NZ DEM (elevation) Files

[wildwanderer]

Does anyone know where I can get high quality DEM files for NZ south island?

The nz govt site has them in geo tiff but Ive no idea how to convert to hgt.

I'm after 1 sec or better accuracy.

[keithy]

I have previously download the dem data from NASA/USGS. https://earthexplorer.usgs.gov/ I think it was also in geotiff if you got individual files which you need to convert to hgt. Although it looks like you can get some hgt files zipped. I haven't used them since 2016. https://e4ftl01.cr.usgs.gov/MEASURES/SRTMGL1.003/ you need to make an account to download.

For oruxmaps on my devices the 1 arc sec hgt is about 25Mb each hgt file so I stick with the 3 arc sec about 2.7Mb each file

Jonathan de Ferranti has made some corrections to the 3 arc sec SRTM http://viewfinderpanoramas.org/Coverage ... s_org3.htm which you can download in hgt. He has been slowly adding 1 arc sec dem but mainly in Europe. I've currently got his 3 arc sec files for NZ on my phone and tablet.

Also there was meant to be a reprocessed SRTM dem by NASA (NASADEM) was meant to be released soon but I haven't been following it.

[michael_p]

Converter here: https://mygeodata.cloud/converter/geotiff-to-hgt . Never used it so not sure how good or bad it is, and free service is limited (check the plans page for details).

Cheers,
Michael.

[wildwanderer]

Cheers Guys,

I'l have a look into the earth explorer site.

Unfortunately the mygeodata tool is limited to 5mb exports without paying. Which isnt large enough for 1 sec 25mb HGT files

[tastrax]

Any of these help?

https://data.linz.govt.nz/search/?q=dem

[tastrax]

8M model - about 16gb - https://data.linz.govt.nz/layer/51768-n ... odel-2012/

[wildwanderer]

8M model - about 16gb - https://data.linz.govt.nz/layer/51768-n ... odel-2012/

These are great except they are only available in tiff. I need a way to convert to HGT so they are readable on my map app.

[michael_p]

Unfortunately the mygeodata tool is limited to 5mb exports without paying. Which isnt large enough for 1 sec 25mb HGT files

Thank you. Handy to know how limited that "free" service is.

Did a quick search and apparently gdal_translate can convert geotiff to hgt. Info on Gdal: https://www.gdal.org/ . Have a look at the answer to this question: https://gis.stackexchange.com/questions ... iff-to-dem .

Michael.

[tastrax]

You can also use QGIS processing to translate the files (which uses the above GDAL process)