If you have any high precision XYZ data which could be licensed under a free license please donate it to the project.
The RMS error must be equal or smaller than 3 meters. The values should be comma separated (.csv) or in the case of a Raster in the Geo Tiled Image File Format (.tif).
The data should be supplied in the original reference system. Coordinate Transformations could be very tricky, but height value transformation is even much more complicated because it is not yet supported by free software packages. Therefore the dataset should be provided in the original reference system and the user could decide how to transform the data.
Free GIS software like Quantum GIS could easily import the data (delimited textfileplugin), visualise and reproject it. Reprojections could be done with different free software packages like FWTools, GRASS and PostGIS. All the above mentioned software is based on the Proj4 library, a free Projection library. Please be aware that the result of a transformation could differ from other GIS software which is not based on Proj4, even with the same ESPGs!
High Resolution Stereo Camera, Flight in 2002, Corrected 2005 by the University of Rostock, No Parameters for the RMS error are available but the precision should be about < 1 m (horizontal & vertical). Only coordinates of the buildings, not a sufficent model.
Kataster-, Vermessungs- und
Liegenschaftsamt Rostock (Emergency planning, surveying and land registration department, Rostock)