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As illustrated in literature, ballistics is a branch of theoretical mechanics, which studies the construction and working principles of firearms and ammunition, their effects, as well as the motions of projectiles and bullets 1 . Criminalistics identification, as part of judiciary identification represents an activity aimed at finding common traits of different objects, objectives, phenomena and beings, but more importantly, traits that differentiate each of them from similar ones 2-4 . In judicial ballistics, in the case of rifled firearms it is relatively simple for experts to identify the used weapon from traces left on the projectile, as the rifling of the barrel leaves imprints on the bullet, which remain approximately identical even after the respective weapon is fired 100 times with the same barrel. However, in the case of smoothbore firearms, their identification becomes much more complicated. As the firing cap suffers alterations from being hit by the firing pin, determination of the force generated during impact creates the premises for determining the type of firearm used to shoot the respective cartridge. The present paper proposes a simple impact model that can be used to evaluate the force generated by the firing pin during its impact with the firing cap. The present research clearly showed that each rifle, by the combination of the three investigated parameters (impact force maximum value, its variation diagram, and impact time) leave a unique trace. Application of such a method in ballistics can create the perspectives for formulating clear conclusions that eliminate possible judicial errors in this field.

High frame-rate imaging is a valuable tool for non-destructive evaluation (NDE) as well as for ballistic impact studies (terminal ballistics), in-flight projectile imaging, studies of exploding ordnance and characterization of other high-speed phenomena. Current imaging systems exist for these studies, however, none have the ability to do in-barrel characterization (in-bore ballistics) to image kinetics of the moving projectile BEFORE it exits the barrel. The system uses an intensified high-speed CMOS camera coupled to a specially designed scintillator to serve as the X-ray detector. The X-ray source is a sequentially fired portable pulsed unit synchronized with the detector integration window and is able to acquire 3,600 frames per second (fps) with mega-pixel spatial resolution and up to 500,000 fps with reduced pixel resolution. This paper will discuss our results imaging .30 caliber bullets traveling at ~1,000 m/s while still in the barrel. Information on bullet deformation, pitch, yaw and integrity are the main goals of this experimentation. Planned future upgrades for imaging large caliber projectiles will also be discussed.

Sensors capable of measuring the quasi-electrostatic field of traveling projectiles have been developed to detect the passage of a bullet in flight. These sensors provide an alternative to existing optical chronograph technologies, which are sensitive to variations in environmental lighting, and magnetic chronographs, which require close proximity to the bullet’s path. In contrast, electric field sensors are insensitive to lighting changes and prior testing has demonstrated the ability to reliably detect bullets at distances of at least three meters. A linear array of these sensors has been used to measure the time of flight between the sensors, which with the known distance between the sensors can be used to calculate the projectile’s velocity. These velocity measurements are compared to established chronograph technology as a measurement validation. By extending this array of sensors along the projected path of the projectile, a profile of the projectile’s position and velocity through flight can be calculated. This expected utility of this data is in refining the calculations that are performed to determine a ballistic solution, particularly in long range engagements, where there has been limited availability of accurate projectile velocity measurements. This robust sensor array that can easily be deployed represents an inexpensive way to experimentally investigate numerous phenomena related to ballistics modeling.

The progress on a laser- and stereo-camera-based trajectory measurement system that we already proposed and described in recent publications is given. The system design was extended from one to two more powerful, DSP-controllable LASER systems. Experimental results of the extended system using different projectile-/weapon combinations will be shown and discussed. Automatic processing of acquired images using common 3DIP techniques was realized. Processing steps to extract trajectory segments from images as representative for the current application will be presented. Used algorithms for backward-calculation of the projectile trajectory will be shown. Verification of produced results is done against simulated trajectories, once in terms of detection robustness and once in terms of detection accuracy. Fields of use for the current system are within the ballistic domain. The first purpose is for trajectory measurement of small and middle caliber projectiles on a shooting range. Extension to big caliber projectiles as well as an application for sniper detection is imaginable, but would require further work. Beside classical RADAR, acoustic and optical projectile detection methods, the current system represents a further projectile location method under the new class of electro-optical methods that have been evolved in recent decades and that uses 3D imaging acquisition and processing techniques.

