Range Estimation
For most vehicles represented in Steel Beasts Professional the LRF (laser range finder) is the principal means of determining range to distant targets or objects. Unfortunately, malfunctions, environmental conditions, or target size, along with the vehicle lacking an LRF to begin with, may force the crew to use an alternate method of range determination.
The purpose of this article is to explain how to determine range using these alternate methods. Such methods vary from the simple and quick recognition method to the more complex, time-consuming, but accurate mil relation formula. Other methods include reticle relationship, ranging with the TC’s machine gun (M1, M1A1, M60A3 ect.), flash-bang, adjacent vehicles, known range, two tank intersection (M60A3 and Leopard 1), and map. Each method is based on varying situations, conditions, and degrees of accuracy and should be practiced at every opportunity.
For simplicity, these techniques can be divided into two broad categories: Immediate and Deliberate range determination methods. We will explore each of these below.
Contents
Immediate Range Determination Methods
Recognition Method
With practice, range determination by recognition is quick and relatively accurate; however, due to the simulated nature of the environment in Steel Beasts Professional, this method is not as effective as in reality, nor will it work with passive/active IR or thermal sights. The principle of the recognition method is simple: when the TC sees a target, he can determine the range according to what he recognizes. For example, in SB if a target can be recognized as a tank with the unaided eye, it is within 800 meters; if a target can be recognized as a tank through magnifying optics (GAS, binoculars, and so forth), it is within 3,000 meters.
The following table gives range estimations for targets as seen in Steel Beasts Professional with the unaided eye and through magnifying optics (binoculars).
Target | Unaided Eye (meters) | Magnified View (7-8x) |
---|---|---|
Tank crew, troops, machine gun, mortar, antitank gun, antitank missile launchers | 500 | 2000 |
Tank, personnel carrier, truck (by model) | 500 | 1500 |
Tank, howitzer, personnel carrier, truck | 800 | 3000 |
Armored vehicle, wheeled vehicle | 1000 | 5000 |
Stadiametric Rangefining
Many vehicles simulated in Steel Beasts feature some form of stadiametric rangefinding. This type of rangefinder either features a descending horizontal stadia scale which is used to bracket a target and determine its range based on the target's height, or a vertical “range funnel” which functions in a similar manner but uses target width instead. The numbers on these scales represent the range to the target in hundreds of meters. These rangefinders typically are only accurate within 100m as they rely on an “average” enemy vehicle height/width, but are faster than more deliberate ranging techniques. Below is a demonstration of stadiametric rangefinding using the M1 series GAS stadia reticle as an example.
Reticle Relationship Method
This method is a combination of range estimation and an engagement technique. It provides the TC or gunner a rapid, accurate alternate method of determining range to a target and successfully engaging the target, and is based on an average enemy tank with the following dimensions:
- Width 3.4 meters.
- Height 2.3 meters.
- Length 6.7 meters.
When the reticle of either the GPS or GAS is superimposed over the enemy tank, the properly trained gunner or TC can rapidly determine if the target is within a preselected battlesight range, or if further range determination is required.
Note that the SABOT and HEAT reticles on the M1 and M60 series GAS do not have established vertical mil values, therefore using a vertical measurement is not recommended.
Tank Commander’s Machine Gun Method
On the M60A3, M1, M1IP, M1A1, and M1A1HA tanks the TC’s machine gun can be used to determine range. For the M60A3, ranging fire can be used out to 2000m, while the M1 series is limited to 1800m. To aid the gunner in target identification and to reduce engagement time, the machine gun should be aligned with the main gun. One advantage in using the TC’s machine gun is to suppress the target while determining range at the same time. The disadvantage of this method is that the tank’s position will be disclosed.
To use this method in SB, the TC places his sight reticle aiming point on the target, and fires. He then observes the tracers and adjusts their impact until they strike the target. Once the tracers impact on, or near, the target, the TC reads the corresponding aiming point of the reticle and either:
- Announces the range to the gunner (if a human gunner is present), and has him manually index the range or engage with the GAS.
