NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Milli-radian
From: Doug Royer
Date: 2003 Mar 12, 10:41 -0800
From: Doug Royer
Date: 2003 Mar 12, 10:41 -0800
Thanks to you guys an area of puzzelment has been cleared up for me.I often wondered how a unit of linear measurement 0.001 was called a mil or a thousanth.Milli-radian.It makes sense to me now.A unit of angular measure over a short distance (relative) would appear as a straight line.Much like a rhum line on a Mercator projection. I have 2 mil or lensatic compasses.One is the Cammenga lensatic compass and the other is an older Soviet Bussol compass.The Cammenga is handheld and the Bussol is a bit larger and can be mounted on a tripod.The Bussol may be more accurate due to the greater number of mil markings on the card face.The Cammenga is mil marked for every 5 mils and the Bussol has markings at what appear every 2 mils.It is also interesting in the post yesterday to discover that Russian and US mil markings differ and I will dig deeper into this area.I don't know the differance between the Cammenga and the US-M2 compass but will find out today.The Bussol also has a contraption for what appears to find elevation.It was most likely used to lay artillary positions.I can't find any documentation on this compass but you have given me some insight on figureing out how it works. Ever since joining this group I haven't had a chance to read any books as I am reading through years of your archives.What a store of knowlage and information! I've never thought of or considered doing Lunar distance observations but now that I have some time it sounds like a real challange to attempt them. Back to the Cammenga mil-compass.The bezel has a ratchet and is 120 clicks per rev.Each click is = 53.333 mils or 3*.Each 1* is = 17.778 mils. 1 mil subtends 39.37 in. @ 1,000 yds. 1 min. of angle subtends 11.83 in. @ 1,000yds. 1 sec. of arc subtends 0.2 in. @ 1,000 yds. On to the UTM projection.UTM's have Northing and Easting coordinates.Each section of the globe has differant East + West and North + South letters designating the desired area to use as a prefix to the Northing and Easting coordinates.Grids are marked as 1,000 meter boxes.Resolution is as follows. 6 digit Northing and Easting coordinates = 100 meter accuracy 8 digit coordinates = 10 meter accuracy 10 digit coordinates = 1 meter accuracy Gentleman,I have to run and do something now so I'll finish later.