Abstract: A method is provided for classifying an object, in particular in the surroundings of a motor vehicle, using an ultrasonic sensor system, the ultrasonic sensor system including a plurality of spatially distributed ultrasonic sensors. A plurality of measurements are carried out continuously during a measurement, an ultrasonic signal being emitted by one of the ultrasonic sensors, a signal being received by at least one of the ultrasonic sensors which includes a plurality of reflected echo signals, so-called multiple echoes, and the received echo signals being associated with an object. A plurality of features may be determined from the received echo signals. The object is classified as a function of a combination of at least two of these features, in particular as a pedestrian.

Abstract: Acoustic signals from an acoustic event are captured via sensing nodes of sensor group(s) that comprise a group of sensing nodes at a location comprising spatial boundaries. Each of the sensing nodes comprise a sensor area. Each of the sensor group(s) is based on: range limits of each of the sensing nodes; shared sensing areas of the sensing nodes; and intersections between the sensor area for each of the sensing nodes and the spatial boundaries. Solutions(s) are generated by processing the acoustic signals. The solution(s) indicate the location of the acoustic event. A strength of solution compliance value for at least one of the solution(s) is determined. A refined solution is generated employing: sensor contributions of sensing nodes; and the strength of solution compliance value with the spatial boundaries and at least one of the solution(s). A report is created comprising the location of the acoustic event.

Abstract: Acoustic signals from an acoustic event are captured via sensing nodes of sensor group(s) that comprise a group of sensing nodes at a location comprising spatial boundaries. Each of the sensing nodes comprise a sensor area. Each of the sensor group(s) is based on: range limits of each of the sensing nodes; shared sensing areas of the sensing nodes; and intersections between the sensor area for each of the sensing nodes and the spatial boundaries. Solutions(s) are generated by processing the acoustic signals. The solution(s) indicate the location of the acoustic event. A strength of solution compliance value for at least one of the solution(s) is determined. A refined solution is generated employing: sensor contributions of sensing nodes; and the strength of solution compliance value with the spatial boundaries and at least one of the solution(s). A report is created comprising the location of the acoustic event.

Abstract: A trajectory estimation device that includes a waveform generation unit that generates, by using signals based on waves detected by at least three sensors, peak waveforms consisting of time series data of peak frequencies of the signals, a parameter estimation unit that estimates, from the peak waveforms relating to the waves detected by the at least three sensors, a trajectory parameter relating to a trajectory of a moving body having a wave source of the waves, and a trajectory estimation unit that estimates, for all combinations of two of the peak waveforms selected from among combinations of at least three of the peak waveforms, a wave source direction candidate for each of the waves by using the trajectory parameter, and estimate, as a trajectory of the moving body, overlapping trajectory candidates from among trajectory candidates estimated based on the wave source direction candidates.

Abstract: The disclosed system and method for smart detection of an armament projectile can mitigate the detection of its radar by counter-radar systems. Particularly, the system may include an array of acoustic sensors for sensing one or more volleys associated with an armament projectile. An intelligent filtering module, coupled to the array of acoustic sensors, may select a volley based upon a learning algorithm, which can be applied to a target profile of historical system data logs. Based upon sensed parameters of the volley, the intelligent filtering module can calculate a radiation duration and a search fan width for radar transmission. Specifically, a controller, within the intelligent filtering module, may couple to actuate the radar at the calculated search fan width for the calculated radiation duration. In some embodiments, the intelligent filtering module can selectively actuate one radar based upon highest expanded detection probability relative to location and status.

Abstract: A method, system, and computer-readable media for analyzing blast exposure data in which one or more spurious data features are identified, flagged, and removed from a set of pressure data received from a blast sensor. Pressure data sets are grouped based on waveform features to determine one or more incident overpressure parameters associated with a blast exposure event.

Abstract: Disclosed is a method for controlling an engine control unit which includes at least two microprocessor cores, including steps of executing a parent subtask and at least one child subtask. The method includes the following steps: —determining the number of executables which remain to be executed in the last child subtask of the first period when the parent subtask of the second period starts; and—determining the number of executables already executed in the parent subtask of the second period when the last child subtask of the first period finishes.

