[Proj] Re: To handle geographic info from HDF5 formated Satellite
agerturk at gmail.com
Thu May 8 09:51:49 EDT 2008
Frank Warmerdam <warmerdam <at> pobox.com> writes:
> Aydin wrote:
> > Frank,
> > Thank you for response.
> > if I use your suggestion, for example pixel (1000,1000);
> > longitude = -25 + 0.560648 * 1000 = 5581.48
> > latitude = 75 - 0.560648 * 1000 = -5531.48
> > So, it is not possible.
> > I do not have problem converting projected space to geographic space using
> > proj lib. My problem is how can calculate the distance from the corner
> > below parameters than I can convert those to lat/lon.
> I stand corrected - the pixel size turns out to be in km not decimal degrees.
> So you will have to offset from the top left corner using:
> x (easting) = -2782987.27 + 560.648 * pixel
> y (northing) = 8348961.81 - 560.648 * line
> Then reproject that point back to long/lat using
> proj -I +proj=eqc +lat_ts=0 +lon_0=0.000000 +ellps=WGS84
> Good luck,
Thank you very much that you pay time for me.
Unfortunately, it does not work. Let me show.
We have centre lon/lat values which are: lon=9.719999, lat=50.47374
Centre point pixel value are XCenter=2250, Ycenter=1583.
x (2250) = -2783 + 2250*0.560648 = -1521.5 km.
y (1583) = 8349 - 1583*0.5621554 = 7459 km.
When get the lon/lat using proj
lon = -13.667867
lat = 67.006235
which are not true.
It is realy diffcult to solve this porblem at least for me.
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