[Proj] cs2cs returns error then 0s with datum conversion

Eric Miller EMiller at dfg.ca.gov
Wed Jan 12 15:20:26 PST 2011


Well, the first question is whether cs2cs would even be considered NADCON.  I would guess not unless NGS has a process for certifying implementations and cs2cs was certified.

Still, if cs2cs (or really, the underlying grid handling) were to support the las/los file format directly, then at least it's be a trivial matter to drop new files into an installation.  No need to mess with transforming the files.  I guess Frank already did that work for GDAL (http://svn.osgeo.org/gdal/trunk/gdal/frmts/raw/loslasdataset.cpp) but it can't just be copied to PROJ.4.

>>> On 1/12/2011 at 12:04 PM, Clifford J Mugnier <cjmce at lsu.edu> wrote:
> NADCON is a U.S. Federal standard.  Converting its data files to NTv2 format 
> would be useless for applications within the U.S. as it would no longer be 
> compliant with the Federal Register mandate.  
>  
> The converse would likely apply to some other countries, including Canada 
> and the Union of South Africa.  Other countries may have not (yet) enacted 
> legislation that codifies the specific methodology, but I have never seen a 
> study of such a topic.
>  
> When working with National Coordinate Systems and Reference Frames, one can 
> get into trouble quickly through ignorance of local laws.
>  
> Clifford J. Mugnier, C.P., C.M.S.
> Chief of Geodesy,
> Center for GeoInformatics
> Department of Civil Engineering 
> Patrick F. Taylor Hall 3223A
> LOUISIANA STATE UNIVERSITY 
> Baton Rouge, LA  70803
> Voice and Facsimile:  (225) 578-8536 [Academic] 
> Voice and Facsimile:  (225) 578-4578 [Research] 
> Cell: (225) 328-8975 [Academic & Research]
> Honorary Life Member of the 
> Louisiana Society of Professional Surveyors 
> Fellow Emeritus of the ASPRS 
> Member of the Americas Petroleum Survey Group
> 
> 
> ________________________________
> 
> From: proj-bounces at lists.maptools.org on behalf of Frank Warmerdam
> Sent: Wed 12-Jan-11 13:25
> To: Mikael Rittri
> Cc: PROJ.4 and general Projections Discussions
> Subject: Re: [Proj] cs2cs returns error then 0s with datum conversion
> 
> 
> 
> On 11-01-12 04:31 AM, Mikael Rittri wrote:
>> Eric wrote:
>>
>>> Maybe someday an enterprising soul will convert cs2cs to use National 
> Geodetic Survey's
>>> current correction file format directly...
>>
>> Or maybe Frank would be willing to convert these files (conus, alaska, etc.)
>> to the NTv2 format (and publish them), since he has already developed tools
>> for that conversion, and since cs2cs already understands that format.
>>
>> (See http://lists.maptools.org/pipermail/proj/2010-August/005330.html )
>>
>> Of course, this would help only if the NTv2 format is unaffected by
>> the 32-bit/64-bit issue.  I don't know for certain if that's true.
> 
> Folks,
> 
> The NTv2 format is not affected by structure packing, byte order or word
> size and is a good candidate for a cross platform replacement for the
> binary format into which the conus and related files are currently 
> translated.
> Unfortunately my work in GDAL with NTv2 format does not include support for
> the .lla format yet, but I would love to replace it.  I think I have seen
> the same data in .los/.las format, so perhaps I could just find and 
> translate
> those.  It would be wonderful to cleanup this aspect of proj.4 datum 
> handling.
> 
> Best regards,
> --
> ---------------------------------------+--------------------------------------
> I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com 
> light and sound - activate the windows | http://pobox.com/~warmerdam 
> and watch the world go round - Rush    | Geospatial Programmer for Rent
> 
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