Abstract: A smart target co-witnessing hit attribution system includes a network, a projectile-firing device that includes a projectile repository and an infrared emitter, a smart target that includes a piezoelectric sensor, an infrared sensor, and control circuitry, and an extended-reality gaming application. After confirming a successful hit on the smart target, the application receives target state data and updates gaming metric data to attribute a successful impact on the smart target by the projectile-firing device.

Abstract: A method providing an estimation of a shooting range with high accuracy by a miss distance estimation and a weapon caliber classification following detection of shooting of firearms with supersonic bullets, and by using novel equations constructed from field shooting data for each caliber in order to ensure a security of a patrol station, a border, troops, a society, a vehicle and a convoy is provided.

Abstract: A system and method of detecting and analyzing a threat in a confined environment is disclosed. An audio board detects and analyzes audio signals. A RF board transmits the signals for emergency response. A battery provides power to the audio board and the RF board. The audio board includes a microcontroller with at least one band-pass filter for distinguishing between a threat and a non-threat event and for measuring or counting pulses if the event is a threat.

Abstract: An aircraft including: a penetration member that penetrates an airframe between an inside and an outside via an opening provided in the airframe; a seal that seals a gap set between an opening formation member forming the opening and the penetration member; and a retainer that presses the seal against the penetration member and the opening formation member, wherein each of the penetration member and the opening formation member includes a receiving section that receives the seal, both of the receiving sections are arranged along a direction connecting one side and the other side of the gap with the gap therebetween, and the seal is fixed to only one of the receiving section of the penetration member and the receiving section of the opening formation member.

Abstract: A system for modifying a shock wave formed in a fluid by a body to modify effects of the shock wave on information transferred to or from the body. The system includes an element for heating fluid along a path to form a volume of heated fluid expanding outwardly from the path, the path extending from the body and through the shock wave; an element for transferring the information to or from the body; and an element for timing the transferring of the information relative to the heating of the fluid along the path to modify certain effects of the shock wave on the information.

Abstract: Systems and method of processing information regarding weapon fire are set forth herein. In one exemplary implementation, a method of processing information regarding weapon fire, such as determining weapon fire location using projectile shockwave and muzzle blast time(s) of arrival data is disclosed.

Abstract: Systems and methods for estimating projectile trajectory and projectile source location are provided. A method for estimating location information associated with a supersonic projectile propelled from a source includes recording sound at a first location using a single microphone during travel of the supersonic projectile to produce an acoustic recording. The method further includes estimating a miss distance between the first location and a trajectory of the projectile based on the shockwave length. Locating a projectile source includes concurrently recording sound at multiple locations and generating data sets associated with the locations, each of the plurality of data sets including a miss distance, a range, a time of arrival of a muzzle blast from the source, and a time of arrival of a shockwave produced by the projectile. Additionally, the method includes calculating an approximate location of the source at each of the locations based on the data sets.

Abstract: A computer implemented method for discriminating between launch and impact events using acoustic sensors.

Abstract: The systems and methods described herein relate to an airborne shooter detection system having a plurality of sensors coupled to the body of an aircraft such as a helicopter. The system includes at least five sensors configured and arranged to disambiguate the location of a shooter. By measuring the arrival times of the shockwaves of projectiles at each of the sensors and determining the differences in the arrival times among sensors, the systems and methods may determine the location of one or more sources of the projectiles. A distance of at least ten meters separates two or more of the sensors. Such a separation is advantageous because it allows the system to disambiguate multiple shooters by resolving the curvature of the shockwave.

Abstract: Systems and methods are disclosed for processing information associated with monitoring persons/devices and weapon fire location information. In one exemplary implementation, a weapon fire location system is used to characterize and locate impulsive events and these locations are correlated with the positions of monitoring persons or devices, such as monitoring anklets placed on offenders or other persons of interest. Further, various information can be plotted on map, display, or for other graphical output to assist in the process of handling a weapon fire event. For example, when a monitoring device, whose position can be provided by GPS or alternate methods is found nearby a gunshot location, then associated graphical information can be presented on the output of the weapon fire location system or an associated display used by those monitoring the offenders.

