DE102007007404A1 - Method and device for remote release of a projectile - Google Patents

Abstract

Method for remote triggering of at least one projectile (3) fired from a weapon (2) with a detonator (13) by a computer unit (6), in particular a fire control computer, to which a signal transmission unit (7), in particular a radio unit, is connected, in particular to Defense against flying assault ammunition, wherein by initiation by the computer unit (6) the signal transmission unit (7) emits remote control signals, wherein a signal receiving unit (8), in particular a radio unit of the projectile (3) receives the remote control signals and one to the signal receiving unit (8) connected ignition control unit (9) immediately after the correct reception of the remote control signals, the ignition by the igniter (13) initiated.

Description

The The invention relates to a method and a device for remote triggering at least one projectile fired from a weapon. she can For example, find use for protection against flying attack ammunition. In particular, flying assault ammo can Rockets and artillery and mortar rounds (so-called RAM threat) or cruise missiles, aircraft and parachute objects u. Ä. represent.

It Methods are known in which attempts are made against objects thereby protecting flying assault ammunition that the projectile with splinter effect in the direction of the previously located assault ammunition is fired in order to combat this before striking. Upon ignition of the projectile, this, in particular the shell, decomposed into a variety of splinters, caused by the explosion additionally accelerated. The spread of the splinters is usually cone-shaped. When the attack ammo meets a splinter, he can on the assumption that the splinters are of sufficient size and one has sufficient speed to pass through the hull of the assault ammunition body effectively combated become.

Such a method, together with the radar equipment required for locating is, for example, in the DE 44 26 014 B4 , of the DE 100 24 320 C2 , of the EP 1 518 087 B1 and the DE 600 12 654 T2 described. Shrapnel grenades are usually used as a projectile, which are fired with a launcher. An ammunition with splinter effect is for example in the DE 100 25 105 B4 and in the DE 101 51 897 A1 described. As locating devices for locating and tracking the attack ammunition and for determining the trajectory parameters of the attack ammunition body short-range radars, long-range radars and optical sensors are used.

at the known methods include the objects to be protected especially vehicles and facilities in the vicinity of the firing Weapon. As a close-up area here is a radius of a few 100 m up to a maximum of 500 m. In addition going Remote methods can not be used. This is u. a. substantiated in that in the procedures used typical fragment grenade launcher are only able to grenades with a firing speed of a few 100 m / s firing. These can thus be effective only in the vicinity, as with increasing distance the speed and thus the energy of the Projectiles, which influence the energy of the splinters and which thus for a successful fight against the attack ammunition necessary, decreases sharply.

The known methods are thus disadvantageous because they do not or only at great expense for the protection of spatial extended objects can be used. For example to protect a field camp the area of a few square kilometers, would have a very large number of Werfer set up become. Furthermore, in the known methods used Defense ammunition only against special attack ammunition effective, for example against anti-tank ammunition or against missiles, so that protection against all assault ammunition not given is.

moreover is a fight at close range disadvantageous, as this the danger entails that by fighting itself, for example, by splinters, damage the objects to be protected takes place. Further, the problem may be that occur in an unsuccessful fight the time of another attempt to combat too short is.

adversely in the known method is also that the fragmentation grenades be tempiert before firing, d. H. the ignition point is determined before firing and given to the fragmentation grenade. The disadvantage here is that u. a. due to the tolerances of Weapon, the propellant charge, and the ammunition a scatter of shot development time the time from closing the contact to the ignition the primer cartridge or - with howitzers - until includes the exit of the projectile from the mouth, or the ballistic dispersion is present, so that the appointed time most likely not the optimal time for the ignition is because, for example, the defense ammunition at the time of ignition far from the assault ammunition can be removed. Tolerable results can be achieved again achieve only at close range, as in the fight in the long-range Inaccuracies, such as an angle error, to significantly higher absolute deviations of the distance between the attack ammunition and projectile at the time of ignition.

Also known is an embodiment in which the defense ammunition body has a proximity fuse. The disadvantage here, however, is that the setting of the correct triggering distance is critical. Further, the assault ammunition can be very small, whereas the determined probable common space may be large due to the inaccuracies of the sensors and the scatters, so that there is a high probability of failure of proximity ignition. In addition, the active sensors, such as an active radar, or the passive sensors, such as an infrared sensor, the proximity fuse can be disturbed by the opponent, whereby ignition can be prevented.

