If you have worked in GIS then you have probably fused raster elevation data. So, chances are that you have also torn your hair out if these data came from different sources and had accuracy biases or projection difference. Trying to get a seamless merging of two separate elevation sets is never as easy as it initially sounds. The problems can be as complex as the misalignment of the origin point in reprojection or a reference to pixel center vs. pixel corner. Or, they can be as simple as a vertical offset or a planar tilt.
Intermap® has worked very hard to simplify the data fusion process. Over the course of a couple years we have been developing a data fusion tool and a universal projector tool. With these tools now complete, we are able to reproject to hundreds of vertical and horizontal datums with validated precision. And, with our automated fusion tool the user loads the data and species the reference data then the tool does the rest. Overlapping areas area removed, vertical bias applied, data is tilted to minimize all edges around the fusion boundary and the remaining seams are blended to complete the process.