How to determine the distance using a ruler - wind in a field. Methods for determining the distance to a target using an optical sight Measuring the range to an object
Section 4. Field measurements and target designation
§ 1.4.1. Angle measures and thousandth formula
Degree measure. The basic unit is degree (1/90 of a right angle); 1° = 60"; 1"=60".
Radian measure. The basic unit of radians is the central angle subtended by an arc equal to the radius. 1 radian is equal to approximately 57°, or approximately 10 major divisions of the protractor (see below).
Marine measure. The basic unit is the rhumb, equal to 1/32 of a circle (10°1/4).
Hourly measure. The basic unit is the arc hour (1/6 of a right angle, 15°); denoted by the letter h, in this case: 1 h = 60 m, 1 m = 60 s ( m– minutes, s- seconds).
Artillery measure. From a geometry course we know that the circumference of a circle is 2πR, or 6.28R (R is the radius of the circle). If the circle is divided into 6000 equal parts, then each such part will be equal to approximately one thousandth of the circumference (6.28R/6000 = R/955 ≈ R/1000). One such part of the circumference is called thousandth (or dividing the protractor ) and is the basic unit of artillery measure. The thousandth is widely used in artillery measurements because it allows easy transition from angular units to linear units and back: the length of the arc corresponding to the division of the protractor at all distances is equal to one thousandth of the length of the radius equal to the firing range (Fig. 4.1).
The formula showing the relationship between the range to the target, the height (length) of the target and its angular magnitude is called thousandth formula and is used not only in artillery, but also in military topography:
Where D- distance to the object, m; IN - linear size of the object (length, height or width), m; U - the angular magnitude of the object in thousandths. Memorizing the thousandth formula is facilitated by such figurative expressions as: “ The wind blew, a thousand fell ", or: " A milestone 1 m high, 1 km distant from the observer, is visible at an angle of 1 thousandth ».
It should be taken into account that the thousandths formula is applicable at angles that are not too large - the conditional limit of applicability of the formula is an angle of 300 thousandths (18?).
Angles expressed in thousandths are written with a hyphen and read separately: first hundreds, and then tens and units; if there are no hundreds or tens, zero is written and read. For example: 1705 thousandths are written " 17-05 ", read - " seventeen zero five "; 130 thousandths are written " 1-30 ", read - " one thirty "; 100 thousandths are written " 1-00 ", read - " one zero "; one thousandth is written " 0-01 ", reads - " zero zero one ».
Protractor divisions written before the hyphen are sometimes called major protractor divisions, and those written after the hyphen are called small ones; One major division of the protractor is equal to 100 small divisions.
The divisions of the protractor into degree measures and back can be converted using the following relationships:
1-00 = 6°; 0-01 = 3.6" = 216"; 0° = 0-00; 10" ≈ 0-03; 1° ≈ 0-17; 360° = 60-00.
A unit of measurement for angles similar to the thousandth also exists in armed forces NATO countries. It's called there mil(short for milliradian), but defined as 1/6400 of a circle. In the non-NATO army of Sweden, the most accepted precise definition at 1/6300 of a circle. However, the 6000 divisor adopted in Soviet, Russian and Finnish armies, is better suited for mental counting, since it is divisible without a remainder by 2, 3, 4, 5, 6, 8, 10, 12, 15, 20, 30, 40, 50, 60, 100, 150, 200, 250, 300, 400, 500, etc. up to 3000, which allows you to quickly convert into thousandths of angles obtained by rough measurements on the ground using improvised means.
§ 1.4.2. Measuring angles, distances (ranges), determining the height of objects
Rice. 4.2 Angular values between the fingers of a hand extended 60 cm from the eye
Angles can be measured in thousandths different ways: eye-wise, by using clock dial, compass, artillery compass, binoculars, sniper scope, ruler, etc.
Visual angle determination consists in comparing the measured angle with a known one. Angles of a certain size can be obtained in the following ways. A right angle is obtained between the direction of the arms, one of which is extended along the shoulders, and the other straight in front of you. From the angle formed in this way, you can set aside some part of it, keeping in mind that 1/2 part corresponds to the angle 7-50 (45°), 1/3 to the angle 5-00 (30°), etc. Angle 2-50 (15°) is obtained by sighting through the large and index fingers, placed at an angle of 90° and 60 cm away from the eye, and the angle 1-00 (6°) corresponds to the viewing angle of three closed fingers: index, middle and ring (Fig. 4.2).
Determining the angle using a watch dial. The watch is held horizontally in front of you and rotated so that the stroke corresponding to 12 o'clock on the dial aligns with the direction of the left side of the corner. Without changing the position of the clock, notice the intersection of the direction right side angle with the dial and count the number of minutes. This will be the value of the angle in large divisions of the protractor. For example, the countdown of 25 minutes corresponds to 25-00.
Determining an angle with a compass. The sighting device of the compass is first aligned with the initial stroke of the dial, and then sighted in the direction of the left side of the angle being measured and, without changing the position of the compass, a reading along the dial is taken against the direction of the right side of the angle. This will be the value of the measured angle or its addition to 360° (60-00), if the signatures on the dial go counterclockwise.
Rice. 4.3 Compass
The magnitude of the angle can be determined more accurately with a compass by measuring the azimuths of the directions of the sides of the angle. The difference in azimuths of the right and left sides of the angle will correspond to the size of the angle. If the difference turns out to be negative, then you need to add 360° (60-00). The average error in determining the angle using this method is 3-4°.
Determining the angle using an artillery compass PAB-2A (a compass is a device for topographical reference and control of artillery fire, which is a connection of a compass with a goniometer circle and an optical device, Fig. 4.3).
To measure the horizontal angle, the compass is installed above a point in the terrain, the level bubble is brought to the middle and the pipe is sequentially pointed first at the right, then at the left object, precisely aligning the vertical thread of the reticle crosshair with the point of the observed object.
At each pointing, a count is taken along the compass ring and drum. Then the second measurement is performed, for which the compass is turned to an arbitrary angle and the steps are repeated. In both methods, the angle value is obtained as the difference in readings: the reading on the right object minus the reading on the left object. The average value is taken as the final result.
When measuring angles with a compass, each count is composed of the count of large divisions of the compass ring according to the indicator marked with the letter B, and the small divisions of the compass drum, marked with the same letter. Example of readings in Fig. 4.4 for the compass ring - 7-00, for the compass drum - 0-12; full countdown - 7-12.