The However, the invention is not limited to the use for combat limited by assault ammunition. she can generally used for remote triggering of projectiles.

The EP 1 742 010 A1 describes a non-lethal bullet with a programmable and / or adjustable detonator. The non-lethal ammunition can act here, inter alia, by electromagnetic impulses, color, chemical irritants, fog or the like. All applications are equal, that in particular no persons should come to harm by the projectile. For this reason, a detonable detonator is used so that the presence of bullets does not nullify non-lethality.

The DE 10 2005 024 179 A1 describes without specifying the specific applications, a method and an apparatus for temping and / or correction of the ignition timing of a projectile. Here, the velocity of a projectile is measured after firing. The measurement is based on the muzzle velocity ge, which is then used to adjust and / or correct the Zündstellzeit. A particular disadvantage of the method is that further parameters which have an influence on the ignition time are not taken into account.

Known Bulletproof igniters are therefore particularly disadvantageous because on the one hand, the achievable accuracy is not sufficient. The triggering should be preferred within less than 1 ms. However, known artillery time fuses have an adjustable step size and thus a resolution of 100 ms with an accuracy of 3-30 ms. On the other hand the missile is programmed before loading the weapon. Thus is it is not possible with charged weapon on a possible missile attack to wait and thus save reaction time.

The The invention has for its object to provide a method and a device which the disadvantages of the ignition initiation at the floors of the Reduce prior art and especially effective for protection can be used against flying attack ammunition.

The Invention solves the problem procedurally with the features of claim 1 and device with the features of claim 20. A use of the device according to Claim 20 for protection against flying attack ammunition is part of claim 21. Advantageous developments are Component of the dependent claims.

It is a basic idea of the invention, the ignition of the detonator of the projectile by a computer unit, in particular a fire control computer, remotely trigger practically without time delay. Out For this reason, a signal transmission unit to the computer unit, in particular a radio unit is connected, which by initiation by the computer unit transmits remote control signals. The projectile points for receiving these remote control signals, a signal receiving unit, in particular a radio unit, on. To the signal receiving unit an ignition control unit is connected, which immediately after the correct reception of the remote control signals the ignition initiated by the detonator.

The Remote control signals may include a trigger code that of the ignition control unit to determine the correct Receiving the remote control signals are evaluated. The raised Safety can thus be achieved by the fact that only at the end the verification of the trigger code, the coincide with the triggering unit known release code must, directly the ignition is initiated.

Prefers becomes the trigger code when transferring the remote control signals modulated onto a carrier frequency.

Of the Trigger code can be at least one code word, in particular with a length of 52 to 256 bits. The longer the codeword is chosen the larger is safety during transmission and it can be prevented be that the opponent triggers a premature ignition, for example, guessing the trigger code.

A Increased security can also be achieved by that in particular when using several floors for each floor a separate trigger code is used. The trigger code may be a code generator unit, preferably is integrated in the computer unit, in particular by means of a Random generator generated.

Prefers the trigger code will be personalized before firing each bullet generated and handed over in particular before firing the bullet.

When using multiple floors, the remote control signals can be transmitted offset in time, in particular at intervals from the range of 50 microseconds to 300 microseconds, preferably 150 microseconds. This is particularly advantageous when there is a risk that due to a simultaneous activation of the carrier frequency unwanted modulation interference occur, in extreme cases lead to the non-triggering of all detonators. At a time interval of 150 μs, this results in local projectile deviations of 100 mm to 150 mm at common projectile speeds, but these can be neglected compared to other factors, such as the effective radius of the ammunition or the influence of the weather.

In An advantageous embodiment is in the transmission the remote control signals used the method of band spreading. Fundamental to this procedure is that the spectrum of the one to be transmitted Useful signal is changed such that on the one hand the Bandwidth increases many times, at the same time the signal amplitude is reduced by exactly this multiple. The band spread generated thus from the narrow-band remote control signal a broadbandigeres Remote control signal, so that the information contained in a larger Frequency range is distributed. This makes the remote control signals less susceptible to narrowband interference, which are initiated by the opponent, for example.