- Manually indexes the range using the battlesight button (on the M1) or, if relying on the AI gunner, jumps into the gunner's position and proceeds as above.
Deliberate Range Determination Methods
Mil Relationship Method
The mil relation method is one of the most accurate means of range determination. One mil equals a width (or height) of 1 meter at a range of 1,000 meters. The relationship of the angle, the length of the sides of the angle (range), and the width (height) between the sides remains constant. The figure below shows the constant relationship as the angle increases from 1 to 2 mils and the range increases from 1,000 to 2,000 meters.
Note: Tank fire control systems use mils (₥) to apply deflection and elevation corrections and measure angular velocity. One mil is equal to 1/6400 of a circle; there are approximately 17.8 mils in one degree.
- It should be noted that tank sight and binocular graticules on Russo/Soviet vehicles are marked in “Russian” mils. Russian mils subtend to 6000 mils in a circle rather than 6400. This leads to an approximate 7% difference in determined range values, but in practice this amount is too small to matter at battlefield ranges.
When determining range using the mil relation, the width, length, or height of the target must be known. Accuracy depends on knowledge of target dimensions and the ability of the individual to make precise measurements with the binoculars. Measure the width, length, or height with the binocular mil scale or a non-ballistic reticle, substitute the mil relation, and compute the range with the following formula:
Where R is the range to the target, W is the actual target width, and ₥ is the measured width in mils. Because the mil relation is constant, the formula may be converted to solve for other factors by removing the factor that is to be determined.
The mil relation holds true whether the W factor is in a horizontal or vertical plane, as long as the mil angle is measured in the same plane. Because the mil relation is constant, other units of measurement such as yards, feet, or inches may be substituted for meters in expressing width or range; however, the relation holds true only if both W and R are expressed in the same unit. For example, if the sides of a 1-mil angle are extended to 1,000 yards, the width between the ends of the sides is 1 yard.
The following formula should be used when looking at the tank from the side view. Example: A T-72 is approximately 6.7 meters long (W). Using binoculars, the TC determines that the tank he sees is 5 mils (₥) in length. Remove the R factor from the mil relation: W ÷ ₥ x 1,000. Substitute the two known values for W and ₥ and solve for R: R = 6.7 ÷ 5 = 1.34. Since R is in thousands of meters, multiply the answer 1.34 x 1,000 = 1,340 meters. This will be the range to the enemy tank.
This applies when looking at the tank from a frontal view as well. Example: A T-72 is approximately 3.3 meters wide (W). Using binoculars, the TC determines that the tank he sees is 2.5 mils (₥) wide. Remove the R factor from the mil relationship: W ÷ ₥ x 1,000. Substitute the two known values for W and ₥ and solve for R: R = 3.3 ÷ 2.5 = 1.32. Since R is in thousands of meters, multiply the answer 1.32 x 1,000 = 1,320 meters. This will be the range to the enemy tank.
Note that ballistic reticles, such as those found on Gunner Auxiliary Sights, generally do not have established vertical mil values, therefore using a vertical measurement with these sights is not recommended.
Minute of Angle Relationship Method
On some older vehicles simulated in Steel Beasts sight graticules may be marked in Minutes of Angle (MOA) rather than mils while ranges are displayed in yards. Considered by most a lost art in modern warfare, range determination using MOA is not all that different than using mils. The important thing to remember is that all measurements are made in inches and yards rather than in meters. Although simplified, it is commonly held that 1 MOA equals 1 inch at 100 yards. Therefore, if the length, width, or height in inches of a given target is known, then using the following formula one can quickly determine the range to the target.
Map Method
Perhaps the easiest deliberate method of range determination for Steel Beasts users, the F5 map can be be used to determine range to spotted enemy units. The TC finds his tank’s position and the target’s position on the in session map, then estimates the distance between the two points using the map's grid system. On vehicles equipped with tactical displays, this can be done “in cockpit” without having to switch to the F5 view.