Rice. 4.4 Compass reading device used to measure horizontal angles:
1 - bead ring;
2 - compass drum
Using a ruler . If the ruler is held at a distance of 50 cm from the eyes, then a division of 1 mm will correspond to 0-02. When the ruler is removed from the eyes by 60 cm, 1 mm corresponds to 6", and 1 cm corresponds to 1°. To measure an angle in thousandths, hold the ruler in front of you at a distance of 50 cm from the eyes and count the number of millimeters between objects indicating the directions of the sides of the angle. The resulting number multiply by 0-02 and get the angle in thousandths (Fig. 4.5).To measure the angle in degrees, the procedure is the same, only the ruler must be held at a distance of 60 cm from the eyes.
Rice. 4.5 Measuring an angle with a ruler 50 cm from the observer's eye
The accuracy of measuring angles using a ruler depends on the ability to place the ruler exactly 50 or 60 cm from the eyes. In this regard, we can recommend the following: a cord of such length is tied to an artillery compass so that the ruler of the compass, hung on the neck and placed forward at the level of the observer’s eye, is exactly 50 cm away from him.
Example: knowing that the average distance between the communication line posts shown in Fig. 1.4.5 is 55 m, we calculate the distance to them using the thousandth formula: D = 55 x 1000 / 68 = 809 m (linear dimensions of some objects are given in Table 4.1) .
Table 4.1
Measuring an angle with binoculars . The extreme line of the scale in the field of view of the binoculars is combined with an object located in the direction of one of the sides of the corner, and, without changing the position of the binoculars, count the number of divisions to the object located in the direction of the other side of the corner (Fig. 4.6). The resulting number is multiplied by the value of the scale divisions (usually 0-05). If the binocular scale does not completely cover the angle, then it is measured in parts. The average error in measuring angles with binoculars is 0-10.
Example (Fig.4.6): angular value American tank"Abrams", determined by the binocular scale, was 0-38, taking into account that the width of the tank is 3.7 m, the distance to it, calculated using the thousandth formula, D = 3.7 X 1000 / 38 ≈ 97 m.
Measuring an angle with a PSO-1 sniper scope . Marked on the sight reticle (Fig. 4.7): lateral correction scale (1); main (upper) square for aiming when shooting up to 1000 m (2); additional squares (below the lateral correction scale along the vertical line) for aiming when shooting at 1100, 1200 and 1300 m (3); rangefinder scale in the form of solid horizontal and curved dotted lines (4).
The lateral correction scale is marked below (to the left and right of the square) with the number 10, which corresponds to ten thousandths (0-10). The distance between two vertical lines of the scale corresponds to one thousandth (0-01). The height of the square and the long stroke of the lateral correction scale corresponds to two thousandths (0-02). The rangefinder scale is designed for a target height of 1.7 m (average human height). This target height value is indicated below the horizontal line. Above the upper dotted line there is a scale with divisions, the distance between which corresponds to a distance to the target of 100 m. Scale numbers 2, 4, 6, 8, 10 correspond to distances of 200, 400, 600, 800, 1000 m. Determine the range to the target using The sight can be adjusted using the rangefinder scale (Fig. 4.8), as well as the lateral correction scale (see the algorithm for measuring angles with binoculars).
Knowing the distance to an object in meters and its angular magnitude in thousandths, you can calculate its height using the formula H = L x Y / 1000, obtained from the thousandths formula. Example: the distance to the tower is 100 m, and its angular value from the base to the top is 2-20, respectively, the height of the tower B = 100 x 220 / 1000 = 22 m.
Visual determination of distances is carried out according to the signs of visibility (degree of distinguishability) of individual objects and targets (Table 4.2).
| Signs of visibility | Range |
| Rural houses are visible | 5 km |
| Windows differ in houses | 4 km |
| Individual trees and pipes on the roofs are visible | 3 km |
| Individual people are visible; tanks from cars (armored personnel carriers, infantry fighting vehicles) are difficult to distinguish | 2 km |
| A tank can be distinguished from a vehicle (armored personnel carrier, infantry fighting vehicle); communication lines are visible | 1.5 km |
| The gun barrel is visible; different tree trunks in the forest | 1 km |
| Movements of the arms and legs of a walking (running) person are noticeable | 0.7 km |
| The tank's commander's cupola and muzzle brake are visible, and the movement of the tracks is noticeable. | 0.5 km |
Table 4.2
Distance (range) can be determined by eye by comparison with another, previously known distance (for example, with the distance to a landmark) or segments of 100, 200, 500 m.
The accuracy of visual determination of distances is significantly influenced by observation conditions:
- brightly lit objects appear closer to dimly lit ones;
- on cloudy days, rain, twilight, fog, all observed objects seem further away than in sunny days;
- large objects seem closer than small ones located at the same distance;
- brightly colored objects (white, yellow, orange, red) seem closer to dark ones (black, brown, blue);
- in the mountains, as well as when observed through water, objects seem closer than in reality;
- when observing while lying down, objects seem closer than when observing while standing;
- when viewed from bottom up, objects appear closer, and when viewed from top to bottom, objects appear further away;
- When observed at night, luminous objects appear closer, and darkened objects appear farther than they really are.
An eye-determined distance can be clarified by the following methods:
- the distance is mentally divided into several equal segments (parts), then the value of one segment is determined as accurately as possible and the desired value is obtained by multiplication;
- The distance is assessed by several observers, and the average value is taken as the final result.
With sufficient experience, a distance of up to 1 km can be determined by eye with an average error of the order of 10-20% of the range. When determining large distances, the error can reach 30-50%.
Determining range by sound audibility used in poor visibility conditions, mainly at night. Approximate hearing ranges of individual sounds under normal hearing and favorable weather conditions are given in Table 4.3.
| Object and character of sound | Hearing range |
| Low talking, coughing, low commands, loading weapons, etc. | 0.1-0.2 km |
| Driving stakes into the ground manually (evenly repeated strikes) | 0.3 km |
| Chopping or sawing wood (the sound of an ax, the squeal of a saw) | 0.4 km |
| Movement of a unit on foot (even dull noise of footsteps) | 0.3-0.6 km |
| Falling of felled trees (crackling of branches, dull impact on the ground) | 0.8 km |
| Car movement (even dull engine noise) | 0.5-1.0 km |
| Loud scream, fragments of trenches (shovel hitting stones) | 1.0 km |
| Car horns, single machine gun shots | 2-3 km |
| Firing in bursts, movement of tanks (clanging tracks, sharp rumble of engines) | 3-4 km |
| Gun firing | 10-15 km |
Table 4.3
The accuracy of determining distances based on the audibility of sounds is low. It depends on the experience of the observer, the acuity and training of his hearing and the ability to take into account the direction and strength of the wind, the temperature and humidity of the air, the nature of the relief, the presence of shielding surfaces that reflect sound, and other factors affecting the propagation of sound waves.
