NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Learn the stars, by phone
From: Gary LaPook
Date: 2009 May 14, 23:06 +0200
From: Gary LaPook
Date: 2009 May 14, 23:06 +0200
Having been a tank commander for many years I remember dismounting many times and taking a long walk out in front of the tank with my lensatic compass to take an azimuth, brings back memories. (http://www.map-reading.com/cmpuse.php) I spent even more years in the field artillery using an M2 Aiming circle to "lay" the the four, eight inch howitzers in my battery (establish a common direction of fire for all the guns in the battery) having to set it up at least 75 meters from the nearest artillery piece or large metal object (150 meters from power lines) and I had to "ground" my rifle and web belt (take it all off and lay it on the ground) at least 10 meters from the aiming circle so as not to disturb the compass needle in the aiming circle. (http://www.fas.org/man/dod-101/sys/land/docs/GDO2FA/sld074.htm) While I was setting up the aiming circle my gun guides would be using their M2 compasses (actually Brunton Pocket Transits marked in mils instead of degrees http://www.brunton.com/product.php?id=144) to guide the guns into position before I could lay them. It is amazing how accurate and sensitive these instrument are to any ferrous metal and these precautions were necessary for accurately determining direction of fire. gl James N Wilson wrote: > George: > > Your discussion of problems with compasses reminded me of an ancient > experience--putting a compass in a tank. I headed a team to advise the > army, and they were looking for a more modern way than the existing one: > the tank commander stopped the tank, got out and walked fifty feet away > and read his hand compass. They had been sold on a scheme which had an > aircraft fluxgate compass on a fender, but it was awful. Deviation of up > to 300 degrees! I couldn't believe it. The only way it worked was with > the tank stopped on level ground pointing north. Not very utile. > > A general asked me could GPS be used to get a heading. I asked our JPL > navigators about that, and they came up with two schemes that could do > the job. Of course, that's common now, and a lot more. > > Jim Wilson > ____________________________________________________________ > Digital Photography - Click Now. > > > > > --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---