[postgis-users] circular arcs in postgis?

[Hubert Fröhlich]

Hi list,

I am using postgis for storing and processing land register data.

However, unfortunately, in our data model, the real estate plots are 
some kind of "multipolygon", however not in the "OGC Simple Feature for 
  SQL" sense - which restricts borders to straight lines

( in GML:
<gml:LineStringSegment>
<gml:pos> 4547584.06 5317944.32 </gml:pos>
<gml:pos> 4547590.66 5317944.07 </gml:pos>
</gml:LineStringSegment>
)

, but also with cicrular arcs allowed as borders:

e.g. in GML

<gml:Arc interpolation="circularArc3Points">
<gml:pos> 4547582.29 5317942.87 </gml:pos>
<gml:pos> 4547582.92 5317943.89 </gml:pos>
<gml:pos> 4547584.06 5317944.32 </gml:pos>
</gml:Arc>

I know this is a rather complicated issue - and I can't avoid it because 
the "data model" is from the good old days of analog mapping, measuring 
and calculating ,
I know that things (calculations) might turn really VERY complicated, 
but - is there a chance to extend Postgis data handling so such data 
types, maybe only in a rudimentary way?

Greetings,

Hubert
-- 
-------------------------------------------------------------------------------
Dr.-Ing. Hubert Fröhlich			
Bezirksfinanzdirektion München 			
Alexandrastr. 3, D-80538 München, GERMANY
Tel. :+49 (0)89 / 2190 - 2980
Fax  :+49 (0)89 / 2190 - 2997
hubert dot froehlich at bvv dot bayern dot de