#122 SRTM-1 Support

[Wolfgang ch]

Feature Request from
https://sourceforge.net/p/mytourbook/discussion/622811/thread/03a300d7/?limit=25#723f

This information is provided by Alfred Barten

Man könnte MT so erweitern, dass es aus den "Schichten" SRTM-3 /SRTM-1 auswählt, je nach Größe der Karte oder explizit über Bedienelemente.

MT verwendet momentan nur Format HGT für SRTM-3. USGS veröffentlicht drei Formate für SRTM-1, aber HGT ist nicht dabei. Eins der Formate ist DTED, das ist zwar ähnlich, aber man müsste es konvertieren oder eine neue Lesemethode schreiben. Zum Lesen von HGT für SRTM-1 wäre das aber auch der Fall.

Für den Download der USGS-Daten braucht man außerdem ein Login.

[Mike Rhosoft]

I obtained the HGT-files using a converter:

• the Login at USGS-earthexplorer was for free
• I downloaded the elevation-data as BIL-files
• than I used BILxSRTM-converter (http://www.mediafire.com/download/vuby9jvdk8r7drm/BILxSRTM.zip) to convert the files to HGT-format

[Alfred Barten]

In my own private application I use SRTM-1 for years. For elevation backgrounds it of course is more detailed, but for calculation of ascent sums of activities I use SRTM-3, not SRTM-1. SRTM-3 with a little smoothing gives the best results. I add ascents if they are 5m or more (configurable). SRTM-1 with the same smoothing results in accent sums which are much to big, e.g. for a ride with 1000m ascent it results in ~1700m. SRTM-3 has more "natural" smoothing which at first sounds contradictory but in practice is better for calculation of ascents. At least my experience! ;)

[Wolfgang ch]

This feature is available in MT 22.2

[Wolfgang ch]

You can switch between SRTM 1 and SRTM 3

SRTM 1

SRTM 3

[Wolfgang ch]

Postponed the feature to switch between SRTM 1 + 3 to MT version after 22.2, there were too many code changes which could be dangerous for MT 22.2

https://github.com/mytourbook/mytourbook/issues/469

[Mick]

Noooooooooooooo 😭

[Wolfgang ch]

It's only the UI, to switch between SRTM 1 and SRTM3, which is postponed.

In the next version 22.2 (tomorrow), SRTM 1 is used/displayed when these data are available

[Mick]

Yeeeeeeeeees 😊 Thanks for all job done