It Specifically, there are two methods such as this band spread Direct Sequence Spread Spectrum (DSSS) and Frequency Hopping Spread Spectrum (FHSS). Both techniques are spreading the original signal by selecting an individual, unique to the transmitter Mix the code with the signal.

The increased security results from the fact that, if a signal to be transmitted spreads so far and so that it is level-reduced, so that it is also below the noise limit comes to rest, a stranger party can not even recognize that just a remote control signal is sent, since they are only a noise signal measures. Only if the code signal with which the useful signal for band spreading multiplied, it is known, the useful signal from the "noise field" be extracted again. Because at multiplication of the splayed Signal, which may even be below the noise limit, with the associated Code signal, the bandwidth is restored to the original reduces and the amplitude straightens up again, leaving this again above the noise limit and thus recognized can. Furthermore, in the same frequency band different Channels (codes) are transmitted simultaneously, so when using several floors these ignited simultaneously can be. Thus, on the temporal displacement the signal transmission can be dispensed with.

The projectile can also have a second operating mode in addition to the first mode in which the direct remote release is performed. In the second mode of operation, the ignition control unit is designed to be programmable such that it can be _pre- temped to a predefined ignition time T. In particular, the ignition timing can be programmed before firing the projectile. Furthermore, the ignition time can be transferred together with the release code from the computer unit, in particular before firing. The ignition timing T _before can be dimensioned such that it lies before the predicted by the Feuerleitlösung time T _B , depending on a determined before the firing of the projectile for the projectile fire control solution in which the projectile hits the ground when ignited, for example the remote control signals could not be received or received properly.

In order to achieve a high effect of the projectile, the time T _{Ü of} the transmission of the remote control signals can be determined temporally after the firing of the projectile. In particular, thus, the further trajectory of the attack ammunition body can be considered. Furthermore, the movement of the projectile can also be taken into account when determining the optimum ignition timing. For this reason, it is advantageous if the velocity v _{M of} the projectile and the direction at a specific time T _M , be determined by means of at least one measuring device. In this case, they can be used to form the reference for the spatially fixed coordinate system of the ballistic calculations. By using a direct remote release, the determination of the optimum ignition timing can advantageously be delayed for as long as possible.

In one embodiment, the speed v _{M may be} the muzzle velocity v ₀ , wherein in this case the measuring device may in particular comprise a coil which is arranged in particular in the region of the mouth opening of the weapon barrel of the weapon. A coil for measuring the muzzle velocity of a projectile, for example, in the EP 1 482 311 A1 described in principle.

In another embodiment, the time T _{M represents} a time at which the projectile has already left the weapon. In this case, the measuring device may in particular comprise a radar device. In order not to unnecessarily lose time in this embodiment, the measuring device can be designed to be directed and be directed in the direction of the direction of firing already and at the time of firing the projectile. This can be achieved for example by a coupling between the weapon and the measuring device.

The determined speed v _M and the direction at the time T _M can be taken into account in the determination of the time T _{Z of} the ignition of the projectile. It can thus be the actual, Time-dependent trajectory of the projectile are determined more accurately, so that a higher probability of successful control is achieved. Therefore, a measuring device with a high accuracy should be used. In particular, a measuring device is used whose standard deviation in the velocity determination is less than 0.5 m / s. Furthermore, the signal propagation times should be kept short, preferably real-time capable components should be used.

The apparatus and method can be effectively used for protection against flying attack ammunition. Here, the attack ammunition is first located by means of at least one locating device. After locating the attack ammunition by the locating device, the trajectory of the attack ammunition body can be determined. The faster and more accurately the trajectory is determined, the more likely is successful combat of the assault ammunition. The locating device, which comprises at least one sensor (eg radar, active and / or passive optoelectronic), should provide coordinates and / or speed of the assault ammunition body at a sufficient number of times. Furthermore, in particular by means of a fire control computer, which can be arranged within a fire control station, a first Feuerleitlösung for firing the projectile with fragmentation, in particular an explosive projectile, determined. The projectile is then fired by means of a particularly large-caliber weapon, in particular a weapon with a caliber of at least 76 mm, preferably of 120 mm or 155 mm. Such large-caliber weapons have a long range and a high achievable muzzle velocity of the projectiles, so that even in the long-range combat the assault ammunition body can be achieved. The use of large calibers is also advantageous over the use of small calibers, since in small caliber splinters derive their energy primarily from the web speed, since due to the volume usually only one Zerlegerla training can be installed in a small caliber projectile. However, as the distance increases, the velocity and energy of the projectile decreases sharply. In the case of large calibers, on the other hand, an HE charge can be used, from which the splinters primarily draw their energy, so that this energy is independent of the range. Thus, it can be achieved that even in the protection of larger objects, the projectiles in the near and far, and against the hardest attacking object are equally effective. The remote control signals are then transmitted at a time T _Ü to the projectile in which the attack ammunition is in the effective range of the splitter-acting projectile.

