Terrain Modelling Inputs

Hi Everyone

I could use some help with a terrain model I am putting together in Descartes for export to Microstation CE and ultimately LumenRT.  I am not a civil drafter, and could use some advice in this regard.

I have created an STM in Decartes and exported it as a TM.  In Microstation I have added the draped image as a material. The TM is in point data in xyz format from a survey.  The area of the survey is a little too small for what I need, so I have some Google Earth meshes which I created in Microstation (AECOSIM). These are adjacent to the surveyed area and I have referenced them into the Microstation file with the TM.  They don't match exactly - can anyone suggest how to go about cleaning up the interface between the 2?  I have tried manipulating the mesh. no good. Is there any way of doing it in the STM in Descartes?

As you can see from the screen shot, the orange is the TM and the green bit is the Google Earth mesh. The intersection at the edge is far from perfect.  Any advice gratefully received.

-W