phpmapscript projection problem(?)

Andreas T haristeas at GMAIL.COM
Mon Dec 4 16:52:53 EST 2006


Hi!

I have been trying to reproject a point from one projection to an other with
phpmapscript and its projection object (with the PROJ.4 that is enhanced
with phpmapscript). I am using phpmapscript_48.dll (i supose it refers to
version 4.8...).

The original projection of the point that I am trying to reproject is a
greek projection system called "TM3". It has the following attributes:

   - projection = *Tranvserse Mercator 3o*
   - ellpisoid = bessel
   - lon0 = 23ο42' 58''.815
   - lat0 = 34
   - towgs84 = DX=456.39, DY=372.62, DZ=496,82, DangleX=0, DangleY=0,
   DangleZ=0.000363, ppm=0.0000159
   - False E = 200000
   - False N = 0
   - Ellipse big axis = 6377397.155m
   - 1/f = 1/299.1528128
   - k0 = 0.9999
   - units = m

The second projection is the universal WGS84 (LAT/LONG)

The point's initial values are:
X = 134216
Y = 731046
The correct tranformation should have give us:
lon=22.562799
lat=40.3511194

Though I keep taking something like:
lon=22.9206930
lat=40.5838561
The diference seems to be small with naked eye, though it hundreds of
meters...

I have tryed (believe me) with a number of different ways to export the
right lat/long though the result came again and again the same. I provide
the code that I used:
[CODE]
$projInObj = ms_newprojectionobj("proj =tmerc,ellps=bessel,towgs84=456.39,
372.62,496,82,0,0d00m00363s,0.0000159,".
"lat_0=34d0m0s,lon_0=23d42m58815s,x_0=200000,units=m,k=0.9999,a=6378137,rf=
298.25722101");

$projOutObj=ms_newprojectionobj("proj=latlong,ellps=WGS84,DATUM=WGS84");

$myshape = ms_newpointobj();
$myshape->setXY(134216, 731046);

$myshape->project($projOutObj, $projInObj);

print_r($myshape);
[/CODE]

Can you please help me understand why I keep getting bad results? Is it
something that I am doing wrong? Does it have to do with a PROJ problem?

Thanks for the time
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