New GPS for Old

Thanks for the information Phil. Went to the site,
downloaded the app and then started to read the site stuff.
Anyway after a couple of hours of thinking I knew something
only to find I didn't really understand what was written I
loaded up the app and had a go. Using the given inputs it
certainly does a good job of getting shut of the anomalies
that is in the SRTM data.

Mike Mason

"Phil Cook" <[email hidden]>
wrote in message
"]news:[email hidden]...

Quoted message said:

Those of us with old GPS equipment that doesn't log
altitude, or newer equipment that produces a log profile
like the Cuillin when strolling over the downs, might like
to know that by adding Ozi-3D and SRTM data to Oziexplorer
you can get height profiles from 2-D GPS tracklogs.

First install Ozi-3D (the demo does all you will need)
then get the SRTM (Shuttle Radar Topography Mission)
height data, there is a link and instructions on the Ozi-
3D page. oziexplorer.comoziexplorer.comOpen ↗

Then in Ozi import your track and in Track Control click
the [+V] (More Options...) button and select Track
Profile. Bingo. To save the altitude to the tracklog
select Track List in Track Control, select all the points
then click the [.V] (Change Properties for All Selected
Track Points) button and select Add Altitude to Selected
Trackpoints, then Save Selected Trackpoints To File.

The SRTM data is sampled at 3 arc second intervals and is
pretty accurate compared to GPS altitude, though there are
voids caused by scattering of the radar by water, snow or
steep slopes. These are quite bad in Scotland where you
end up dirty great big holes in areas like the Cuillin and
Torridon. However these can be fixed with Blackart
terrainmap.comrm38.htmlOpen ↗

See p-t-cook.freeserve.co.ukskyeOpen ↗
holes.htm for an example.

Now what shall I spend the money I saved by not buying a
new GPS on?
--
Phil Cook looking north over the park to the "Westminster
Gasworks"