The determination of the time T _Ü can be such that the time is determined in which there is a high, preferably the highest probability of successful combat, and in particular from the product of the hit probability, which indicates whether a splinter hits the attack ammunition, with the probability of destruction, indicating whether this splinter is capable of destroying the shell of the assault ammunition body. This control probability is thus dependent on various parameters, such as a) measurement inaccuracies of the measuring device, in particular in the determination of time, speed, azimuth, elevation and / or distance; b) measurement inaccuracies of the locating device, in particular in the determination of time, speed, azimuth, elevation and / or distance; c) Type of assault ammunition ( 4 ), in particular its hardness; d) type of bullet, in particular its properties such as splinter matrix, splitter cone build-up time, inaccuracies of the tempier time; e) Shot development time of the projectile and f) Ballistic dispersion. The more parameters are taken into account in the determination of the time T _Ü , the better the prediction.

Of the precise ignition timing is essential, especially in the long-range for the effectiveness of the fight, there already small deviations due to the high speeds and long distances to large differences between the predicted and can lead to the actual Zündort.

The first determined Feuerleitlösung, after which the projectile is fired, is preferably dimensioned such that the Compensation of tolerances of the sensors used Locating and measuring device and the used, or effectors containing weapon and projectile determined by the after firing Ignition timing is possible.

Advantageous it is, with several floors at the same time the attack ammunition to fight. These can be preferred at the same time in at a point where also the assault ammo body is and then remotely triggered at approximately the same time become.

The Programming the detonator for direct remote release usually requires, as in this case the ignition not a priori is known that the ignition capacitor already is charged after the end of the Vorrohrsicherheit, what else in a pure Timing function takes place approx. 2 s before the end of the term.

So that as little time between Zielor can be envisaged to make programming permanent. The projectile does not lose its programming in the mode of direct remote release time-dependent, so that such a projectile already programmed in the tube can also wait days for its use.

In the operating mode as Zeitzünder the bullet can its Lose programming within a given time window, in particular at the earliest after 20 minutes and at the latest after 60 minutes to get through the endangerment of your own troop to reduce an outdated fire command.

Around a high accuracy in the determination of trajectory parameters of the Attacking ammunition with little effort, can after the first detection of the assault ammunition by the locating device sends the locating data to a second locating device, in particular, a destination follower radar device which are the measurement of the trajectory determination necessary sizes. First Locating device can be used here a Rundsuchradar.

A possible embodiment of the invention will be described with reference to 1 explained. It shows:

1 a device for protection against assault ammunition in a schematic representation.

The 1 shows a device for protection against attack ammunition in a schematic representation. She has a gun 2 , the projectiles 3 can fire with fragmentation, a first locating device 12 , a second locating device 5 , a measuring device 10 , a signal transmission unit 7 and a fire control computer 6 on. The weapon 2 , the locating device 5 , the measuring device 10 and the signal transmission unit 7 are via data lines 11 with the fire control computer 6 connected. For optimum control are the locating device 5 and the weapon 2 spatially close to dislocate. The projectile 3 includes an ignition control unit 9 , a signal receiving unit 8th , a detonator 13 and an explosive charge 14 ,

