Hi Guys I am new engineering and would appreciate any advice or ideas on this project. I need to measure the height above sea level of a small vehicle that I am building.. My first idea was GPS, but the vehicle is going travel under a thick steel structure, so it will not work. I thought about a pitot tube but there are many random gusts of wind, so the readings may be compromised. I need an accuracy of about 10mm. Any input will be much appreciated. Thanks!