This paper presents an interacting multiple model (IMM) based procedure to estimate the state of thrusting ballistic projectiles in the atmosphere for the purpose of impact point prediction (IPP). The modes of the IMM estimator are for the thrusting and the ballistic phases and different extended Kalman filters (EKF) are used as the mode-matched filters with different dimension states. The IPP is achieved by using the IMM-predicted most probable mode at the mid-point of the trajectory.

Military camps in out-of-area missions are permanently threatened by rockets, artillery projectiles, and mortar grenades (RAM) launched by terrorists. A good portion of these attacks are undertaken by mortars due to their specific advantages for the warfare of irregular forces and their worldwide distribution. The military installations can be protected by counter-RAM systems consisting of several artillery weapons, radar and electro-optical sensors, C 2 and fire control computers. A system analysis has shown that the precision of the sensors is vital for defending the camp with low ammunition consumptions. Furthermore, the type of ammunition is also of great impact: 35 mm Ahead ammunition is hardly suited for this application due to its small hit density and low kinetic energy of the sub-projectiles, especially in the case of mortar grenades. Therefore, 155 mm high-explosive (HE) ammunition is investigated using experimentally determined fragment data. Russian mortar projectiles are considered as worst-case RAM targets and their ballistics are mathematically modeled by an air drag function that is also used for computing firing tables. Due to uncertainties of the target positions that are given by an elliptic cylinder for specific sensor parameters, simulations are conducted in order to determine the ammunition consumption. Penetration and detonation criteria for the terminal impact are also considered and the resulting thresholds are displayed in a 3D fragment map. The results show that HE ammunition is superior to low-caliber ammunition because of their high numbers of effective fragments reducing the number of rounds significantly from hundreds to less than ten.

This paper presents a multiple model procedure to estimate the state of a ballistic object in the atmosphere and identify it using radar measurements. The measurements are taken during the first part of its trajectory and the final state estimate is then predicted to its impact point on earth. This paper uses, for each model, a different extended Kalman filter for state estimation and then uses the model likelihoods to identify the projectile. Simulations are carried out on three mortar trajectories using 7-state models. It is shown from simulations carried out on several ballistic trajectories that the impact point is predicted to a high degree of accuracy and with a consistent covariance and that the projectile can be identified with a high probability.

To recognize the targets state in a battlefield after shots, it's possible to send a video sensor with the same ballistics than real ammunitions. This article describes the modeling of observation ammunition using simulation workshop CHORALE and AMOCO. Before real trials on a battlefield and to define the final features of an embedded video sensor, it is necessary to modeling each part of the behavior of the ammunition. The goal of this simulation is to know how the ammunition with its movements as the rotation, pitch, yaw can see the proving ground and what values of parameters it is possible to set into the embedded sensor. To perform the simulation, we need of a ballistics model taking into account the geometric form of the projectile. This ammunition flights over a battlefield so we need a realistic 3D scene model taking into account the atmospheric conditions, real target, geometric target and all existing things on a real proving ground as building, forest and so on. The frame seen by the sensor is modified by its transfer function. The video sensor model takes into account lot of functional parameters as Optic, Detector and electronic function. An algorithm takes place at the incoming step in the sensor model and takes into account the rotation during the integration time. Each model calculates independently.

Air Force Research Laboratory and MetroLaser, Inc. researchers have completed the initial development and transition to operational use of portable field holography systems. This paper documents the first fully operational use of a novel and unique experimental capability for remote field holography. In this paper we document the field trials and initial experiments that were performed with the Remote Holographic Interferometry System (RHIS) at the Munitions Directorate, Air Force Research Laboratory Site at Eglin, AFB, Florida. These experiments were performed to assess the effectiveness of remote pulsed laser holography combined with high-speed videography to document the formation and propagation of plumes of materials created by impact of high-speed projectiles. This paper details the development of the experimental procedures and initial results of this new tool.