• I. Ortung des Angriffsmunitionskörpers 4 mit einer ersten Ortungseinrichtung 12, insbesondere einem Rundsuchradargerät;
• II. Übergabe der Zieldaten an eine zweite Ortungseinrichtung 5, insbesondere ein Zielfolgeradargerät, und Zielverfolgung;
• III. Berechnung der Feuerleitlösung durch den Feuerleitrechner 6;
• IV. Richten der Waffe 2, hier eine Panzerhaubitze (155 mm);
• V. Abfeuern des Geschosses 3, um eine Bekämpfung in der gewünschten Entfernung durchzuführen;
• VI. Messung der Geschossgeschwindigkeit v_M und Übermittlung der Daten an den Feuerleitrechner 6;
• VII. Berechnung einer korrigierten Feuerleitlösung und Bestimmung des Zündzeitpunkts;
• VIII. Übertragung der Fernsteuersignale von der Signalsendeeinheit 7 zur Signalempfangseinheit 8 und somit direkte Fernauslösung des Zünders 13 über die Zündsteuereinheit 9 zum Zündzeitpunkt, der somit dem Übertragungszeitpunkt T_Ü der Fernsteuersignale entspricht;
• IX. Zündung der Sprengladung 14, Ausbildung des Splitterkegels

The control procedure is as follows:

• I. Location of the assault ammunition 4 with a first locating device 12 , in particular a Rundsuchradargerät;
• II. Transfer of the target data to a second location facility 5 , in particular a destination follower radar device, and target tracking;
• III. Calculation of the fire control solution by the fire control computer 6 ;
• IV. Judging the weapon 2 , here a tank howitzer (155 mm);
• V. Firing the projectile 3 to perform control at the desired distance;
• VI. Measurement of the projectile velocity v _M and transmission of the data to the fire control computer 6 ;
• VII. Calculation of a corrected fire-control solution and determination of the ignition timing;
• VIII. Transmission of remote control signals from the signal transmission unit 7 to the signal receiving unit 8th and thus direct remote release of the detonator 13 via the ignition control unit 9 at the ignition timing, thus corresponding to the transmission time T _{Ü of} the remote control signals;
• IX. Ignition of the explosive charge 14 , Formation of the fragment cone

To VIII .:
The remote control signals include as a trigger code a codeword with a length of 52 bits, which is evaluated by the ignition control unit to determine the correct reception of the remote control signals. The trigger code is modulated in the transmission of the remote control signals to a carrier frequency of 520 kHz, thus the entire code can be sent within 100 microseconds and thus the ignition timing practically coincides with the transmission time T _Ü .

The codeword is generated by a random generator in the fire control computer 6 generated, so every bullet 3 individually assigned a codeword. The codeword becomes the bullet before firing 3 preferably passed through inductive programming.

When using several floors 3 are used, if no band spread is used, the remote control signals transmitted in a staggered manner, namely at intervals of 150 microseconds.

Everyone Igniter compares the code received by radio with his while programming stored code and triggers if and only if the two codes match. vote the codes do not match, the detonator waits within its programmed self-destruct time on the transmission the correct code. If this is not received, triggers the detonator after the programmed Selbstzerlegezeit out.

at incorrect reception of the remote control signals (for example, in faulty or incomplete code) can be a feedback to the fire station.

As an advantageous safety aspect is also provided that the projectile 3 before the firing is _pre- tempered _before a time T _{, which} lies ahead of the predicted by the determined before firing Feuerleitlösung time T _B , in which the projectile hits the ground when ignited. Thus, it is ensured that, for example, in the case where the ignition timing or the remote control signals have not been transmitted correctly, the projectile 3 ignites before striking the ground, so that no persons or facilities on the ground come to harm. However, so that the ignition is not too early, especially not before the time in which the signals from the projectile 3 be received, it may be provided that the time T is _{ahead of} time after the time T _A , by the predicted by the determined before firing Feuerleitlösung ignition time T _{Z of} the projectile 3 is determined.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 4426014 B4 [0003]
• - DE 10024320 C2 [0003]
• EP 1518087 B1 [0003]
• - DE 60012654 T2 [0003]
• - DE 10025105 B4 [0003]
• - DE 10151897 A1 [0003]
• EP 1742010 A1 [0010]
• DE 102005024179 A1 [0011]
• - EP 1482311 A1 [0027]

Claims (21)