Determining range by sound and flash (shot, explosion) . Determine the time from the moment of the flash to the moment the sound is perceived and calculate the range using the formula:
D = 330 t ,
Where D - distance to the flash point, m; t - time from the moment of flash to the moment of perception of sound, s. Wherein average speed sound propagation is assumed to be 330 m/s ( Example: the sound was heard 10 s after the flash, respectively, the distance to the explosion site is 3300 m).
Determining range using an AK front sight . Determining the range to the target, having developed the appropriate skill, can be done using the front sight and the slot of the AK sight. It is necessary to take into account that the front sight completely covers target No. 6 ( target width 50 cm) at a distance of 100 m; the target fits in half the width of the front sight at a distance of 200 m; the target fits in a quarter of the width of the front sight at a distance of 300 m (Fig. 4.9).
Rice. 4.9 Determining range using an AK front sight
Determining range by measuring steps . When measuring distances, steps are counted in pairs. A pair of steps can be taken as an average of 1.5 m. For more accurate calculations, the length of a pair of steps is determined by measuring in steps a line of at least 200 m, the length of which is known from more accurate measurements. With an equal, well-calibrated step, the measurement error does not exceed 5% of the distance traveled.
Determining the width of a river (ravine and other obstacles) by constructing an isosceles right triangle (Fig. 4.10).
Determining the width of a river by constructing an isosceles right triangle
Select a point near the river (obstacle) A so that some landmark is visible on its opposite side IN and, in addition, along the river it would be possible to measure a line. At the point A restore perpendicular AC to the line AB and in this direction measure the distance (with a cord, steps, etc.) to the point WITH , in which the angle DIA will be equal to 45°. In this case the distance AC will correspond to the width of the obstacle AB . Full stop WITH found by approximation, measuring the angle several times DIA in any available way (compass, watch or eye).
Determining the height of an object by its shadow . A pole (pole, shovel, etc.) is installed at the object in a vertical position, the height of which is known. Then measure the length of the shadow from the pole and from the object. The height of an object is calculated using the formula
h = d 1 h 1 / d,
Where h – object height, m; d 1 – height of the shadow from the pole, m; h 1 – pole height, m; d – length of the shadow from the object, m. Example: the length of the shadow from a tree is 42 m, and from a pole 2 m high - 3 m, respectively, the height of the tree is h = 42 · 2 / 3 = 28 m.
§ 1.4.3. Determining the steepness of slopes
Horizontal sighting and measuring in steps . Located at the bottom of the slope at the point A(Fig.4.11- A), set a ruler horizontally at eye level, sight along it and notice a point on the slope IN. Then measure the distance in pairs of steps AB and determine the steepness of the slope using the formula:
α = 60/n,
Where α – slope steepness, degrees; n– number of pairs of steps. This method is applicable for slope slopes up to 20-25°; determination accuracy 2-3°.
Comparing the height of the slope with its location . Stand on the side of the ramp and, holding horizontally in front of you at eye level, the edge of the folder and vertically a pencil, as shown in Fig. 4.11- b, determined by eye or by measurement, a number indicating how many times the extended part of the pencil MN shorter than the edge of a folder OM. Then 60 is divided by the resulting number and as a result the slope of the slope is determined in degrees.
For greater accuracy in determining the relationship between the height of the slope and its location, it is recommended to measure the length of the edge of the folder, and use a ruler with divisions instead of a pencil. The method is applicable when the slope slope is no more than 25-30°; the average error in determining the steepness of the slope is 3-4°.
Determination of slope steepness:
a – horizontal sighting and measuring in steps;
b – comparing the heights of the slope with the foundation
Example: the height of the extended part of the pencil is 10 cm, the length of the edge of the folder is 30 cm; the ratio of the location and height of the slope is 3 (30:10); the slope will be 20° (60:3).
Using a plumb line and an officer's ruler . Prepare a plumb line (thread with a small weight) and apply it to officer line, holding the thread with your finger at the center of the protractor. The ruler is installed at eye level so that its edge is directed along the line of the slope. In this position of the ruler, the angle between the 90° stroke and the thread is determined using the protractor scale. This angle is equal to the steepness of the slope. The average error in measuring the slope steepness using this method is 2-3°.
§ 1.4.4. Linear measures
- Arshin = 0.7112 m
- Versta = 500 fathoms = 1.0668 km
- Inch = 2.54 cm
- Cable length = 0.1 nautical mile = 185.3 m
- Kilometer = 1000 m
- Line = 0.1 inch = 10 points = 2.54 mm
- Lieu ( France) = 4.44 km
- Meter = 100 cm = 1000 mm = 3.2809 feet
- nautical mile ( USA, England, Canada) = 10 cables = 1852 m
- Statutory mile ( USA, England, Canada) = 1.609 km
- Fathom = 3 arshins = 48 vershoks = 7 feet = 84 inches = 2.1336 m
- Foot = 12 inches = 30.48 cm
- Yard = 3 feet = 0.9144 m
§ 1.4.5. Target designation on the map and on the ground
Target designation is a brief, understandable and fairly accurate indication of the location of targets and various points on the map and directly on the ground.
Target designation (indication of points) on the map is carried out using coordinate (kilometer) or geographic grid squares, from a landmark, rectangular or geographic coordinates.
Target designation using coordinate (kilometer) grid squares
Target designation by grid squares (Fig.4.12- A). The square in which the object is located is indicated by the signatures of kilometer lines. First, the bottom horizontal line of the square is digitized, and then the left vertical line. In a written document, the square is indicated in brackets after the name of the object, for example, high 206.3 (4698). During an oral report, first indicate the square, and then the name of the object: “Square forty-six ninety-eight, height two hundred six and three”
To clarify the location of the object, the square is mentally divided into 9 parts, which are designated by numbers, as shown in Fig. 4.12- b. A number specifying the position of the object inside the square is added to the designation of the square, for example, observation point (46006).
In some cases, the location of the object in The square is specified in parts, designated by letters, for example, barn (4498A) in Fig. 4.12- V.