Abstract: Systems and methods are disclosed for locating a weapon fire incident such as an acoustic transient from a gunshot, explosion, weapons launch, etc. In one exemplary implementation, there is provided a method of locating the incident from a combination of propagation phenomena including a discharge time of the weapon fire incident. Moreover, the method may include obtaining a first propagation parameter of the incident from one or more first sensors, obtaining the discharge time from another sensor, and processing the data to determine a location using a common time basis among sensor measurements. According to further exemplary implementations, the discharge time may include a transient event that has a different propagation velocity than that of sound in the atmosphere.

Abstract: A survey method giving improvements in weapons fire location systems is disclosed. In an urban system with a distributed array in the midst of many buildings that block signal paths or create echoes, methods are provided to measure signal propagation. A survey or tour of the covered region uses a moving signal source to probe propagation inside the region. Survey results may indicate where more or fewer sensors are needed. Survey results plus current measured noise gives prediction of instantaneous system sensitivity. In addition, multipath propagation may be used to determine a location even when only one or two sensors detect the signal. In such exemplary cases, triangulation may be replaced or augmented by pattern recognition. Further, signals of the survey need not be acoustic impulses such as gunfire, but may be RF signals, or coded continuous signals so that gunfire-like sounds would not disturb citizens in the area.

Abstract: Disclosed are systems and methods that can be used to detect shooters. The systems and methods described herein use arrival times of a shockwave, produced by a shot, at a plurality of sensors to assign weights to each of the plurality of sensors, and determine a shot trajectory based on the assigned weights.

Abstract: Disclosed are systems and methods that can be used to detect shooters. The systems and methods described herein use arrival times of a shockwave, produced by a shot, at a plurality of sensors to assign weights to each of the plurality of sensors, and determine a shot trajectory based on the assigned weights.

Abstract: Systems and methods are disclosed for processing weapon fire information such as gunfire. In one exemplary implementation, there is provided a method of processing gunshot information to determine source location information involving echo/reflection processing features. Moreover, the method may include processing gunshot information received from a source at a sensor having a reflecting surface at a given distance, processing direct arrival time and echo arrival time information, and determining source location information as a function of a virtual sensor calculated behind the surface.

Abstract: User-wearable sensor arrays for use with projectile-detection systems, and methods of detecting a projectile with user-wearable sensor arrays.

Abstract: A system and method is provided for estimating a trajectory of an incoming bullet based on the acoustics of the shock wave created as the bullet travels through the air. A first auditory signal representing a direct sound from the shock wave is recorded and its azimuthal direction is determined. Based on this azimuthal direction and other assumptions two possible bullet directions that can cause that shock wave are estimated. A second auditory signal representing a reflection of the shock wave as it travels through the air also is recorded and its azimuthal direction determined. The azimuthal direction of the ground reflection will lie between the azimuthal direction of the first auditory signal and the more correct of the two estimated trajectories, and thus can resolve the ambiguity in the estimated direction of the bullet source.

Abstract: Systems and methods are provided for locating threats to an aircraft that are located on the ground. Associated bearings are determined from an aircraft for each of a plurality of detected shots from a threat at ground level. A plurality of pairs of bearings are selected, and a weight value is calculated for each selected pair of bearings. An estimated position for the threat is determined from each selected pair of bearings. An improved estimation of the position for the threat is calculated as a weighted combination of the estimated positions.

Abstract: A system and method for implementing non-lethal chemical warfare against rampage shooters. A sound detection module detects a sound of a gunshot from at least one of a collection of sensors within a building. A sound location module determines a location of the gunshot by analyzing the sound. At least one emitter releases non-lethal chemical countermeasures from at least one at the location of the gunshot.

