Dogs Of War Vu

Network of Friends => Tacview => Real-Life => Topic started by: pdmarsh on August 07, 2017, 02:05:56 PM

Title: SRTM Data
Post by: pdmarsh on August 07, 2017, 02:05:56 PM
From what I can tell, the data from Jonathan de Ferranti's web site is SRTM3 level resolution.  However, the notes say that this has been down-sampled from 1" data.  If you download his data, do you still have to download SRTM1 data to get the better resolution?

Thanks,
Paul
Title: Re: SRTM Data
Post by: Vyrtuoz on August 08, 2017, 02:33:15 PM
If the data you are giving to Tacview are in a medium resolution (in that case, SRTM3), Tacview will display SRTM3 resolution on screen. There is no way downsampled data can be upsampled back to their original SRTM1 resolution. Note that, with SRTM3 data, you will still see smooth triangles in Tacview because data will be cleanly interpolated.

I have found a website which offers free worldwide SRTM1 data:
https://search.earthdata.nasa.gov/search?p=C1000000240-LPDAAC_ECS&m=38.3965!8.438!2!1!0!&q=SRTMGL1+V003&sb=8.438%2C33.724%2C30.938%2C43.069

It is painful to use, but it works and the registration is free.

Now, during my experimentations, with X-Plane for example, I have noticed that more is not always better (to quote “Oscar Pilote” from OrthoXP). I find Jonathan SRTM3 data cleaner and more consistent than higher resolution SRTM1 terrains.
Title: Re: SRTM Data
Post by: pdmarsh on August 09, 2017, 01:14:29 PM
Thanks Frantz.  I agree--I don't see a lot of difference going from Jonathan's SRTM3 data to SRTM1.

Paul