Nikos Alexandris <[email protected]> writes: > * Nikos Alexandris <[email protected]> [2017-11-21 10:25:42 +0100]: > >>Dear list, can GDAL handle the following exercise? >> >>Of interest is the Mean Sea Level, based on NASA’s SRTM. I am new in this >>topic. Is the following equation correct? >> >>SRTM(MSL) = SRTM(WGS84) - MSL(WGS84) [*] > > Here https://gitlab.com/NikosAlexandris/mean-sea-level the exercise I > did back then. I never got to continue on this. > > The last three days of the past week, I've been an observer of a > "geomorphometry" meeting. So, I asked someone knowledgeable to get some > feedback. It seems it's on the right track. Perhaps it'll be of > interest to some people.
I would caution that the phrase "mean sea level" is potentially confusing. It was used to refer to what was thought to be an equipotential surface that lead to the Sea Level Datum of 1929, and later called NGVD 1929 when it was realized that it was not actually an equipotential surface. I think you are perhaps talking about an actual mean of sea levels over some area, where the levels are expressed relative to some particular geoid. But that's not clearly inferrable from the words, and I think it would be helpful to be painfully pedenatically precise about terms. The phrase "SRTM(WGS84)" does not clearly distinguish between WGS84 ellipsoidal height, apparently the native measurement and height relative to the WGS84 geoid. I also have a hard time understanding what "MSL(WGS84)" is. _______________________________________________ gdal-dev mailing list [email protected] https://lists.osgeo.org/mailman/listinfo/gdal-dev
