I have two sets of survey data for a stretch of river but the points from the newest survey weren't collected at the same locations as the first survey. I would like to subtract the newer data set from the older and create a surface from it. If the points had been collected at the same location I'd be able to use the "Minus" 3D analyst tool to do this, but that isn't the case.
I'm wondering if there is some way that I could create a grid that I could assign the z data from each survey to (so the x/y locations are coincident), and then use the minus function to find the data I'm looking for. I'm not overly concerned with matching the x/y locations of each point as close as possible, I'm just trying to get an idea of the elevation change over time. Any help with this would be greatly appreciated!