In gunnery the unit of angular measurement is the mil. The mil is equal to 1/6400 of a circle (NATO; 1/6000 - ex-USSR). Mils facilitate easy and rapid conversion from angular units to linear, and vice versa, since the arc length corresponding to one mil equals one thousandth of the radius (distance to the target) at all distances. For example, at a distance of 500 m one mil equals 0.5 m, at 1 km - 1 m, 1.5 km - 1.5 m, etc. Knowing the size of the target and its visual angle, it is possible to determine the range to the target, or knowing the range and size, to determine the visual angle of the target, etc.
where: D - range to the target in meters, A - scope size of the target in mils, H - height (width) of the target in meters.
In ex-USSR angles in mils are usually written in two groups: first group - hundreds of mils, the second - tens and ones. E.g., 1 mil is 0-01, 100 mils is 1-00, etc.
ExampleEnemy tank, width 3.5 m, visible at angle about 0-04. Determine the distance.
Solution:
H * 1000 3.5 * 1000
D = -------- = ---------- = 875 m.
A 4
Reticles subtensionsT-62Binocular
Commander's vision device TKN-3
Telescope sight TSh2B-41
Night sight TPN-1-41-11
Collimator sight K10-T (DShK)
M60Binocular
Periscope nonballistic reticle M32
Telescope ballistic reticle M105D
Machinegun sight M28C (M85)
Range estimation tables
Mils 10 9 8 7 6 5 4 3 2 1
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T-62, T-55, BRDM-2, GAZ-66, M113A1//////////////////////////////////////////////////////////
Height 2,4 m 250 250 300 350 400 500 600 800 1200 2400
BMP-1, BTR-60///////////////////////////////////////////////////////////////////////////////
Height 2,2 m 200 250 300 300 350 450 550 750 1100 2200
M60A1///////////////////////////////////////////////////////////////////////////////////////
Height 3,2 m 300 350 400 450 550 650 800 1050 1600 3200
Chieftain Mk.5//////////////////////////////////////////////////////////////////////////////
Height 2,6 m 250 300 350 350 450 500 650 850 1300 2600
Olifant Mk IA///////////////////////////////////////////////////////////////////////////////
Height 3,6 m 350 400 450 500 600 700 900 1200 1800 3600
Ratel///////////////////////////////////////////////////////////////////////////////////////
Height 2,9 m 300 300 350 400 500 600 750 950 1450 2900
Man-sized target////////////////////////////////////////////////////////////////////////////
Height 1,7 m 150 200 200 250 300 350 450 550 850 1700
Single storey house/////////////////////////////////////////////////////////////////////////
Height 4,5 m 450 500 550 650 750 900 1150 1500 2250 4500
Telegraph post//////////////////////////////////////////////////////////////////////////////
Height 6 m 600 650 750 850 1000 1200 1500 2000 3000 6000
Mils 10 9 8 7 6 5 4 3 2 1
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T-62, T-55//////////////////////////////////////////////////////////////////////////////////
Length 6,6 m 650 750 850 950 1100 1300 1650 2200 3300 6600
Width 3,3 m 350 350 400 450 550 650 850 1100 1650 3300
BMP-1///////////////////////////////////////////////////////////////////////////////////////
Length 6,7 m 650 750 850 950 1100 1350 1700 2250 3350 6700
Width 2,9 m 300 300 350 400 500 600 750 950 1450 2900
BTR-60//////////////////////////////////////////////////////////////////////////////////////
Length 7,6 m 750 850 950 1100 1250 1500 1900 2550 3800 7600
Width 2,8 m 300 300 350 400 450 550 700 950 1400 2800
BRDM-2, GAZ-66//////////////////////////////////////////////////////////////////////////////
Length 5,8 m 600 650 750 850 950 1150 1450 1950 2900 5800
Width 2,4 m 250 250 300 350 400 500 600 800 1200 2400
M60A1, Chieftain Mk.5, Olifant Mk IA////////////////////////////////////////////////////////
Length 7,5 m 750 850 950 1050 1250 1500 1900 2500 3750 7500
Width 3,5 m 350 400 450 500 600 700 900 1150 1750 3500
M113A1//////////////////////////////////////////////////////////////////////////////////////
Length 4,9 m 500 550 600 700 800 1000 1250 1650 2450 4900
Width 2,7 m 250 300 350 400 450 550 700 900 1350 2700
Ratel///////////////////////////////////////////////////////////////////////////////////////
Length 7,2 m 700 800 900 1050 1200 1450 1800 2400 3600 7200
Width 2,5 m 250 300 300 350 400 500 650 850 1250 2500