Abstract: Systems and methods are disclosed for processing information associated with weapon fire. In one exemplary embodiment, there is provided a method of processing information associated with weapon fire, including identifying a weapon fire incident, determining positional information regarding a source location of the weapon fire, and processing positional information regarding a device within a particular proximity of the source location of the weapon fire. Moreover, exemplary methods may include providing information for displaying the positional information of the source location of the weapon fire and the device together on a display. Other exemplary embodiments may include performing processing that provides one or more of source location of the weapon fire, device location information and/or other information related to the device for various uses.

Abstract: Systems and methods for locating the shooter of supersonic projectiles are described. The system uses at least five, preferably seven, spaced acoustic sensors. Sensor signals are detected for shockwaves and muzzle blast, wherein muzzle blast detection can be either incomplete coming from less than 4 sensor channels, or inconclusive due to lack of signal strength. Shooter range can be determined by an iterative computation and/or a genetic algorithm by minimizing a cost function that includes timing information from both shockwave and muzzle signal channels. Disambiguation is significantly improved over shockwave-only measurements.

Abstract: A system for locating and identifying an acoustic event such as gunfire. The inventive system employs a plurality of man wearable acoustic sensors for detecting gunfire, each acoustic sensor having a display associated therewith for displaying information concerning the acoustic event to a user. In preferred embodiments, the sensor includes a microphone for/receiving acoustic information; an A/D converter; a processor for processing the digitized signal to detect a gunshot and determine a time of arrival; a GPS receiver for determining the position of the acoustic sensor; and a network interface for bidirectional communication with a system server. Preferably the display comprises an LCD; and an electronically readable compass. When the display and acoustic sensor are in separate housings, the acoustic sensor includes a transmitter and the display includes a receiver for transferring the gunshot information.

Abstract: A system and method for detecting, identifying, and fixing the location of the source of an acoustic event. The inventive system includes: a plurality of sensors dispersed at somewhat regular intervals throughout a monitored area; a communication network adapted to deliver information from the sensors to a host processor; and a process within the host processor for determining, from the absolute times of arrival of an event at two or more sensors, a position of the source of the event. Acoustic events are detected and analyzed at each sensor so that the sensor transmits over the network: an identifier for the sensor; an identifier for the type of event; and a precise absolute time of arrival of the event at the sensor. In a preferred embodiment, the system also identifies the type of weapon firing a gunshot.

Abstract: A method of locating an acoustic source, the method comprising sampling said acoustic source at a plurality of acoustic receivers having different locations, each acoustic receiver time-stamping a respective received acoustic sample using a system time, each acoustic receiver sending said time-stamped acoustic sample to a central controller, the central controller determining the location of the acoustic source in response to receiving the time-stamped sound source samples from the plurality of receivers.

Abstract: A method of providing an indication of the direction of a target such as a sniper. A rifle mounted sensor array detects an acoustic pulse originating from the target. The signal is processed to estimate the direction of the target, and an indication is provided when the weapon is aligned with the estimated direction. The direction of arrival of an acoustic pulse is estimated by spectrally decomposing each signal from the sensor so as to generate one or more spectral components for each signal, and processing the spectral components to estimate the direction of arrival.

Abstract: A system for locating an acoustic source from an acoustic event of the acoustic source. In one embodiment, the system includes a sensor network having a plurality of spatially separated sensor nodes each located in a predetermined position encountering acoustic waves generated by an acoustic event passing proximate to the plurality of spatially separated sensor nodes, where the plurality of spatially separated sensor nodes are synchronized to a common time base such that when the acoustic event is detected, information of the acoustic waves from each of the plurality of spatially separated sensor nodes is obtained and broadcasted through the sensor network. The system further includes a base station for receiving information of the acoustic waves broadcasted from the sensor network and processing the received information of the acoustic waves so as to locate the acoustic source of the acoustic event.

Abstract: Systems and methods for determining and disambiguating the location of the shooter of supersonic projectiles based on shockwave-only signals are described. Using several spaced sensors, an initial portion of the shockwave-only signals is sensed to determine Time-Differences-Of-Arrival (TDOA) for the sensor pairs. The resulting TDOAs are used to determine the gradient of curvature of the shockwave wavefront on the sensors. The gradient of curvature is then used to determine the disambiguated projectile trajectory.