On a map covering an area extending from south to north or from east to west for more than 100 km, the digitization of kilometer lines in double digits may be repeated. To eliminate uncertainty in the position of the object, the square should be designated not by four, but by six digits (a three-digit abscissa and a three-digit ordinate), for example, locality Lgov (844300) in Fig. 4.12- G.
Target designation from a landmark . With this method of target designation, the object is first named, then the distance and direction to it from a clearly visible landmark and the square in which the landmark is located, for example command post- 2 km south of Lgov (4400) in Fig. 4.12- d.
Target designation by geographic grid squares . The method is used when there is no coordinate (kilometer) grid on the maps. In this case, the squares (more precisely, trapezoids) of the geographic grid are designated by geographic coordinates. First, indicate the latitude of the lower side of the square in which the point is located, and then the longitude of the left side of the square, for example (Fig. 4.13- A): « Erino (21°20", 80°00")" The squares of the geographic grid can also be indicated by digitizing the nearest outputs of kilometer lines, if they are shown on the sides of the map frame, for example (Fig. 4.13- b): « Dreams (6412)».
Target designation by geographic grid squares
Target designation with rectangular coordinates - the most accurate method; used to indicate the location of point targets. The target is indicated by full or abbreviated coordinates.
Targeting by geographic coordinates used relatively rarely - when using maps without kilometer grids to accurately indicate the location of individual remote objects. An object is designated by geographic coordinates: latitude and longitude.
Target designation on the ground carried out in various ways: from a landmark, from the direction of movement, according to an azimuthal indicator, etc. The method of target designation is chosen in accordance with the specific situation, so that it ensures the fastest search for the target.
From landmark . On the battlefield, clearly visible landmarks are selected in advance and assigned numbers or conventional names. Landmarks are numbered from right to left and along the lines from oneself towards the enemy. The location, type, number (name) of each landmark must be well known to the issuing and receiving target designation. When specifying a target, name the nearest landmark, the angle between the landmark and the target in thousandths, and the distance in meters from the landmark or position: “ Landmark two, thirty to the right, below one hundred - a machine gun in the bushes».
Subtle targets are indicated sequentially - first they name a clearly visible object, and then the target from this object: “ Landmark four, to the right twenty is the corner of the arable land, further two hundred is a bush, to the left is a tank in a trench».
With visual aerial reconnaissance the target from the landmark is indicated in meters on the sides of the horizon: “ Landmark twelve, south 200, east 300 - six-gun battery».
From the direction of movement . Indicate the distance in meters first in the direction of movement, and then from the direction of movement to the target: “ Straight 500, right 200 - BM ATGM».
Tracer bullets (shells) and flares . To indicate targets in this way, landmarks, the order and length of bursts (the color of the missiles) are established in advance, and an observer is assigned to receive targets with the task of observing the specified area and reporting on the appearance of signals.
§ 1.4.6. Mapping targets and other objects
Approximately. On the oriented map, landmarks or contour points closest to the object are identified; estimate the distances and directions from them to the object and, observing their relationships, plot on the map a point corresponding to the location of the object. The method is used when there are local objects shown on the map near the object.
By direction and distance. At the starting point, carefully orient the map and use a ruler to draw the direction to the object. Then, having determined the distance to the object, they plot it along the drawn direction on the map scale and obtain the object’s position on the map. If impossible graphic solution tasks measure the magnetic azimuth to an object and translate it into a directional angle, along which they draw a direction on the map, and then plot the distance to the object in this direction. The accuracy of mapping an object using this method depends on errors in determining the distance to the object and drawing the direction to it.
Drawing an object on a map using a straight line
Straight serif. At the starting point A(Fig. 4.14) carefully orient the map, sight along the ruler at the object being identified and draw the direction. Similar actions are repeated at the starting point. IN. The point of intersection of two directions will determine the position of the object WITH on the map.
In conditions that make it difficult to work with the map, magnetic azimuths to the object are measured at the starting points, and then the azimuths are converted into directional angles and directions are drawn on the map using them.
This method is used if the object being determined is visible from two initial points accessible for observation. The average error of the position on the map of an object plotted with a direct notch relative to the initial points is 7-10% of the average distance to the object, provided that the angle of intersection of the directions (the notch angle) is within the range of 30-150°. At notch angles less than 30? and more than 150°, the error in the object’s position on the map will be significantly greater. The accuracy of drawing an object can be slightly increased by notching it from three points. In this case, when three directions intersect, a triangle is usually formed, the central point of which is taken as the position of the object on the map.
Gasket. The method is used in cases where the object is not visible from any contour (origin) point, for example in a forest. At the starting point, located as close as possible to the object being determined, the map is oriented and, having outlined the most convenient path to the object, the direction to some intermediate point is drawn. In this direction, the corresponding distance is laid off and the position of the intermediate point on the map is determined. From the resulting point, using the same techniques, they determine the position on the map of the second intermediate point and then, using similar actions, determine all subsequent points of travel to the object.
In conditions that exclude working with a map on the ground, first measure the azimuths and lengths of all traverse lines, write them down and at the same time draw a traverse diagram. Then, under suitable conditions, using these data, having converted magnetic azimuths into directional angles, the course is plotted on the map and the position of the object is determined.
Mapping an object using a compass track
If a target is detected in the forest or in other conditions that make it difficult to determine its location, the move is made in the reverse order (Fig. 4.15). First from the observation point A determine the azimuth and distance to the target C, and then from the point A make their way to the point D, which can be unmistakably identified on the map. In this case, the azimuths of the traverse lines are converted to reverse azimuths, and the azimuths are converted to directional angles, and the traverse from a fixed point is plotted on the map using them.
The average error in plotting an object on a map using this method when determining azimuths with a compass and distances in steps is approximately 5% of the traverse length. Example integrated use The above methods of mapping targets may be an episode of reconnaissance group actions - the action diagram is shown in Fig. 4.16.
Reconnaissance group action plan
1 – location Abkhazian militia; 2 – posts of Georgian formations; 3 – combat protection of Georgian formations; 4 - combat guard of Abkhaz militias; 5 – reconnaissance patrol of the group at the point of taking coordinates; 6 – reconnaissance group; 7 – equipment of Georgian formations; 8 – location Georgian formations
Taking advantage of the pre-dawn twilight, the reconnaissance group returned after completing its mission to the territory occupied by the Abkhaz militia. Unexpectedly, when approaching the forward posts of the Georgian formations, the group came across an enemy outpost.
Having penetrated the military outpost, the group commander decided to conduct additional reconnaissance of this area. For this purpose, a reconnaissance patrol was assigned with the task of examining the area adjacent to the road to Batumi.
