IMU accelerometer displacement measuring 10 meters or more

Does anyone here have experience with displacement measuring in the tens of meters range using an Arduino managed IMU? My application would not require high accuracy ( could be off a meter in 10) but would have to ignore (filter, damp out) the natural oscillations of the platform at either end of the displacement and as it moved.

This idea may be crazy. I can't tell if it is.

I've done something like this with gps. The accuracy i'm getting seems better than could be expected given the error associated with the gps, but since I'm not interests in actual position, only relative, and it appears that the positional error is persistent, I can get a good displacement measurement so long as I don't care about the precision of the actual position.

Maybe this is nuts too. Any observations on either of the above?