[Proj] ERROR 6: No translation for Lambert ConformalConic to PROJ.4 format is known.

[Clifford J Mugnier]

Actually, American Samoa has a single standard parallel; it is a true Tangent Case of the Lambert Conformal Conic.  
 
On the other hand, the British Definition only lists the Latitude of Origin along with the Scale Factor at Origin.  For the British Definition, there's only "one standard parallel" according to the ignorant programmers that can't spell Geodesy with their eyes closed, but the two standard parallel case in the British Definition also lists the Scale Factor at Origin as being less than one (0.9999xxxxxxx).  
 
For American Samoa, in the British Definition, the Scale Factor at Origin is equal to unity (1.0).
 
>From whence does 1SP and 2SP come from?  Ignorance.
 
The math to convert from one definition to the other is in the Sixth Edition of the Manual of Photogrammetry, Chapter 3.
 
C. Mugnier
LSU

________________________________

From: proj-bounces at lists.maptools.org on behalf of Eric Miller
Sent: Wed 01-Apr-09 13:06
To: proj at lists.maptools.org
Subject: Re: [Proj] ERROR 6: No translation for Lambert ConformalConic toPROJ.4 format is known.



>>> On 4/1/2009 at 9:19 AM, Hermann Peifer <peifer at gmx.eu> wrote:
> Frank Warmerdam wrote:
>> Hermann Peifer wrote:
>>> Hi,
>>>
>>> Is this simply yet another unsupported projection, or could
something
>>> else be wrong?
>> ...
>>>      PROJECTION["Lambert Conformal Conic"],
>>
>> Hermann,
>>
>> What is the source of this WKT?  Oracle?  GeoTools?  The PROJECTION
keyword
>> does not match my expectations nor the specification on which WKT
is
>> based which I believe included an example of LCC.  The keyword
should be
>> Lambert_Conformal_Conic_1SP or Lambert_Conformal_Conic_2SP.
>>
>
> We receive shapefile deliveries from a network of several hundred
data
> providers across more than 30 European countries. I do not know what

> kind of shapefile-generating systems they use at home. I will ask the

> French provider of this particular shapefile. More news soon.
>

Frank,

ArcGIS (9.1 at least) has "Lambert_Conformal_Conic" for U.S. state
plane definitions and others.  All of the definitions I looked at had
two standard parallels.

I'm not sure where the 1SP and 2SP stuff comes from.  The Simple
Features Spec. for OLE (1.1) appendix 4-6 only lists "Lambert conformal
conic."  So, the software in question is using the listed name.  The
practice of replacing spaces with underscores in never mentioned.  The
examples use underscores but the list of supported projections does not
have underscores and there is no direction that underscores should be
used or supported.

Thus, I think a robust WKT interpreter must accept projection names
with or without underscores and with or without the _1SP or _2SP
refinements. (If needed, it must look at the parameters to
disambiguate.)  Additionally, there probably needs to be handling for
hyphens (missing or present) and accents/non-ascii (missing, present or
alternate spelling).  Is it "Plate-Carée" or "Plate_Caree" or
"Plate-Carree" or "Plate_Carree" or ... ?  Only the first version is
listed in appendix 4-6.  Perhaps it's easiest just to maintain a table
of synonyms?


--

Eric G. Miller
Staff Programmer
CA Dept. of Fish & Game

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