While carrying out the task, the reconnaissance patrol discovered a concentration of enemy manpower and equipment on the slope above the road. The sergeant (senior reconnaissance patrol), taking into account the difficulty of determining the coordinates of the enemy’s location in the current conditions (the terrain is sharply rugged and overgrown with dense forest, poor visibility in the pre-dawn twilight), determined the coordinates according to the following scheme. Being at a distance of 80-90 m from the enemy’s position, and having determined that there was no more than 50-70 m from the center of the location to the immediate guard, the sergeant with a patrol climbed up the slope (approximate azimuth - 0°), bringing his position to 100 m from direct security. Then, taking the azimuth so that the directional angle when plotting on the map was equal to 0°, he began to climb the slope to the ridge of the spur, counting a couple of steps - when reaching the ridge, it turned out that the patrol had covered about 300 m. Taking into account the steepness of the slope, I determined the direct distance to the enemy's center ( rice. 4.16, image in a circle): 250+100+70=420 m.
On the crest of the spur at the end of the azimuth traveled, a tree was chosen, climbing which the sergeant tried to determine the point of his standing. To the northwest of this point, against the background of the brightening pre-dawn sky, a tower marked on the map, located on one of the peaks of the ridge, was clearly projected.
Realizing that this landmark alone was not enough to determine the point of his standing, the sergeant began to look for additional landmarks indicated on the map, and found a landmark in the form of a road bridge to the southwest. Taking the azimuth to the tower, I translated it into a directional angle, and, subtracting 180°, laid it until it intersected with the crest of the spur, thereby obtaining fairly accurate coordinates of my standing point. All that remained was to make a directional angle of 180° to the enemy’s location and set aside the already calculated distance - 420 m.
Having joined the group, the sergeant reported to the commander the calculated coordinates of the target. The commander, assessing the reliability of the information and the correctness of the calculations, decided to direct fire from his artillery. After the first sighting shot, the crew of the 120-mm mortar at the disposal of the Abkhaz militia fired a series of 6 mines, clearly hitting the enemy’s location.
I think there is no need to analyze in detail within the framework of this article why in shooting it is necessary to know the distance to the target: shooters and just readers interested in shooting know perfectly well that a bullet fired from firearms, does not fly in a straight line, but describes an arc along a flat trajectory, and its excess depends on the elevation angle of the weapon, specified for different distances. Therefore, let’s immediately move on to the issue that interests us, without venturing into the territory of external ballistics.
Not every shooter thinks about how to independently determine the distance to the target, and this is understandable. For example, in such a popular shooting discipline as practical shooting, distances to targets, although they can reach several hundred meters, are either known in advance or have no of great importance. Rifle athletes hit black circles with small-caliber rifles at a distance of 50 m - no more, no less. There’s no need to talk about stand-up shooters: fast, almost intuitive shooting with a shotgun at a flying saucer - there’s no time for checking distances. And in general, in indoor shooting ranges and at open shooting ranges, as a rule, boards with targets are placed at equal intervals at a designated distance. This is convenient and allows you to focus on making quality shots from a comfortable, familiar distance.
But sooner or later, some shooters have a desire to go beyond the limits offered by shooting ranges and shoot at longer distances - for example, from . What is needed for this? First of all, of course, a suitable shooting range with a length of up to 1000-1200 meters.
And although there are many such shooting ranges in Russia, let’s imagine that you find yourself at such a facility.
What do you see? Most likely, rows of shields with targets, and gongs placed throughout the field. And if the first ones, as a rule, are installed at fixed and designated distances and therefore are not of interest within the framework of this article, then the second ones - those same small-sized, coveted targets that respond to a hit with a characteristic ringing - are placed at an unknown distance, and I propose to talk about them more details. To hit such a gong you need to know the distance to it. Wind, air temperature, pressure, etc. - this is all secondary. The first most important thing is the distance to the target, for which it is necessary to make adjustments in the sight. How to define it?
Three common ways to determine the distance to a target
Method #1 - determining the distance “by eye”
The first method is the most, literally, obvious. But once you try, you will understand that this task is not easy. Your vision, your eye level of training, lighting conditions, terrain, and even the color of your target will all make your best guess at distance too far off. What does too big mean? Let's figure it out.
Let's say the gong is actually at a distance of 580 meters, and you are off on your estimate by 10 meters more or less, which is very good for a naked eye measurement. Even with such a small error, the probability of a miss is high. Why? Judge for yourself. Gongs for high-precision shooting are rarely larger than half a thousand, which means that the height of our target is no more than 30 cm. The trajectory of a bullet from one of the most popular rifle calibers - .308 Win - at distances of 570-590 meters will vary in height by approximately 15 -20 centimeters every 10 meters, which is equal to half the size of the target. Thus, if you shoot at the center of such a gong at 580 meters, having previously set the correction on the sight to 570 or 590 meters (depending on which direction you were mistaken in assessing the distance), you will most likely miss, since your bullet will pass by 15-20 cm below or above the aiming point.
What if the error in determining the distance is not 10, but 20 or 30 meters? Or is the gong even further away? In this case, the shooting will go almost at random with the hope of an accidental hit.
Method #2 - based on the known dimensions of the “target”
I’ll immediately make a reservation that in the second method of determining the distance to the target there is one condition: you must know the size of the target - height or width. Using your scope's reticle, you measure in thousandths the size you know, and then calculate the distance to the target in meters by dividing the size of the target in millimeters by its size in thousandths. Let's for clear example Let's take our 30 cm gong. Its height on the sight reticle was 0.517 thousandths. We divide 300 (the height of the gong in millimeters) by 0.517 and we get 580.27 meters, which is very close to the truth.
Does anything bother you about this method? No, I don't mean mental division skills - after all, you can do the calculations using a calculator on your phone. This is what confuses me: in my experience, it is extremely difficult to determine with such accuracy the size of a target in thousandths using a scope reticle - there will definitely be an error. For example, without seeing 0.017 thousandths in the scope and taking half a thousandth as the size, I will get the distance to the target not 580, but 600 meters. I explained above what this will lead to.
Method #3 - high-precision
His Majesty will help us with it Laser rangefinder. “Their Majesties” are different: from budget hunting ones for 15 thousand rubles to exclusive tactical ones for 800 thousand rubles. If no questions arise about the latter, except for two - high price and relatively big size, then it’s worth understanding the rest in more detail and talking about several, in my opinion, important aspects of their use.