Abstract: Systems and methods for compensation of sensor degradation in multi-shooter detection systems are described. In such systems, shooter position and trajectory can be estimated precisely from the shockwaves produced at the plurality of sensors by the incoming shots. However, sensor positions can shift and the performance of some sensors may degrade for various reasons. To compensate for sensor degradation that may occur over the life of a long-deployed system, the shooter estimation algorithms are dynamically adapted by performing a least-squares regression analysis of the shockwave arrival times to obtain a time residual for each shot, observing multiple shots, and weighting the individual contributions of the sensors as a function of the time residuals for the multiple shots.

Abstract: Systems and methods for locating the shooter of supersonic projectiles are described. The system uses at least five, preferably seven, spaced acoustic sensors. Sensor signals are detected for shockwaves and muzzle blast, wherein muzzle blast detection can be either incomplete coming from less than 4 sensor channels, or inconclusive due to lack of signal strength. Shooter range can be determined by an iterative computation and/or a genetic algorithm by minimizing a cost function that includes timing information from both shockwave and muzzle signal channels. Disambiguation is significantly improved over shockwave-only measurements.

Abstract: A system for detecting acoustic events comprising a wearable sensor comprising: a microprocessor; a microphone communicating with the microprocessor; a GPS module; a wireless network system; and a display screen; wherein: the microphone is in communication with the microprocessor allowing the microprocessor to detect the acoustic event; the GPS functions to determine the location of the wearable sensor; the wireless network system allows for the interfacing and sharing of data between the sensor and other components of the system for detecting acoustic events; and the system for detecting acoustic events functions to triangulate the location and time of the acoustic event, may be used to detect gunshots. Other acoustic events such as a patient alarm may also be detected using the system.

Abstract: Systems and methods for locating the shooter of supersonic projectiles are described. Muzzle blast signals are neither sought nor required. The system uses at least two sensors, with each sensor having a 3-axis accelerometer. The sensors are spaced apart at least 1 meter and have each a diameter of about one centimeter. The three accelerometer signals of each sensor represent pressure gradients and are processed to find the shockwave arrival angle unit vector, the shockwave arrival time instant and peak pressure. Noise signals seldom cause false detections with this sensing method because the sensors have maximum sensitivity at the high frequency characteristics of shockwaves, while their sensitivity to the low frequency characteristics of ambient noise is relatively low.

Abstract: A system for locating and identifying an acoustic event such as gunfire. The inventive system employs a plurality of man wearable acoustic sensors for detecting gunfire, each acoustic sensor having a display associated therewith for displaying information concerning the acoustic event to a user. In preferred embodiments, the sensor includes a microphone for receiving acoustic information; an A/D converter; a processor for processing the digitized signal to detect a gunshot and determine a time of arrival; a GPS receiver for determining the position of the acoustic sensor; and a network interface for bidirectional communication with a system server. Preferably the display comprises: an LCD; and an electronically readable compass. When the display and acoustic sensor are in separate housings, the acoustic sensor includes a transmitter and the display includes a receiver for transferring the gunshot information.

Abstract: An acoustic event location and classification system comprising an array of at least two acoustic transducers arranged spaced from one another; a central data processing unit for receiving signals from the acoustic transducers and processing the signals to determine a event type and location; and an internet or LAN connection for transmitting event type and location data to a third party, wherein the central data processing unit uses a DSNN to determine the event type and generalized cross correlation functions between microphone pairs to determine the event location.

Abstract: Shockwave-only solutions that estimate shooter position and shot trajectory are extremely sensitive to the quality and precision of the shock time-of-arrival (TOA) measurements as well as the accuracy to which relative sensor positions in space are known. Over the life of a long-deployed system, the sensor positions can shift and the performance of some sensors may degrade for various reasons. Such changes can degrade the performance of deployed shooter estimation systems. Disclosed are systems and methods that can be used to calibrate sensor positions based on shock and muzzle measurements processed from a series of shots fired from a known location and in a known direction, as well as an approach for dynamically adapting shock-only shooter estimation algorithms to compensate for sensor degradation and/or loss.

