[Proj] PROJ4: epsg:4135 broken?

[Daniel Morissette]

Frank,

I was going to submit this in the PROJ bugzilla, but it is currently
unavailable, so I decided to send to the list instead.

We have been trying to display GPS points (WGS84, EPSG:4326) over the
Hawaii TIGER data which is in the "Old Hawaiian" datum. The epsg file
that comes with PROJ contains code 4135 which is labelled as Old
Hawaiian, but the definition doesn't contain any datum information.

We tried to go from 4326 to 4135 but nothing happens. After a bit of
digging and research, we found some datum shift parameters for Old
Hawaiian, and I came up with the following definition which seems to
work for our data:

   +proj=longlat +ellps=clrk66 +towgs84=61,-285,-181,0,0,0,0

Is this the best we can do or is there a way we could use the "hawaii"
file that's in the proj directory? Should the epsg file be updated with
this fix?

Thanks

Daniel
-- 
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  Daniel Morissette               dmorissette at dmsolutions.ca
  DM Solutions Group              http://www.dmsolutions.ca/
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