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More terrain spot heights needed

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b5c830c40d747fdb5ae6278e1fc0a4e0?s=80&d=retro&r=g
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A wish...

I would like to see a lot more terrain spot heights shown on the main chart. Currently there are just a few, almost token, scattered spot heights shown and not nearly enough in dangerous hilly/mountainous areas.

Alan.

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5c1242ce1c84de60ae1ea618ae44df33?s=80&d=retro&r=g
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Hi Alan, 

I don't know if you followed https://easyvfr4.aero/community/feedback-on-features-and-functionalities/power-lines-a-bit-too-dominant/paged/3/ but upcoming version 4.0.831 will also have improved spot elevations for your area. Here are two screenshots : 

 

IMG 0039

 

IMG 0040

For this to work you will have to unselect  UK in menu->Downloads ->select Countries and then reselect again to get the latest datafiles.

 

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b5c830c40d747fdb5ae6278e1fc0a4e0?s=80&d=retro&r=g
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Great Rob, thanks for the info! ...That is a big improvement!

It has been quite a while coming but having more terrain spot heights just has to be a good thing from a safety viewpoint in mountainous/hilly areas. i have campaigned for this for a long time now.

 

Alan.

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Heli.Lamb
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that look loads better! nice one.

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edea88e0d5a8c51610f60ee8ff41c2e3?s=80&d=retro&r=g
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Any news about additional spot elevations in other countries, e.g. France? Thanks

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Currently GBR,AUT,CHE,FRA,ESP,BEL,DEU,IRL and NLD are rebuilt. ITA and GRC are currently working. If you uninstall and reinstall any of these countries you should see those spotelevations significantly improved. 

 

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Heli.Lamb
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I'm curious how the spot heights were chosen? Looking around the areas I know well I was trying to work out if they are representing the highest spot in an area or if they are denoting particularly prominent hills? There seem to be some large fells missed off that I would have expected but it might make sense based upon the rationale.

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Heli.Lamb
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I'd be happy to suggest additions/alternatives on the areas in the UK I know particularly well - although these aren't the areas I would need spot heights for when flying there 😉

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edea88e0d5a8c51610f60ee8ff41c2e3?s=80&d=retro&r=g
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Posted by: @andrew

I'm curious how the spot heights were chosen?

The spot heights we found are selected by topographic prominence. It is explained here: http://viewfinderpanoramas.org/prominence.html#def

If I understand it correctly, they are machine-selected spots that stick out from the surrounding elevation. I am sure it makes sense to "manually" add spots from personal knowledge of a certain area.

BTW, EVFR4 is really getting awesome.

BR

Albrecht

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Heli.Lamb
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@spornrad Thanks for the link. My computer tells me I've been on that site before and now I look around it I realise I know one of the authors so that might be why!

That site and those lists are written from a mountain-goes point of view with the relevant variable mountain prominence based upon re-ascent i.e. if moving between two fells, how much would you have to climb to get to the 2nd one. This is significant when running /walking as you can summit numerous mountains once "on the tops" without too much effort. Therefore, a mountain (even if small) with significant drop down to a saddle and climb back up will be regarded as "prominent".

For aviation, this is certainly not a bad metric to use and looking around the areas I know well it seems to work reasonably well but it has missed a few potentially important hills out (from a flying perspective).

A few examples where this method does not provide an additional spot height:

1. A long ridge of mountains with numerous tops along it but where the drop between them is minimal. The last one on the ridge might be a knarly pointy distinctive rock but as it's part of the "massive" it won't be included. (example)

2. Similar to the above, a large mountain massive, lots of tops, all higher than the surrounding valleys, all similar heights but no significant climb between them. This method only gives us 1 spot height. (example - with crashed Halifax)

3. A pair of fells with a reasonable distance between them. If you travel from the summit of the larger, you drop a significant distance and also travel a significant distance but then don't climb that much to the 2nd and so it won't be included. This 2nd might tower (relatively!) over the valley floor and might appear to the pilot as a hump sticking out into the valley. (example)

4. It doesn't give us any spot heights down in the valley or on the saddles between mountains. These are often handy when passing through a mountainous area low level with cloud on the tops. (dunmail raise, shap summit)

don't get me wrong, what we have now is brilliant!

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b5c830c40d747fdb5ae6278e1fc0a4e0?s=80&d=retro&r=g
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It is a big improvement that a lot more spot heights are now added to the charts, however a lot of them are only shown when really zoomed in to maybe 2miles or less which is not always convenient to zoom in to this level of magnitude.

I would like to see more of them shown when further zoomed out. Normal magnification I think is maybe 5miles (?) for most people when route planning and even when flying. It is at this 'normal' level of zoom that I would like to see more of the 'extra' added spot heights and not just when really closely zoomed in.

Alan.