Method for remote triggering of at least one weapon ( 2 ) fired projectile ( 3 ) with a detonator ( 13 ) by a computer unit ( 6 ), in particular a fire control computer, to which a signal transmission unit ( 7 ), in particular a radio unit, is connected, a. whereby by initiation by the computer unit ( 6 ) the signal transmission unit ( 7 ) Sends remote control signals, b. wherein a signal receiving unit ( 8th ), in particular a radio unit, of the projectile ( 3 receiving the remote control signals, and c. one to the signal receiving unit ( 8th ) connected ignition control unit ( 9 ) immediately after the correct reception of the remote control signals the ignition by the fuze ( 13 ). A method according to claim 1, characterized in that the remote control signals include a trigger code and that the ignition control unit ( 9 ) determines the correct reception of the remote control signals by evaluating the release code. Method according to claim 2, characterized in that that the trigger code in the transmission of the remote control signals is modulated onto a carrier frequency. Method according to claim 2 or 3, characterized that the trigger code at least one code word, in particular with a length of 52 bits. Method according to one of claims 2 to 4, characterized in that when using several floors ( 3 ) for each floor ( 3 ) a separate trigger code is used. Method according to one of claims 2 to 5, characterized in that the trigger code of a Code generator unit, in particular by means of a random number generator is generated. Method according to one of claims 2 to 6, characterized in that the triggering code before firing individually for each floor ( 3 ) is generated. Method according to one of claims 2 to 7, characterized in that the triggering code before firing the projectile ( 3 ). Method according to one of the preceding claims, characterized in that when using several floors ( 3 ) The remote control signals are transmitted offset in time, in particular at intervals from the range of 50 microseconds to 300 microseconds, preferably 150 microseconds. Method according to one of the preceding claims, characterized in that in the transmission of the remote control signals the method of band spreading is used. Method according to one of the preceding claims, characterized in that the igniter ( 13 ) has a firing capacitor, which is charged already after the end of the Vorrohrsicherheit. Method according to one of the preceding claims, characterized in that the ignition control unit ( 13 ) _is programmed with a predetermined ignition timing T _before . A method according to claim 12, characterized in that the ignition timing T _before time before the firing of the projectile ( 3 ) is programmed. A method according to claim 13, characterized in that the ignition timing T _ago together with the release code in particular from the computer unit ( 6 ). Method according to one of claims 12 to 14, characterized in that the ignition timing T _before depending on one before the firing of the projectile ( 3 ), for the projectile ( 3 ) is dimensioned such that it lies in front of the predicted by the Feuerleitlösung time T _B , in which the projectile ( 3 ) hits the ground when ignited. Method according to one of the preceding claims, characterized in that the time T _{Ü of} the transmission of the remote control signals in time after the firing of the projectile ( 3 ) is determined. A method according to claim 16, characterized in that for determining the time T _Ü the speed v _{M of} the projectile ( 3 ) at a certain time T _M , in particular when leaving the weapon ( 2 ), by means of at least one measuring device ( 10 ) is determined. A method according to claim 17, characterized in that the speed v _{M is} the muzzle velocity vo and that the measuring device ( 10 ) comprises in particular a coil, which is arranged in particular in the region of the mouth opening of the weapon barrel. A method according to claim 17, characterized in that the time T _{M represents} a time at which the projectile ( 3 ) the weapon ( 2 ) and that the measuring device ( 10 ) comprises in particular a radar device. Device for the remote release of a projectile ( 3 ) with a detonator ( 13 ) by a computer unit ( 6 ), in particular a fire control computer, to which a signal transmission unit ( 7 ), in particular a radio unit, is connected, a. whereby the projectile ( 3 ) a remotely controllable by remote control signals ignition control unit ( 9 ), b. whereby the projectile ( 3 ) a signal receiving unit ( 8th ), in particular a radio unit, for receiving the signals from the signal transmission unit ( 7 ) has transmitted remote control signals, and c. wherein the ignition control unit ( 9 ) is configured such that it initiates the ignition immediately after the correct reception of the remote control signals. Use of the device according to claim 20 for protection against flying attack ammunition ( 4 ), where a. the assault ammo ( 4 ) by means of at least one locating device ( 5 . 12 ) is located, b. the trajectory of the assault ammunition ( 4 ), c. a Feuerleitlösung for firing the projectile ( 3 ) is determined with fragmentation, d. by means of a preferably large-caliber weapon ( 2 ), in particular a weapon ( 2 ) with a caliber of at least 76 mm, the projectile ( 3 ) is fired, and e. the remote control signals at a time T _Ü to the floor ( 3 ), in which the attacking body ( 4 ) in the effective range of the splitter-acting projectile ( 3 ) is located.