Re: utm

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Re: utm

Pascal Brisset-3
Hi Martin,

UTM coordinates are not used for SRTM: the SRTM files are aligned of
geographic (lat, long) coordinates.
Unfortunately, data are missing for Norway, north of latitude 60° (see
for example,
http://www.caf.dlr.de/dlr/presse/archiv/sonderseiten/srtm/coverage.htm).

But, ..., I found another source

    http://www.viewfinderpanoramas.org/dem3.html

where the provided P31.zip contains the desired N60E005.hgt  (now
available from
www.recherche.enac.fr/~brisset/N60E005.hgt.bz2 )

It seems almost correct (well the sea surface is about 15m in the
harbour !) and anyway should be enough for
the GCS.

--Pascal

PS: By the way, some other awfull problems are hidden behind UTM
coordinates usage in Paparazzi ...


Martin Mueller wrote:

> Hi Pascal,
>
> there is some strange thing we saw. We did some simulations for eastern Norway where the meteo guys from University of Bergen live. They are in Hildesheim right now and think about using Paparazzi for measurement (we met Prof. Reuder outside the Braunschweig building before going to DLR last summer, he started the EU COST paper work).
>
> We did a flight plan for Bergen (N 60.382817 E 5.330858) and loaded the SRTM. There is no SRTM info in the GCS for Bergen area, it shows 32768m. If you turn on the UTM grid on in GCS and walk south with the mouse, it will appear at some UTM grid border. I remembered some strange UTM behaviour and saw that http://www.dmap.co.uk/utmworld.htm
>
> In eastern Norway and Svalbard (which is intersting to them...) the grid is different http://www.fmnh.helsinki.fi/english/botany/afe/map/utm.htm
>
> Most UTM converters are not aware of that and give grid 31 for the region. This one seems to do it http://www.dmap.co.uk/ll2tm.htm If you enter values around the borders (e.g. N 56'0 E 5'0 and 55'59 E 5'0) you will have another grid and a different eastern reading as it starts at a different longitude.
>
> Could it be that this utm "anomaly" makes the SRTM go away?
>
> See you,
> Martin
> _______________________________________________________________
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>  



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Re: utm

Martin Mueller
Hi Pascal,

thanks for the fast reply!

> UTM coordinates are not used for SRTM: the SRTM files are aligned of
> geographic (lat, long) coordinates.
> Unfortunately, data are missing for Norway, north of latitude 60° (see
> for example,
> http://www.caf.dlr.de/dlr/presse/archiv/sonderseiten/srtm/coverage.htm).
>
> But, ..., I found another source
>
>     http://www.viewfinderpanoramas.org/dem3.html
>
> where the provided P31.zip contains the desired N60E005.hgt  (now
> available from
> www.recherche.enac.fr/~brisset/N60E005.hgt.bz2 )
 >
> It seems almost correct (well the sea surface is about 15m in the
> harbour !) and anyway should be enough for
> the GCS.

Thanks! Will get that when back home.

> PS: By the way, some other awfull problems are hidden behind UTM
> coordinates usage in Paparazzi ...

You can not cross UTM zone borders and not navigate in the "special" "bigger" UTM zones in Norway and north?

See you,
Martin

_______________________________________________________________
SMS schreiben mit WEB.DE FreeMail - einfach, schnell und
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