Or you could try an ultrasonic Doppler sensor (car back-up device). The int= erface ice water will cause a reflection, so you can deduct ice thickness. =A0 Good luck, Jean-Paul AC9GH "Democracy is two wolves and a lamb deciding what to have for dinner.=20 Liberty is a well-armed lamb." - Benjamin Franklin - On Wednesday, November 6, 2013 10:58 PM, BOB wrote: =20 After much reading I think a robot with a drill attachment. as you apply down pressure the robot front lifts. Start the drill. When=20 the robot drops the drill is through the ice.=A0 Take a measurement and=20 move on. With a small GPS unit and a radio link you could map out a body of water=20 or ice. Something to think about for when I have too much time on my hands. Bob On 11/6/2013 7:29 PM, Robert Rolf wrote: > Contactless Ice thickness meter > http://uwbs.ru/en/products/izmeritel-tolschiny-lda-picor-ice/ > > http://www.beckerarena.com/UserFiles/File/Library/Ice%20Tec%208%20Manual.= pdf > > and plenty more with google search > > On Wed, Nov 6, 2013 at 6:26 PM, Robert Rolf wro= te: >> Ultrasound. Commercial thickness gauges for steel cover a few inches. >> Don't know about ice. >> Some experts can tell from sledge hammer thump on top. >> >> >> On Wed, Nov 6, 2013 at 6:06 PM, BOB wrote: >>> I have a friend who is a die hard ice fisherman.=A0 He was wondering if >>> there is a way to measure the thickness of ice on a lake with out >>> drilling a hole in it. >>> >>> Anyone know of some type of sensor that would do this? >>> >>> Bob >>> -- >>> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive >>> View/change your membership options at >>> http://mailman.mit.edu/mailman/listinfo/piclist >>> --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .