<div class="gmail_quote">On Wed, Jan 11, 2012 at 3:03 PM, Frank Warmerdam <span dir="ltr"><<a href="mailto:warmerdam@pobox.com">warmerdam@pobox.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div class="im">On Wed, Jan 11, 2012 at 11:44 AM, Adam Stylinski <<a href="mailto:stylinae@mail.uc.edu">stylinae@mail.uc.edu</a>> wrote:<br>
> Like I mentioned in previous posts, other NAD83 geotagged las files produce<br>
> similar issues (for example fayetteville).<br>
<br>
</div>Adam,<br>
<br>
Where are these coming from? What are they generated with?<br>
<br>
You referred to "most of the data on the internet". What sort of<br>
sampling have you done?<br>
<br>
If the problem is very limited then I think it is better to fix<br>
the producer or work around the issue. If it is truely widespread<br>
then we might as well buckle under and make our consumer<br>
more robust.<br>
<div><div></div><div class="h5"><br>
Best regards,<br>
--<br>
---------------------------------------+--------------------------------------<br>
I set the clouds in motion - turn up | Frank Warmerdam, <a href="mailto:warmerdam@pobox.com">warmerdam@pobox.com</a><br>
light and sound - activate the windows | <a href="http://pobox.com/~warmerdam" target="_blank">http://pobox.com/~warmerdam</a><br>
and watch the world go round - Rush | Geospatial Software Developer<br>
<br>
</div></div></blockquote></div>Here is the one I was referring to:<div><a href="http://data.capcog.org/Information_Clearinghouse/data/LiDAR/Sample_LiDAR_LAS_File.zip">http://data.capcog.org/Information_Clearinghouse/data/LiDAR/Sample_LiDAR_LAS_File.zip</a></div>
<div>Many of the listed examples from lastool's compilation of ladar examples that use NAD83 have a different issue (not particular this one). This is all I can find that is freely available, anyway. The proprietary data that we have and I'm currently working with uses WGS84, so I cannot speak for other sources of data other than that which is available freely on the internet. </div>
<div><br></div><div>Here is what getProj4() and getWKT() return for these datasets:</div><div><br></div><div><div>GetProj4() = +proj=lcc +lat_1=28.38333333333333 +lat_2=30.28333333333334 +lat</div><div>27.83333333333333 +lon_0=-99 +x_0=1968500 +y_0=13123333.33333333 +datum=NAD83</div>
<div>nits=us-ft +no_defs</div><div>GetWKT() = COMPD_CS["unknown",</div><div> PROJCS["unnamed",</div><div> GEOGCS["NAD83",</div><div> DATUM["North_American_Datum_1983",</div>
<div> SPHEROID["GRS 1980",6378137,298.2572221010002,</div><div> AUTHORITY["EPSG","7019"]],</div><div> AUTHORITY["EPSG","6269"]],</div>
<div> PRIMEM["Greenwich",0],</div><div> UNIT["degree",0.0174532925199433],</div><div> AUTHORITY["EPSG","4269"]],</div><div> PROJECTION["Lambert_Conformal_Conic_2SP"],</div>
<div> PARAMETER["standard_parallel_1",28.38333333333333],</div><div> PARAMETER["standard_parallel_2",30.28333333333334],</div><div> PARAMETER["latitude_of_origin",27.83333333333333],</div>
<div> PARAMETER["central_meridian",-99],</div><div> PARAMETER["false_easting",6458320.416666665],</div><div> PARAMETER["false_northing",43055469.44444443],</div><div> UNIT["US survey foot",0.3048006096012192,</div>
<div> AUTHORITY["EPSG","9003"]],</div><div> AUTHORITY["EPSG","32140"]],</div><div> VERT_CS["NAVD88 - Geoid03 (Feet)",</div><div> VERT_DATUM["unknown",2005],</div>
<div> UNIT[,1,</div><div> AUTHORITY["EPSG","9003"]],</div><div> AXIS["Up",UP]]]</div></div><div><br></div><div>When I try to perform these projections with proj4, it gives me coordinates somewhere in the middle of the pacific. So no, the default parameters are not zero, but something is making the proj.4 library behave incorrectly. I apologize for assuming it was the same issue just because it was the same coordinate system. Still, there is a problem, and your help on why this is happening would be appreciated.</div>