Selecting the correct Dem??

[Basherz]

Can anyone give me an easy, or reliable method, for selecting the correct DEM (hgt) files. This seems a very hit or miss affair.

Thank you.

[choccy]

UK 1 degree map grid for 90M DEM Route Builders [161124 bytes] - UK_1deg_grid.zip File ID: 7390 Date: 03 Dec 2003 - 1761 Downloads

The above should help, but I don't find the grid that easy to follow. It's only for the UK though. Mark

[Basherz]

Thank you mark, I can certainly use this. Unfortunately the Dem I am currently looking for is European, and in an area I am not familiar with.

[bigvern]

I have a Collins World Atlas which is a useful guide. Either that, or if you're using Google Earth for markers that gives you the Lat/Lon you need. There's a little freeware utility called 3DEM which allows you to view hgt files and this should indicate if you have the right segment. If in doubt, just place the adjacent DEM sections in the KRS DEM folder to cover yourself.

[Basherz]

Thanks Vern, I'll give this a try.

[Ryosuke]

you can activate a grid overlay in google earth under "view" and set the display to "degree" under "options."

then look for the place you want DEM data from in google earth and note the north or south and east or west degrees (works best when the zoom height is around 1000 kms.)

berlin for example is in the rectangle 52° north and 13° east.

on the SRTM server then look for the file "N52E013.hgt.zip"

[balloonist2009]

Hi there the only thing wrong with the DEM Dater is it is out of date and the route you are working on eg oxford and paddington route when you push T the track will be covered. This is becuse the hgt file's you download for your route are right but theay are set at the wrong hight and will put your marker's out ie when you lay your track it will put you through a hill because the long\lat from googel earth is diffrent to the hgt file's i have emailed about this to the site and thay have said that the hgt file's will not match googel earth as googel earth is up dated and the hgt file's are not.

[Basherz]

Thanks very much guys, I think that between you all, I now have the answer.

[Horgy]

Hi there the only thing wrong with the DEM Dater is it is out of date and the route you are working on eg oxford and paddington route when you push T the track will be covered. This is becuse the hgt file's you download for your route are right but theay are set at the wrong hight and will put your marker's out ie when you lay your track it will put you through a hill because the long\lat from googel earth is diffrent to the hgt file's i have emailed about this to the site and thay have said that the hgt file's will not match googel earth as googel earth is up dated and the hgt file's are not.

Can you take a deep breath, and say this again? My DEM works fine - the ground doesn't get resited like track and infrastructure does!

Horgy

[arabiandisco]

Hi there the only thing wrong with the DEM Dater is it is out of date and the route you are working on eg oxford and paddington route when you push T the track will be covered. This is becuse the hgt file's you download for your route are right but theay are set at the wrong hight and will put your marker's out ie when you lay your track it will put you through a hill because the long\lat from googel earth is diffrent to the hgt file's i have emailed about this to the site and thay have said that the hgt file's will not match googel earth as googel earth is up dated and the hgt file's are not.

Can you take a deep breath, and say this again? My DEM works fine - the ground doesn't get resited like track and infrastructure does!

Horgy

I think he's expecting the DEM to include embankments and cuttings...

[bigvern]

Don't think even the 30m US DEM has cuttings and embankments drawn ready made! For that matter, most DEM doesn't reflect the correct depth of lakes, coastlines etc. either, so some hand bashing of the terrain to Google Earth markers is inevitable.

[Horgy]

I know most DEM is corrected to edit man made features out in some cases. I have some exceptionally high resolution DEM data (in the region of 25m res) for the UK which doesn't have it in - I am yet to find a way of importing it into the sim though :/

Horgy