Learn how to use the lensatic compass used by the US Military. PRECISION COMPASS. * LENSATIC *. PROVEN • RUGGED ACCURATE. CAMMENGA. FAX ( ANILINE AVE. HOLLAND, MICHIGAN I get lots of questions via email from people wanting to know how to use a lensatic compass, and I think I’ve covered that pretty well in a series of two posts.
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I guess the military needs the extra accuracy now and then say, for example, to precisely place artillery fire. When hiking, use a map to help you navigate unfamiliar terrain. A plot of the traverse can then be ldnsatic, and the enclosed area calculated.
It’s important to hold your compass stable, squarely in front of you, and level. A few terms may be defined for the benefit of those not accustomed to them. Have no fear, the science here is sound a proven. That line should intersect reasonable close to where the other lines crossed. The compass points to magnetic north, which is a very doubful concept in most places. It has its advantages and disadvantages over the orienteering compass.
The lensatic “prismatic” compass is only mentioned briefly. Hold a compass level and steady to prevent the needle engibeer touching the sides of the globe or the dial face.
Lensatic Compass Guide
Keep your head still and then read the azimuth through the lens bracket. Most mid-latitude inhabited areas cmpass smaller and more regularly varying declinations. What I haven’t covered in much detail is some of the nuances of lensatic compasses, such as the tips and tricks to getting the most out of them in the field. Compasses are made from brass or plastic, which are nonmagnetic. The perpendicular distance from the road to Antelope Hill is b sin A or a sin B, which gives ‘.
The angles are measured from N or S. Line up the sighting groove in the bracket with the wire and an object in the distance. FM does not mention the use of the short line, but it can probably be used to speed up the setting of an azimuth by saving 15 clicks.
Iron on or near one’s person is a fertile source of deviation. A web search revealed a lot about compasses and geomagnetism, but no good explanation of the lensatic compass.
You now have your target’s bearing. These storms are associated with solar flares, so they recur at day intervals, which is the rotational period of the sun. You can use this feature to set your compass in the dark. The directions of true and magnetic north are indicated on the sketch.
Turn your entire body as a unit until your predetermined azimuth falls under the fixed black index line. Turn compxss compass in a horizontal manner until the azimuth is directly beneath the black index line on the face.
Lensatic Compass Guide
When you make a closed traverse, there is a check on the bearings and the pacing the traverse should close. The sun sends ionizing ultraviolet radiation reaching the earth in about 8 minutes after it is emitted, and streams of particles, mainly protons, that take longer to reach the earth. The declination changes slowly with time less than 10′ annuallyso an up-to-date declination map coompass necessary.
Then, you enineer your protractor on the map with its center point at your current position, mahual sure the north-south lines on the protractor line up with the north-south lines on the map. These come from sunspots in the normal sun, but in increased amounts from disturbances called solar flares. Now, hold the compass level and squarely in front of you. How to Calculate Azimuth.
My page, fully illustrated book is yours for the asking. Hold your compass in the two-hand hold, steady and level in front of you. The Law of Sines gives us the unknown sides: A web search for “magnetic declination” will find world maps that are quite lrnsatic, showing places where the compass is useless. The back azimuth compas nothing more than the opposite direction of the reading you’re taking.
They have no significance for compass measurements, but are of intrinsic interest, and this seems the best place to discuss them. Some compasses are like this, but they could not be used in the same way to measure a bearing.
Imagine that you want to hold it as if it were firmly mounted in that position. After reading those two articles anyone should be able to go out and perform basic land navigation with a map and lensatic compass. In nautical terminology, declination is called variationwhile the effects of the ship’s iron is called deviation. This “crosshair” is actually a sturdy metallic wire.
Most people are aware that lensatic compasses are fitted with small amounts of tritium around the dial. A bearing is the angular position of a line in a horizontal plane.
Want a free ebook on Land Navigation? A ship is swungjanual pointed to different azimuths, to determine the effect of induced magnetism. It can also be used to orient a map. Do not move your head, but raise and lower your eyes when taking the azimuth using an engineer compass. Use the engineer compass to find the direction by lining up the compass with an object.