if John Uk mesh display flat terrain around airports - that mean that the mesh is also wrong! Ray

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>John always ready to take opportunity to advertise his >products! ehehe that is understandable. Sorry, I thought it would be OK to provide a very short and factual response to Gideon's question. >That is why - in Fs2002 airports altitudes and positions - >are very often wrong! so if John Uk mesh display flat >terrain around airports - that mean that the mesh is also >wrong! FS2002's airport elevations in the UK & Ireland all tie in accurately with the official UK AIP information. As for position, some of the individual runways may be very slightly out of position or misaligned, but not so much as to affect the accuracy with regard to the mesh - the airports are in the correct location. I very much suspect this is the same in most of Europe, but I'd be interested if anyone has any examples where it's not the case.By the way, the Visual Flight mesh isn't flat around an airport if the actual terrain around the airport isn't flat in real life.John

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Well, I noticed it's a quite a 'political' subject :)The bitter pill still is:You buy a mesh because you (want to) fly VFR.VFR brings you mostly to the smaller, outback airports.Exacly those that didn't got the attention from MS. Not to blame them, but it is the case.Hence..mesh is nice, but don't go flying anywhere or you end up with quite some challenging 'Funchal' approaches.. ;)I will check out your mesh John. Don't have anything for the UK yet.cheers!- Gideon (EHAM)

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Well we can say - Uk has basically a mostly low elevation terrain - therefore those problem are more easy to fix - and also with some luck avoidable.But I do lots of 10 m mesh - experiment - and even 10 m dem - which are in absolute the best available - no matter what - 10 m dem is the most precise and accurate elevation data - available still get those problem in places - That is why - my opinion airport in fs2002 are not extremely well placed - and I've reports from pilots - where airports are often 500 m on the left or on the right - - How can you claim that mesh no matter who desing it - with what dem - can be accurate and fitting nicely into airports?? - If you editing the area - then the surronding mesh is not what it should be - cause you have change it to fit the airport nicely.Ray

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After looking at Visual Flight Scenery I considered that my local area was far better in Visual Flight than I could produce.This is the Vale of Evesham, UK.I was able to adjust my three airfields, that are not included in FS2002, to make the elevations fit into Vistual Flight scenery.I am now waiting for the proposed UK aerial collection so that I can add actual scenery to Visual Flight mesh and place my buildings, etc in the correct places.Versions of my local area for FS98, FS2000 and Fs2002 are at my website www.users.globalnet.co.uk/~ngo plus a special version for FS2002 for those with Visual Flight Scenery.

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Dear Ngo;Where is the Mesh on that pictures? Looks like the Padana Valley in North Italy!Try to do the same with 10 m usgs mesh - if you can -! the Real Mesh! Ray

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We're not discussing the US, where good accurate data is available.The original post was discussing Europe.Where is your 10m DEM of Europe?Other than UK and Ireland and Parts of Portugal There's very little mesh that exists that's based on data readily available on the web.Outside of Norfolk (UK) I wouldn't say England is Flat. It has gently rolling pastures which are best depicted using the Mesh from Visual Flight. Anything else is based on 1 Km point data readily found on the web.We all welcome everyone's contribution to this hobby.Again I must say that different map projections yield different results. There's no right or wrong to it. Suffice it to say the earth isn't flat and it isn't a sphere either! Since it spins, the top & bottom are somewhat flattened making reference points difficult to define.So we are left with 'How does it look?'To make a more detailed mesh requires data from sources other than the web. You might think that buying maps and reading the contours and gleaning information from them would be a solution. Well, no! Map publishers jealously guard their copyrighted maps and will go after anyone who tries to use their products to produce accurate DEM's, Including meshes for FS.I think a lot of work has gone into the UK Mesh from Visual Flight.The developers live in the country whose mesh they produce.My recent trip to the UK verified the high level of accuracy this mesh contains. Using airport elevations as extra data points makes sense and improves the mesh. Sure, I would love a 10m mesh but the best we can hope for is 30m in the not too distant future. I should look up my friends at JPL and ask for a copy today.

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Exactly Ihor;Sorry - we do not have 10 m dem for Europe just yet! Maybe in the year 2100 can be available! I refer to the picture above - where I can not see any elevations but just few cows standing up - and therefore editing can be a much more simple task - rather than areas where elevation are far higher - - My motto is - IF A COW CAN STAND UP - AN AIRPORT WILL FIT WELL!! Howewer the best you can hope for Europe is 90 m - and is not in the near future.Ray

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Unfortunately, that timeline was published before 9/11.Since then, there are now numerous hoops to jump through before the data can be obtained. NIMA, the US Military Mapping Agency, now controls (tightly) the access to the data.JustinFSGhttp://www.fsgenesis.com

