[marcuskiwi]

I am trying to build a route from Westport to Greymouth in the South Island of New Zealand and have hit a snag. I have downloaded all HGT files required from USGS.gov./SRTM3 site but Westport S41E171.HGT is not available which the Route Editor is looking for.
I then tried LINZ New Zealand and I can download the Westport area but only in TIFF or ASC format. So my main question is can anyone suggest a FREE program to convert TIFF etc to HGT
Mike

[Goku]

I think it's missing because it is middle of the ocean - so no data.
Are you sure that your tile is in the right position? (check what is on the OSM map, or Google Maps).

.. edit, ok I see that Westport is right in the corner of S41E171 tile ...

Some indian user found solution how to convert tiff to hgt and posted it somewhere on this forum.

[marcuskiwi]

Goku, on 27 November 2017 - 01:46 PM, said:

I think it's missing because it is middle of the ocean - so no data.
Are you sure that your tile is in the right position? (check what is on the OSM map, or Google Maps).

.. edit, ok I see that Westport is right in the corner of S41E171 tile ...

Some indian user found solution how to convert tiff to hgt and posted it somewhere on this forum.

Thanks Goku I will check it out
Mike

Edit: I found the solution but I must admit I could not work out the system at all. It was all too much for my 77 year old brain. I will have to start my route from somewhere other than Westport which is a pity.

[strawberryfield]

marcuskiwi, on 27 November 2017 - 12:00 PM, said:

So my main question is can anyone suggest a FREE program to convert TIFF etc to HGT
Mike

I can suggest Microdem

Remember that .hgt is a dumb format, so the ability to read (geo)tiff from the editor will be appreciated.

[Goku]

Where you found the tiff files?

[Goku]

I think you found a bug in TSRE. No one used geo tools in the south earlier.

Westport is -41.75,171.59 and TSRE asks for tile S41E171 .. but S41E171 is middle of the sea. TSRE should ask for S42E171.
https://e4ftl01.cr.u...1.SRTMGL1.2.jpg

[marcuskiwi]

Goku, on 28 November 2017 - 10:53 AM, said:

I think you found a bug in TSRE. No one used geo tools in the south earlier.

Westport is -41.75,171.59 and TSRE asks for tile S41E171 .. but S41E171 is middle of the sea. TSRE should ask for S42E171.
https://e4ftl01.cr.u...1.SRTMGL1.2.jpg

That would solve all my problems if you can somehow make TSRE ask for S42E171 instead of S41E171
Mike

[strawberryfield]

Goku, on 28 November 2017 - 10:38 AM, said:

Where you found the tiff files?

I use this tool to download 20m grid data for Italy: http://www.trainsimh...ad.php?did=1340
But you can download data for the whole world here, there are other sites like this with more detailed data.

If you want an example how to manage GeoTiff files in c# please take a look to my tool.

[marcuskiwi]

Thanks for the info but Goku has now fixed TSRE to read correct New Zealand HGT files so I no longer need to worry about TIFF files

Mike

[Genma Saotome]

There are two issues at play here -- the file format that holds the DEM data and the resolution of the DEM data itself.

IMO using one and only one file format is basically unacceptable because it will cut out more recent DEM data (higher resolutions). Both IMG and GeoTif are widely available and often the only high res data available are in those formats. Good GIS tools, such as QGIS, don't provide for .hgt format.

WRT resolution the US is moving towards 1m resolution. 30M is available for almost all of the country. TSRE needs to provide for multiple formats and a variety of resolutions so it meets the needs of a wide range of end users.