Measuring range
Let's immediately discard the rangefinders from maximum range measurements are smaller than the effective range of our rifle: why do we need a rangefinder at 500 meters if our rifle can hit, for example, up to 1000 meters? With a maximum range that is much greater than the capabilities of our caliber, it also makes no sense to be greedy: targets at distances where a bullet is guaranteed to “not reach” are no longer targets, but simply objects of observation. Better take binoculars.
Size
The size of the rangefinder should, on the one hand, be small so that it is comfortable to wear, but on the other hand, it should allow measurements to be taken while holding the rangefinder with both hands - this way vibrations of the device will be minimal. But no one, even the most confident hands, can replace a tripod: take a rangefinder with a tripod mount.
Built-in Ballistic Calculator (BC)
Manufacturers of mid-priced rangefinders often provide them with built-in ballistic calculators, promising to tell the shooter the amount of required vertical correction for the measured distance. It is important to understand that you should not fully rely on such data: built-in BCs are based on average trajectories for the most popular calibers without reference to atmospheric conditions. If your target is the front of a barn, you'll probably hit it; if you need to shoot at a small-sized gong, you cannot do without a serious and correct ballistic calculator, but this is a subject for another discussion.
Measurement techniques
Having decided on a rangefinder, let's try it out and measure the distance to the target - for example, the distance to that gong over there. We point the rangefinder at the target, hold, press (or press, depending on the model of the device) the button. Happened? No? If the rangefinder is treacherously silent, there can be two main reasons:
- Instrument instability during measurement
The signal must have time to reflect from the target and be considered a rangefinder detector, so vibrations of the device must be minimized. I mentioned a tripod above. You can also use a wall, a pole, a tree trunk as a support - anything that will allow you to keep the device as motionless as possible. If the situation allows it, lie down. When lying down, there is less fluctuation when shooting and when measuring distances. - Small target size
How smaller size target, the less reflective it is. We, as you remember, did not purchase an expensive tactical rangefinder, the measurement of which is similar to pointing a point at a target with a laser pointer, but a more modest model. But our device can also have such a useful function as scanning: while holding down the measurement button, move the device along the front of the target and monitor its readings. If this does not help, take a closer look at what is on the flanks of the target or immediately behind it. Any reflective surface - a pile of sand, wood, etc. — will allow you to calculate the distance. Do you see anything similar next to the gong?
There are no hopeless situations
If circumstances allow, use reverse measurement - get in the car, drive to the target and measure the distance from it to the firing line. After all, as has been experimentally established many times, the distance to the target is equal to the distance from the target to the firing line.
Good luck with your measurements and accurate shots!
We often hear that shooters simply do not know how to determine the distance to the target (target) at which they need to shoot. And this despite the fact that an optical sight is installed on the rifle or shotgun (carbine). In general, the topic of optical sights is very common in questions on forums and letters from readers. The main issues are reticles and distances to the object of observation. Which reticle is best for long range shooting? Why big ones? Yes, because at a distance of 10 to 20 m it is easier to use a red dot sight. I decided to organize some information regarding optics and distance.
A simple method for determining the distance to an object
In the picture below you can see the aiming reticle Rangefinder, or as it is popularly called - “crossbow net”. Sights with this type of reticle have become very popular among owners of weapons with optical sights. A convenient scale for calculating distances and at the same time auxiliary crosshairs allow you to very accurately calculate the distance to the target, making certain adjustments. The figure clearly shows how you can determine the distance to the target using the example optical sight 4x32.
Visual determination of the distance to the target using an optical sight
(Rangefinder reticle, or crossbow reticle)
It is worth noting that the setup and preliminary calibration of each sight must be carried out separately. This should be done as follows:
- take a “standard” with a vertical and horizontal dimension of 50 cm (for example, a cardboard box),
- set the scope magnification to 4 (if you have a scope with variable magnification) and look at the “standard” through the optical sight from a distance of 30 m. Usually at this distance 0.5 meters of width is placed between the curves at the level of the central crosshair.
If the “standard” does not fit between the curves or, on the contrary, is much smaller, then you need to change the distance to the target until you achieve the desired result. Remember this distance, or better yet, make a note to yourself so that later, when needed, you can quickly calculate the distance to the target.
In the same way, we find the distances corresponding to all other aiming marks on the reticle. After this, you can begin to zero in the sight. “Why not the other way around?” - you ask. Yes, because it is easier to sight the sight at already known distances. Now, looking at your hunting object through an optical sight, you will know exactly the distance to the target.
Such sights can be installed on air guns and firearms.
To approximately determine the distance, a sniper or shooter can use the following simplest methods.
An eye-based method for determining the distance to a target
To hit the target with the first shot, you need to know the distance to it. This is necessary for correct definition correction values for side wind, air temperature, Atmosphere pressure and, most importantly, to install the correct sight and select the aiming point.
The ability to quickly and accurately determine the distance to stationary, moving, and also appearing targets is one of the main conditions successful work sniper 
Rice. Proportional perception of the target by the sniper with the reticle of the PSO-1 sight for the development of automatic skills in determining the range
The main one, the simplest and fastest, most accessible to a sniper in any combat situation. However, a sufficiently accurate eye is not acquired immediately; it is developed through systematic training, carried out in a variety of terrain conditions, in different times year and day. To develop your eye, you need to more often practice estimating distances by eye, necessarily checking them in steps and on a map or in some other way.
First of all, you need to learn to mentally imagine and confidently distinguish several distances that are most convenient as standards on any terrain. You should start training with short distances (10, 50, 100 m). Having mastered these distances well, you can move successively to larger ones (200, 400, 800 m) up to the maximum range of actual fire sniper rifle. Having studied and consolidated these standards in visual memory, you can easily compare with them and evaluate other distances.
During such training, the main attention should be paid to taking into account side effects that affect the accuracy of the visual method of determining distances:
1. Larger objects seem closer than small ones located at the same distance.
2. Objects that are visible more sharply and clearly seem to be closer together, therefore:
- objects of bright colors (white, yellow, red) seem closer than objects of dark colors (black, brown, blue),
- brightly lit objects seem closer to dimly lit ones that are at the same distance,
- during fog, rain, at dusk, on cloudy days, when the air is saturated with dust, observed objects seem further away than on clear sunny days,
- the sharper the difference in the color of objects and the background against which they are visible, the more reduced the distances to these objects seem; for example, in winter, a snow field seems to bring all the darker objects on it closer.