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Sorry Ray, you really ought to get your facts straight before implying any criticism of the excellent work by John. The UK is by no means flat! I tried your mesh but found so many errors (not your fault, I know, you can only work with the data available) that I had to give up on it. The MS default was actually better in some places. You did manage to make Scotland and Wales a bit more rugged, but by no means craggy enough for us locals. Then Visual Flight came along and I didn't mind paying the price for something so excellent. John is a topographical survey specialist and knows exactly what he is about. His advantages are (a) local knowledge, (:( specialist professional skills, and © access to additional data sources that he has managed to include in his mesh. So please don't put him down just because he is a 'commercial' rival. IMHO, Visual Flight is the ONLY properly flyable mesh for the UK, error-free and with a pretty good representation of features like our sea cliffs, rugged coastlines etc. that just cannot be matched by any mesh based on the general DEM sources.That doesn't mean that we don't appreciate your own work, Ray - of course we do. But maybe there is a good idea in this thread that would improve the flyability of most meshes. How about a series that uses an algorithm that allows the published MS elevation of each airfield to override the local DEM data and provides a graduated transition over a reasonable radius, using weighted averages, to blend back into the DEM data without a sharp mesa or pit. Needs a fair bit of number-crunching on the data, I know, but not a problem with modern computing power. As John has said, one of the things you would probably find from such an algorithm would be a general increase in the accuracy of the mesh anyway, because the airport elevation data may often be more accurate than the available DEM data (and not vice versa). I would subscribe to such a series very happily if you could do it. The other feature that would be attractive would be to add some cragginess back into the tops of elevated mountain peaks rather than the smooth rounded summits we tend to get. Again, that would probably be susceptible to a suitable number-crunching algorithm.Keep up the good workGerrish

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In Response to Gerrish;Dear Gerry - I can see your point - and of course I respect anybody opinion in full!Howewer - my point on the above post above - is that the simmers who post the picture - chooce a pretty flat area - where basically mesh is not visible - or have very little effect. that is all and it was not my intention to direct any attack to John.Another point - John is not a commercial rival - I design scenery just for fun - and care very little about the economical aspect of simming - which howewer most of the income which come from fsfreeware.com - goes back into it - and I've a full time job - outside to earn my living. I simply have fun with it!! and that is the way I like to keep it!I test both scenery - of course - only John sample and not the full Uk - and to be honest - all this honey which is described is simply not there - and resolution between Gaia mesh and John Uk mesh is of very little of difference - also remember - his scenery cost double price than mine!We all have different opinions - and be sure - some simmers switch from Gaia to John - and other switches from John uk mesh to Gaia - it all depends from personal point of view - - and it will be always wrong to thinks - of being fixed on anything - everything have somenthing different to offer - and simply bring different qualities - - and difects - - .Gerrish Wrote: Then Visual Flight came along and The latest Gaia Uk from Ray - did come out at the same time with John mesh - - I suspect Gerrish is reffering to the previous version of Uk mesh designed by Fsfreeware in the year 2001.Ray:-wave

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Hi RayYou're quite right Ray, I haven't purchased the Gaia UK mesh so perhaps I'm talking out of my *!?* and doing you an injustice. The previous version had put me off.I just didn't want you to give the wrong impression to anyone about John's product - it really is good! I'm not saying it's perfect, but it is a good enough model of the real world to be acceptable for decent FS flying without the type of errors that make one say 'oh no' and turn the mesh off again. You probably haven't looked in the right places. I'll also agree that I'm exagerating a bit about John's work if I say NO errors - I spotted some unfortunate islands at the bottom of pits in Loch Lomond, for example, but I suspect that's because the lake is at the wrong altitude, rather than a problem with the mesh. As there are no airfields on them, they can be ignored by looking away! It's when the approach to, and immediate surroundings of, an airfield are hopelessly wrong that we tend to get upset ...What about my suggestion of adding an airfield altitude blending algorithm to your methods for producing your new mesh - then none of us would have anything to complain about :-)CheersGerry

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No Problem Gerrish - Always take comments onboard - and understand what actualy can be done to improve!Of course - we are all working toward a better simulator - for all - no matter who does what - - and after all I believe the sim community can produce amazing software - - as you have done some very good work also!!Till the next - keep well -!!Ray:-beerchug

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GerrishGray wrote:"How about a series that uses an algorithm that allows the published MS elevation of each airfield to override the local DEM data and provides a graduated transition over a reasonable radius, using weighted averages, to blend back into the DEM data without a sharp mesa or pit."I have used FSTerrain by Martin Wright. This program will produce a 16 bit data image with the red & green bytes constituting the elevation. With care and without difficulty you can edit this image in a paint program and 'smooth' the mesa or pit out. I used Excel to convert the Lat/Lon to pixel x/y values on the image. Johan

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