A spent cartridge case exhibits characteristic markings (firearm fingerprint) that can be used to identify the type, and possibly make, of weapon in which the cartridge was fired. This paper details research into the use of discriminant analysis for the purpose of matching spent cartridge cases to specific make and model of firearms. A fired projectile can also be analyzed by measuring the class characteristics such as land mark, groove, mar, and twist ratio. A personal computer (PC) based prototype software application called FireBall will also be described in detail.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Frankford Arsenal was a pioneer in the development and application of flash radiography of ballistic phenomena. Frankford Arsenal first began using the Westinghouse Micronex flash X-ray system in 1941, and converted to Field Emission Corporation (now Hewlett-Packard) flash X-ray equipment in the early 1960's. When Frankford Arsenal closed in 1977, its missions and equipment were transferred to U.S. Army Armament Research and Development Command. The flash X-ray studies performed at Frankford Arsenal are now being continued at the ARRADCOM Test Site, Fort Dix, New Jersey as well as at ARRADCOM Headquarters, Dover, New Jersey. These studies are concerned with investigations of small caliber ammunition and weapons, and reduced scale models of large caliber projectiles. The important feature of flash X-rays in ballistics research and development is that high speed radiographs provide qualitative and quantitative information which frequently cannot be obtained by any other means or which can be obtained more easily and inexpensively by this technique. This paper describes some of the experimental applications of high speed radiography in obtaining data on various ballistic phenomena such as the determination of projectile penetration of armor plate, and particle size and orientation after penetration.© (1983) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

COMPARISON OF HIGH SPEED MOVIE AND FLASH X -RAYMEASUREMENT OF THE TRANSLATIONAL ANDROTATIONAL MOTIONS OF PROJECTILESPENETRATING GELATINEUGENE T. ROECKERUS Army Ballistic Research LaboratoryTerminal Ballistics DivisionAberdeen Proving Ground, MD 21005, U.S.A.Projectiles penetrating a gelatin block were simultaneously mea-sured by a high speed movie camera, Dynafax, and by a sequential,orthogonal, flash x -ray system. The eight orthogonal views of thex -ray system provided position and orientation of the projectiles vs.time From onset of tumble in the gelatin, owing to gyroscopic in-stability, the growth of yaw was the same for each round in a re-plicated set. This phenomenon provided a legitimate procedure forpooling the x -ray data, giving well determined curves of velocitydecay and yaw growth. The movie camera observed the progress of thecavity formed by the projectile. The resulting velocity decay of thecavity tip was compared to that of the projectile as measured by thex -ray technique.

This paper covers the design and application of a state-of-the-art optoelectronic instrumentation system called the Projectile Follower System (PFS). This system is designed to produce high speed motion picture photographic or video records for investigating dynamic ballistic phenomena of ammunition during external flight. It is designed to be used for developing and testing U.S. Army ammunition and especially for high velocity projectiles fired from direct fire weapons such as tank guns. The fundamental operational concept is that the vertical axis of a rotatable mirror is driven synchronously with the motion of the projectile, and thus the projectile is maintained within the field of view of stationary motion picture or video cameras aimed at the mirror. The PFS incorporates microprocegsor and computer control to achieve angular accelerations of the mirror of up to 2,100 rad/s . The mirror is manufactured from beryllium using a honeycomb construction and has a 300 x 500 mm optical surface. It can also be used to provide auxiliary illumination by reflecting a beam generated from a stationary light source onto the moving projectile. Compared to a conventional high speed motion picture camera system, the PFS covers a far greater portion of the projectile's flight from a single camera station with a relatively larger photographic image size. The resulting photographs display a considerable reduction in blur. This paper describes the PFS optoelectronic engineering system design and application. Included are the mirror and its drive, control and drive electronics, projectile synchronization, muzzle velocity correction, projectile illumination, and cameras and related optics. The range installation, data recording methods, and future expansion capability are also discussed.