[MetaCRS] failed epsg wkt (geotools)

[Christopher Schmidt]

On Tue, Dec 16, 2008 at 11:41:17AM +0100, Mikael Rittri wrote:
> Thanks for your efforts. 
> But may I call attention to eleven coord. ref. systems that are wrong 
> on SpatialReference.org. (I am not sure what causes the errors.) 

Mikael,

Loading data from the EPSG database is a tedious and confounding
process, with many different pieces installed. :) These reports are
useful on their own: I will attempt to help make sure they get to the
right people to fix them in the software chains that produce them.

Thank you for your feedback on both of these and please feel free to
offer anymore that you find which are incorrect. We will work on
improving these.


> First: 
> 
> * EPSG:3388, Pulkovo 1942 / Caspian Sea Mercator
> 
> According to EPSG, the projection method is "Mercator (2SP)", coord op
> method 9805, with a standard parallel at 42°N.  But on
> SpatialReference.org, the projection method in OGC WKT is given as
> "Mercator_1SP", and the standard parallel is absent from the
> parameters.
> 
> The other ten that are wrong are: 
> 
> * EPSG:2056,  "CH1903+ / LV95"
> * EPSG:2057,  "Rassadiran / Nakhl e Taqi"
> * EPSG:21780, "Bern 1898 (Bern) / LV03C"
> * EPSG:21781, "CH1903 / LV03"
> * EPSG:23700, "HD72 / EOV"
> * EPSG:29700, "Tananarive (Paris) / Laborde Grid",
> * EPSG:29702, "Tananarive (Paris) / Laborde Grid approximation"
> * EPSG:29871, "Timbalai 1948 / RSO Borneo (ch)"
> * EPSG:29872, "Timbalai 1948 / RSO Borneo (ft)"
> * EPSG:29873, "Timbalai 1948 / RSO Borneo (m)"
> 
> According to EPSG, all these use the projection method "Oblique
> Mercator", coord op method 9815.  But on SpatialReference.org, these
> ten CRSs are given the projection method "Hotine_Oblique_Mercator",
> which is a different method (coord op method 9812).   
> 
> It is true that each instance of "Oblique Mercator" can be
> reformulated as an instance of "Hotine Oblique Mercator", but this
> requires that you adjust the False Easting and False Northing, which
> has not been done.  EPSG Guidance Note 7.2 gives the example of
> "Timbalai 1948 / R.S.O. Borneo (m)",
> which has 
>     Easting at projection centre  (EC) = 590476.87 metres
>     Northing at projection centre (NC) = 442857.65 metres
> 
> This can be reformulated as an instance of "Hotine Oblique Mercator", but only if you adjust
> these parameters to 
>     False easting (FE) = 0.0 metres
>     False northing (FN) = 0.0 metres
> 
> Note also that some CRSs in the ESPG database do use "Hotine Oblique
> Mercator", so it is no solution to just replace
> "Hotine_Oblique_Mercator" by "Oblique_Mercator" everywhere.  The two
> coord op methods must be distinguished. 
> 
> Best regards,
> 
> --
> Mikael Rittri
> Carmenta AB
> Box 11354
> SE-404 28 Göteborg
> Visitors: Sankt Eriksgatan 5
> SWEDEN
> Tel: +46-31-775 57 37
> Mob: +46-703-60 34 07 
> mikael.rittri at carmenta.com
> www.carmenta.com 
> 
> -----Original Message-----
> From: metacrs-bounces at lists.osgeo.org [mailto:metacrs-bounces at lists.osgeo.org] On Behalf Of Christopher Schmidt
> Sent: den 16 december 2008 00:18
> To: metacrs at lists.osgeo.org
> Subject: [MetaCRS] failed epsg wkt (geotools)
> 
> SpatialReference.org now has a full EPSG database, pulled from the latest EPSG data files, with WKT produced by either GDAL or GeoTools for every code except for the following (along with their error messages from GeoTools):
> 
> 5818 failed:  Unknow axis direction: "Along receiver lines".
> 
> 63266406 failed:  Unsupported unit: 9116
> 63266407 failed:  Unsupported unit: 9117
> 63266408 failed:  Unsupported unit: 9115
> 63266409 failed:  Unsupported unit: 9118 63266410 failed:  Unsupported unit: 9119
> 63266412 failed:  Unsupported unit: 9120
> 63266414 failed:  Unsupported unit: 9116
> 63266415 failed:  Unsupported unit: 9117
> 63266416 failed:  Unsupported unit: 9115
> 63266417 failed:  Unsupported unit: 9118
> 63266418 failed:  Unsupported unit: 9119 63266420 failed:  Unsupported unit: 9120
> 
> 4882 failed:  Unknow axis direction: "Geocentre > equator/0?E".
> 4884 failed:  Unknow axis direction: "Geocentre > equator/0?E".
> 4886 failed:  Unknow axis direction: "Geocentre > equator/0?E".
> 4888 failed:  Unknow axis direction: "Geocentre > equator/0?E".
> 4890 failed:  Unknow axis direction: "Geocentre > equator/0?E".
> 4892 failed:  Unknow axis direction: "Geocentre > equator/0?E".
> 
> This is mostly just a 'for the record': At some point, I may look into this more to see if these codes should actually exist in some way. 5818 is almost definitely "no", since the scope says "Example only", but the
> 4882 -> 4892 set seems like a clear pattern that bears investigation. 
> 
> If anyone has suggestions as to ways to obtain sane WKT for these remaining codes, I'd love to hear suggestions.
> 
> Regards,
> --
> Christopher Schmidt
> MetaCarta
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-- 
Christopher Schmidt
MetaCarta