S57 & Multipoint geometries

Topics: General Topics
Apr 27, 2011 at 3:07 PM

I am using the S57 OGR Provider to render S57 nautical charts.

If I use the FWTools, OGRINFO.EXE program to dump the chart layers, I can see that the SOUNDG layer is contains multipoint values, the first two values are the Latitude & Longitude, the third is the sounding (depth)

If I analyse the layers using SharpMap & the S57 OGR provider, the SOUNDG layer is a wkbMultiPoint25D geometry type and contains MULTIPOINT values, however these values only contain two values, the latitude & Longitude. Where do I get the sounding values from ?

Thanks in advance.

Coordinator
Apr 27, 2011 at 3:27 PM

SharpMap's OgrProvider calls FlattenTo2D() on ogr geometries.

If you need more than that from the geometry (like e.g. some m- or z-ordinate) you would have to extend the provider.

You may want to check with sharpmap develpoer pdiddy, who has takled a similar task (rendering nautical maps)

cheers FObermaier