I think I remebering seeing a device like a transit that sat on a post on your show. You set a reference point and then moved the post around the yard and it told you how much of height change from reference you have. It was a one person operated device. It was all digital and I think you could map your whole yard and put it in the computer or something. Well I now have a use for it but can not remember who made it or what is called. Can anyone help me thanks.