3. The fewer intermediate objects are between the eye and the observed object, the closer this object seems, in particular:
- objects on level ground seem closer,
- distances defined through vast open water spaces seem especially shortened; the opposite shore always seems closer than in reality,
- folds of the terrain (ravines, hollows) crossing the measured line seem to reduce the distance,
- when observing while lying down, objects seem closer than when observing while standing.
4. When observed from bottom to top, from the bottom of the mountain to the top, objects appear closer, and when observed from top to bottom, they appear further away.
Visibility of objects at different distances:
| Distance (km) | Item |
| 0,1 | Human facial features, hands, details of equipment and weapons. Collapsed plaster, architectural decorations, individual bricks of buildings. The shape and color of leaves, the bark of tree trunks. Wire fencing and personal weapons: pistol, rocket launcher. |
| 0,2 | General facial features, general details of equipment and weapons, the shape of the headdress. Individual logs and boards, broken windows of buildings. Tree leaves and wire on the supports of a wire fence. At night - lit cigarettes. |
| 0,3 | The oval of a person’s face, the colors of clothes. Details of buildings: cornices, platbands, drainpipes. Light infantry weapons: rifle, machine gun, light machine gun. |
| 0,4 | Headdress, clothes, shoes. Living figure in general outline. Frame bindings in building windows. Heavy infantry weapons: AGS, mortar, heavy machine gun. |
| 0,5-0,6 | The contours of a living figure are clear, the movements of the arms and legs are distinguishable. Large details of buildings: porch, fence, windows, doors. Tree branches. Wire fence supports. Light artillery: LNG, ZU, BO, heavy mortar. |
| 0,7-0,8 | A living figure - a general outline. The chimneys and attic windows of the buildings are distinguishable. Large tree branches. Trucks, combat vehicles and tanks standing still. |
| 0,9-1,0 | The outlines of a living figure are difficult to discern. Stains on building windows. The lower part of the trunk and the general outline of trees. Telegraph poles. |
| 2,0-4,0 | Small detached houses, railway carriages. At night - lit lanterns. |
| 6,0-8,0 | Factory chimneys, clusters of small houses, large individual buildings. At night - the headlights are on. |
| 15,0-18,0 | Large bell towers and large towers. |
Determining the distance to the target by angular dimensions
Determining the distance to a target by angular dimensions is possible if the observable linear value (height, width or length) of the object to which the distance is determined is known. The method comes down to measuring the angle in thousandths at which this object is visible.
The thousandth is 1/6000 part of the circular horizon, increasing in width in direct proportion to the increase in the distance to the reference point, which is the center of the circle. For those who have a hard time understanding, remember that the thousandth is in distance:
100 m = 10 cm,
200 m = 20 cm,
300 m = 30 cm,
400 m = 40 cm, etc.
Knowing the approximate linear dimensions of a target or landmark in meters and the angular magnitude of this object, you can determine the distance using the thousandth formula: D = (H x 1000)/U,
Where D- distance to target
1000
- a constant, unchangeable mathematical quantity that is always present in this formula
U- the angular magnitude of the target, that is, to put it simply, how many one-thousandth divisions on the scale of an optical sight or other device will the target occupy
IN- metric (that is, in meters) known width or height of the target.
For example, a target is detected. It is necessary to determine the distance to it. What are the actions?
1. Measure the target angle in thousand.
2. The size of the object located next to the target in meters, multiply by 1000
3. Divide the result obtained by the measured angle in thousand.
The metric parameters of some objects are:
| An object | Height (m) | Width (m) |
| 0,25 | 0,20 | |
| 0,25 | 0,25 | |
| Human | 1,7-1,8 | 0,5 |
| crouching man | 1,5 | 0,5 |
| Motorcyclist | 1,7 | 0,6 |
| Passenger car | 1,5 | 3,8-4,5 |
| Truck | 2,0-3,0 | 5,0-6,0 |
| Railway car on 4 axles | 3,5-4,0 | 14,0-15,0 |
| Wooden pillar | 6,0 | - |
| Concrete pillar | 8,0 | - |
| Cottage | 5,0 | - |
| One floor of a multi-storey building | 3,0 | - |
| Factory pipe | 30,0 | - |
The scales of open sights, optical sights and optical instruments available in service are graduated in thousandths and have a division value: 
Thus, to determine the distance to an object using optics, it is necessary to place it between the scale divisions of the sight (device) and, having found out its angular value, calculate the distance using the above formula.
Example, you need to determine the distance to the target (chest or height target), which fits into one small side segment of the scale of the PSO-1 optical sight.
Solution, width of the chest or height target (infantryman in full height), equal to 0.5 m. According to measurements using PSO-1, the target is covered by one division of the lateral correction scale, i.e. angle 1 thousandth.
Hence: D=(0.5 x 1000)/1=500m.
Measuring angles using improvised means
To measure angles with a ruler, you need to hold it in front of you, at a distance of 50 cm from the eye, then one of its divisions (1 mm) will correspond to 0-02.
The accuracy of measuring angles using this method depends on the skill in placing the ruler exactly 50 cm from the eye. You can practice this using a rope (thread) of this length.
To measure angles with improvised objects, you can use your finger, palm or any handy tool. small item(matchbox, pencil, 7.62 mm sniper cartridge), the dimensions of which in millimeters, and therefore in thousandths, are known. To measure the angle, such a measure is also placed at a distance of 50 cm from the eye, and from it the desired angle value is determined by comparison.
The angular dimensions of some objects are:
Having acquired skills in measuring angles, you should proceed directly to determining distances based on the measured angular dimensions of objects.
Determining distances by the angular dimensions of objects gives accurate results only if the actual dimensions of the observed objects are well known, and angular measurements are made carefully using measuring instruments (binoculars, stereo scopes).
Application of the thousandths formula in shooting practice
To determine firing distances using the “thousandths” formula, it is necessary to know exactly in advance the width or height of the object (target) to which the distance is being determined, determine the angular value of this object in thousandths using available optical instruments, and then calculate the distance using the formula, where:
D is the distance to the object in meters;
Y is the angle at which the object is visible in thousandths;
B is the metric (that is, in meters) known width or height of the target.
1000 is a constant, unchangeable mathematical value that is always present in this formula.
