Peter that's an awesome idea but I am creating a projectile that flies through the air and has that and a 2 axis gyro (X and Y axis sensing) that corrects its trajectory and adjusts 2 sets of flaps on the back to go a spafic distance I can model the exit speed very well (mab just use that inatility to smooth out the huge jump in readings)
... and now the true requirements start to come out!
Do you know how high the landing point is relative to the launch point?
Do you actually know the launch speed and direction?
Am I correctly understanding that the projectile is NOT ballistic? I don't think a two-axis gyro will give you enough information to know where it is, since you don't know the orientation and hence direction of acceleration. If it flies consistently and generally stays in a predictable orientation you might be able to fudge that.