   

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Posted by: @emailalanradford-co-uk

I would like to see more of them shown when further zoomed out. Normal magnification I think is maybe 5miles (?) for most people

I concur. For my taste the de-clutter is too aggressive here. When approaching a mountain area I would like to see more elevation numbers for selecting an appropriate route, already in an "overview" zoom level.

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Are we sure we want decluttering of spot elevations prohibited up to 5NM zoomlevel? Here is a screenshot how it would look arround LSMM compared with the current 2NM version

, many spotelevation labels clash with each other and IMHO the screen looks like its only about spotelevations and not about all the other aviation important stuff  ?

LSMM spotelevation declutter 5NM

This is the current 2NM version:

LSMM spotelevation declutter 2NM
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edea88e0d5a8c51610f60ee8ff41c2e3?s=80&d=retro&r=g
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@aeroea-changlian

For comparison I tried to snip the same area in the Swiss ICAO chart as compared to your cluttered screenshot:

image
image

Would there be a way to make de-clutter more smart?

Like: IF two elevation labels overlap, suppress the lower elevation label only?

 

 

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b5c830c40d747fdb5ae6278e1fc0a4e0?s=80&d=retro&r=g
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Hi Rob,

Yes it is all very well showing more spot heights at 2nm but no-one I know flies at 2nm zoom magnification! Most pilots fly at say 5nm zoom and that is when I personally want to see more spot heights.

Surely there is a compromise to be made here between the two images you show. What is shown at 5nm is not enough. If you look closely there is some serious terrain 10,000 ft+ in that 2nm pic and it is not marked at all at 5nm.  

Please don't take this the wrong way but I don't think you being situated in a flat country are not appreciating the seriousness of flying small aircraft in mountainous or hilly terrain.

Alan.

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edea88e0d5a8c51610f60ee8ff41c2e3?s=80&d=retro&r=g
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I believe in that area there are hardly any more aviation-relevant informations than the peak elevations... So yes, it should look like the screenshot (with all the elevations at 5 NM).

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Heli.Lamb
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I realise that I am in a rotary minority here but I'm more interested in the topography of the valleys either side of the spot heights with a view to flying down them if necessary and also use the spot heights to decide on the risk/advantage of doing so. It seems to me that the EVFR views either with or without the numbers are miles better than the SwissICAO chart! A cluttered map does give a good impression of the size of the hills but it does mask the valleys a little.

As I mentioned in my previous post, I would find spot heights of the valleys and passes equally as useful as the tops so if we are going to increase 'clutter' I'd find it much more useful to be this data - like how the NZ maps show saddles/passes for example.

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Posted by: @spornrad

For comparison I tried to snip the same area in the Swiss ICAO chart as compared to your cluttered screenshot:

When doing that, the ICAO chart looks much closer to the current (decluttered) 5NM scale then the non-decluttered example I provided:

 

image
image

 

I'm really convinced nobody is going to read all those cluttering numbers while flying. Its a total waste of valuable screen space, and features like Relative terrain (when flying) and valley terrain (when planning) provide the terrain dangers and possible escapes in a "glance of the eye" without having to read tens of different overlapping numbers on a screen. But I know, me as flatlander should keep my mouth shut about what helped me personally the most in those few moments I had a fight with Terrain and Weather at the same time 😉

Decluttering is already done fairly smart, though when checking all highest elevation numbers on the ICAO chart with the highest elevation numbers on the EV4 chart using the same scale there is a little room for improvement. I'll have a look at that.

Just out of curiosity, I also wonder why on the ICAO chart there are two "purple bold" elevations (14022 and 13642 for Finsteraarhorn and Jungfrau) ? 

 

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Posted by: @aeroea-changlian

Just out of curiosity, I also wonder why on the ICAO chart there are two "purple bold" elevations (14022 and 13642 for Finsteraarhorn and Jungfrau) ? 

Likely the largest/most famous in the area. I've come across fell tops being labelled like this in various countries. Some of them have the name of the largest as well as the height and all the surrounding fells just have the spot height. It's useful to know where the "top" of the mountain massive is in amongst the mass of topo shading and spot heights.

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Heli.Lamb
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Posted by: @aeroea-changlian

features like Relative terrain (when flying) and valley terrain (when planning) provide the terrain dangers and possible escapes in a "glance of the eye" without having to read tens of different overlapping numbers on a screen

Agreed, I use that feature a lot. Common for me is cloud base at 2000', tops generally between 2000 and 3000 and so me in the valley at 1500 aiming for a saddle. Relative terrain is great and then aim for the bright smiley face at the end of the valley and hope it's still there when you get to it!

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Heli.Lamb
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The NZ mapping is amongst the best for mountains that I have ever used.

Key features are:

  1. Spot heights at either end of a range or ridge line no matter how small the relative height/prominence.
  2. Spot heights sometimes without names to aid clarity
  3. Some bold or boxed spot heights to denote the highest in the area or a particularly obvious mountain.
  4. Some valley spot heights
  5. Mountain passes labelled and also named with a spot height.
  6. Clear shading
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