Distance Est

8/13/2019 Distance Est

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Methods of Determining

Distance

Once you have determine the direction,

you must determine the distance to the

target. Distance is the horizontal space

between a reference and the target or

between you and the target.

TB34AC # 2


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LASERS

are the preferred means of determining the OT distance.

When a laser is used, distance may be determined to the

nearest 10 meters.

FLASH-TO-BANG

When it is necessary to verify OT distance, the flash-to-

bang technique is helpful. Sound travels at a speed of

approximately 350 meters per second. Use the followingequation:

TB34AC # 3


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ESTIMATION

In the absence of a more accurate method of determining

distance to a target, the observer must estimate distance. The

degree of accuracy in this method depends on several

factors, such as terrain relief, time available, and theexperience of the observer.

Mental Estimation

mental estimate distance is made by use of a known unit ofmeasurement. Distance is estimated to the nearest 100

meters by determining the number of known units of measure

TB34AC # 4


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Estimation by EYE

Is a method of measuring the range byapplying to it a unit of measure 100 meters

long. This method is the same as that used in

measuring the length of the board with a ruler

The only difference is that the unit of measurement

measure mentally. Thorough familiarity with 100-

meter unit and its appearance on different types ofterrain and at different distances enable the

estimator to apply it with a fair degree off accuracy.


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Application of unit measurement beyond 500

meters is difficult. To estimate ranges over500 meters, select a halfway to the target,

apply the 100 meter unit up to the halfway

point, and double the result.

The average of a number of estimates by

different men is generally more accurate

than a single estimate. However , in

combat the soldier relies his own estimate.


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The observer should consider the following

effects of estimating distances:

Object appears nearer

When in bright light. When in clear air at higher altitude.

When the observer is looking down from a

height. When the observer is looking over a

depression,


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most of which is hidden.

When the observer is looking down a straight

feature, such as a road.

When the observer is looking over water,snow, or a

uniform surface such as a cultivated field.

When the background is in contrast with thecolor of

the object.


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When visibility is good, distances can be

estimated by using the appearance of tree

trunks, their branches, and foliage (usingthe naked eye) in comparison with map

data
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TB34AC # 12

DISTANCE TREE DESCRIPTION

1,000 meters Trunk and main branches are visible. Foliage

appears in cluster-like shape. Daylight may seen

through foliage.

2,000 meters Trunk is visible, main branches are

distinguishable, foliage appears as smooth

surface. Outline of foliage of separate trees is

visible.

3,000 meters Lower haft trunk is visible. Branches blend with

foliage . Foliage blends with adjoining trees.

4,000 meters Trunk and branches blend with foliage. Foliage

appears as a continues cluster. Motion cause by

the wind cannot detected.

5,000 meters and

beyond

Whole area covered by trees appear smooth and

dark.
http://localhost/var/www/apps/conversion/tmp/scratch_7/DESTANCE%20ESTIMATE.ppt%202.ppthttp://localhost/var/www/apps/conversion/tmp/scratch_7/DESTANCE%20ESTIMATE.ppt%202.ppt


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Estimating by Using Known

Dimensions

Distance can be estimated by using known

dimension of an object and the mil relation formula (W =Rxm). By applying the width, length or the height

appearing perpendicular to an observer as a lateral

distance (w) and measuring width in mils, the distance

can be determine by solving the formula for R inthousands, or R = W/m.

TB34AC # 13


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TB34AC # 14

FIXED WIDTH, LENGTH AND HEIGHT

OBJECT WIDTH (M) LENGTH HEIGHTDrum Metal 0.58 0.89Drum Plastic 0.55 0.90Window 0.75 0.75Door 0.90 2.12MiniCruiser 1.46 3.23 ------

Bicycle ------ 1.65 ------Motorcycle ------ 1.73 ------Elec. Post (Urban) ------ 10.0Elec. Post (Rural) ------ 6.0Rifle ------ 0.99 ------

Basket Ball Court 12.0 16.0 ------Basket Ball Ring ------ 3.04Fluorescent Lamp ------ 1.62 ------Hand Tractor ------ 2.0 ------Human Being ------ 1.62


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Width = 0.90m (Height of plastic drum)

Mils = 3 mils (Angular deviation seen from

bino)

Range = ?

R = W/m= .90/3

= .3 km

= .3 x 1000mtr

= 300mtr

Height of elec. Post = 6.0 mtr

Angular dev = 5 mils

Range = ?

R = w/m

= (6.0 / 5 ) x 1000mtr= 1200 mtrs


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Estimating From a Terrain Study

The observer should always use terrain-map

analysis to help him estimate distance. Athorough study of the terrain in comparison with

features or objects identifiable on the map can

enhance the estimation of distance. The

observer should make a mental terrain walk to

the target. He compares the features or objects

with those found on the map along the same

direction (OT line).TB34AC # 16


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TERRAIN SKETCH

Is a rough panoramic drawing of the area of observation prepared

by the observer constructed, it serves as a rapid means of

identifying direction and distance to reference point. Terrain sketch

also provide a rapid means of orienting relief personnel.

Items that included in a terrain sketch are

The skyline (horizon) Prominent features both natural and manmade.

Labels (reference points, known points, targets.)

TB34AC # 17


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TB34AC # 18


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Distance Est

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