When determining the distance in this way, you need to know or imagine the linear dimensions of the target, its width or height. The linear data (sizes) of objects and targets (in meters) in infantry combined arms practice are accepted as follows.
|
Height, m |
Width, m |
|
|
Infantryman: full length |
||
|
Running crouched |
||
|
Turned sideways |
||
|
Telegraph pole: wooden |
||
|
Concrete |
||
|
One-story house, gray |
||
|
One floor of a large-panel house |
||
|
Four-axle car: freight car |
||
|
Passenger |
||
|
Car: |
||
|
Freight |
||
|
Passenger car |
||
|
Without a helmet |
||
|
Construction brick |
thickness 6-7 cm |
length 25 cm end 12 cm |
For example, you need to determine the distance to the target (chest or height target), which fits into two small side segments of the scale of the PSO-1 optical sight, or is equal to the thickness of the aiming stump of the PU sight, or is equal to the thickness of the front sight of an open rifle sight. The width of the chest or height of the target (full-length infantryman), as can be seen from the table. 6, equal to 0.5 m. For all measurements of the above sighting devices(see below) the target is covered by an angle of 2 thousandths. Hence:
But the width of a live target may be different. Therefore, the sniper usually measures the width of the shoulders in different times year (by clothing) and only then accepts it as a constant value. You need to measure and know the main dimensions human figure, linear dimensions of the main military equipment, vehicles and everything that can be “attached” to on the side occupied by the enemy. And at the same time, all this should be viewed critically. Despite laser rangefinders, the determination of ranges in combat practice of the armies of all countries is carried out according to the above formula. Everyone knows about it and everyone uses it, and therefore they try to mislead the enemy. There have been numerous cases when telegraph poles were secretly increased by 0.5 m at night - during the day this gave the enemy an error in calculating the range of 50-70 meters of shortfall.
Angular values in thousandths of available objects and devices
To measure the angular values of targets in thousandths, the most commonly used objects are used, which in combat practice are often at hand. Such items and means are parts of open sights, sighting threads, marks, reticles of optical sights and other optical devices, as well as everyday items that are always available to a soldier - cartridges, matches, ordinary scale metric rulers.
As mentioned earlier, the width of the front sight covers an angle of 2 thousandths in the projection onto the target. The height of the front sight covers 3 thousandths. The base of the sight - the width of the slot - covers 6 thousandths.
As mentioned earlier, the width of the aiming stump covers an angle of 2 thousandths in the projection onto the target. The horizontal threads cover the angles in their thickness by also 2 thousandths. Sight base
A - the distance between the threads - covers 7 thousandths.
For PSO-1:
A - main square for shooting up to 1000 m,
B - three additional squares for shooting at distances of 1100, 1200, 1300 m;
B - the width of the lateral correction scale from 10 to 10 thousandths corresponds to 0-20 (twenty thousandths),
G - from the center (main square) right-left to the number 10 corresponds to 0.10 (ten thousandths) The height of the extreme vertical mark at the number 10 is 0.02 (two thousandths);
D - the distance between two small divisions is 0.01-1 (one thousandth), the height of one small mark on the lateral correction scale is 0.01 (one thousandth);
E - numbers on the rangefinder scale 2, 4, 6, 8, 10 correspond to distances of 200, 400, 600, 800 and 1000 m;
F - the number 1.7 shows that at this level of the height scale the average human height is 170 cm.
Measurements in thousandths of the binocular and periscope reticle:
- from a small risk to a large risk (short distances), an angle of 0.05 (five thousandths) is covered;
- from large risk to large risk, an angle of 0.10 (ten thousandths) is covered.
The height of the small risk is 2.5 thousandths.
The height of the large risk is 5 thousandths.
Cross bars - 5 thousandths.
When using improvised means to determine angular values, they are placed at a distance of 50 cm from the eye. This distance has been verified over many decades. At a distance of 50 cm from the eye, the rifle cartridge and matches close the angles indicated below in projection onto the target.
1 centimeter of an ordinary scale ruler (better if it is made of transparent material) at a distance of 50 cm from the eye covers an angle of 20 thousandths; 1 millimeter, respectively, 2 thousandths.
Prudent shooters determine in advance a goniometric distance of 50 cm for possible determination of distances based on the angular values of available objects. Usually for this purpose they measure 50 cm on the rifle and mark it.
D = N (number of pairs of steps) * L (length of pairs of steps);
- on the map:
- on the rangefinder scale:
To determine the distance on the rangefinder scale, it is necessary to point the scale at the target so that the target is located between the solid horizontal and inclined dotted lines. The scale bar located above the target indicates the distance to the target, which has a height of 1.7 m. If the target has a height less (greater) than 1.7 m, then the distance determined on the scale must be multiplied by the ratio of the target height to 1.7 m.
Example:
Determine the distance to an object having a height of 0.55 m if the upper part of the object touches the dotted line of the rangefinder scale with a stroke marked with the number 8.
Solution:
The ratio of the target height to 1.7 m is equal to rounded 1/3 (0.55: 1.7); the scale indicates a distance of 800m: the distance to the target is approximately 270m. (800*1/3)
The distance on the rangefinder scale can only be determined when the target is visible in full height. If the target is completely invisible in height, then determining the distance to it in a similar way can lead to gross errors (the ranges will, as a rule, be overestimated);
- according to the thousandth formula:
At a distance of 100 meters from the shooter, one thousandth along the horizon occupies a distance of 10 cm, at 200 m - 20 cm, at 300 m - 30 cm, at 400 m - 40 cm, and so on. At a distance of 1 km, one thousandth is equal to 1 meter.
Thousands are written and read accordingly as follows:
one thousandth - 0.01 - zero, zero one;
six thousandths - 0.06 - zero, zero six;
25 thousandths - 0.25 - zero, twenty-five;
130 thousandths - 1.30 - one, thirty;
1500 thousandths - 15.00 - fifteen, zero zero.
Measuring angles in thousandths can be done with the goniometer circle of an artillery compass, the reticle of binoculars and periscopes, the lateral correction scale and the dials of the flywheel of a sniper scope, as well as improvised objects. The compass has a scale on a circle, divided into large divisions of 1-00 and small divisions of 0-20. Binoculars and periscopes have reticles divided into large divisions of 0-10 (ten thousandths) and small divisions of 0.05 (five thousandths). Machine gun and sniper sights have divisions of 0.01 (one thousandth).
To determine the distance using the “thousandth” formula, you need to know the linear dimensions of the target (local objects). The angular magnitude of the target (local objects) is measured using the lateral adjustment scale of the sight reticle or the angular magnitude scale of the binoculars:
D = (W * 1000) / Y, where
D - distance to target in meters;
W - height (width) of the target in meters;
Y - angular value of the target in thousandths (target size in thousandths).