Abstract: The invention relates to a device that is used to analyse the structure of a material. The inventive device comprises: probe elements (5) which are used to (i) emit a wave, in the material, with emission delay laws that correspond to several simultaneous deviations and (ii) receive, on the different probe elements (5), signals from the refraction of said wave by the material; detection channels, each detection channel being connected to a probe element (5), in order to collect the refraction signals and to transmit same to data processing means (4); and delay circuits that apply a delay on each detection channel according to the reception delay laws which are predetermined and which correspond to the different deviations of the wave emitted. The invention also relates to an analysis method which can be used, in particular, on said device.

Abstract: A system and method for protecting sensor positions in an array of acoustic sensors which make up a gunfire locator system. The inventive system includes a purity of sensors and a host computer. Each sensor includes: a microphone for receiving acoustic information; a processor for processing acoustic information to detect an acoustic event and determine a time of arrival; a GPS receiver; an encryption module for encrypting transmitted sensor positions; and a network interface for transmitting sensor positions and times of arrival. The host computer includes: a network interface for receiving sensor transmissions; an encryption module for deciphering sensor positions; and a CPU.

Abstract: Systems and methods for locating the shooter of supersonic projectiles based on shockwave-only measurements are described. Muzzle blast signals are neither sought nor required. The system uses at least five, preferably seven, acoustic sensors that are spaced apart at least 1 meter. The sensor signals are acquired with a time resolution in the order of microseconds and processed to find and disambiguate the shockwave arrival angle unit vector. Two different Time-Difference-Of-Arrival (TDOA) measurement techniques are described, with one technique using counters in each signal channel and the other technique using cross-correlation between signal channels. A genetic algorithm can be used to efficiently disambiguate the results.

Abstract: A system and method for detecting, identifying, and fixing the location of the source of an acoustic event. The inventive system includes: a plurality of sensors dispersed at somewhat regular intervals throughout a monitored area; a communication network adapted to deliver information from the sensors to a host processor; and a process within the host processor for determining, from the absolute times of arrival of an event at two or more sensors, a position of the source of the event. Acoustic events are detected and analyzed at each sensor so that the sensor transmits over the network: an identifier for the sensor; an identifier for the type of event; and a precise absolute time of arrival of the event at the sensor. In a preferred embodiment, the system also identifies the type of weapon firing a gunshot.

Abstract: Given a trajectory and unit pointing vectors determined based on a planar or other approximation of a shock wave, a method and apparatus are provided to calculate times the sensors should have detected, based on a conical geometry of the shock wave. A difference between the calculated times and the actual times measured by the sensors may be minimized. The minimization may be performed by perturbing the unit vectors. When the perturbation of the unit vectors results in an acceptable difference between the calculated times and the measured times, an accurate trajectory of the projectile can be generated from the perturbed unit pointing vectors.

Abstract: A firearm discharge detection device and alarm system featuring a plurality of detector units placed inside a structure which communicate with a central monitoring unit. Each detection unit will detect the discharge of a firearm in its proximity from decibel levels and duration using on board filters and timers and thereon signal the central monitoring unit. A digitized embodiment may also be used to determine the sound of a firearm using a digitized fingerprint of the sound compared to an library of firearm sounds in onboard memory by a microprocessor. The central monitoring unit will thereupon communicate with all the other detection devices installed to sound an audible and/or visible alarm to occupants to exit. Concurrently the central monitoring unit will communicate the firearm discharge and location to police. An optional directional exit alarm or warning to hide may also be activated.

Abstract: A remote acoustic detection system includes at least one detection unit delivered to a remote or inaccessible location by a missile or other aircraft. The detection unit monitors acoustic events at the location such as aircraft takeoffs and landings and preferably is provided the capability of classifying the events, for example, as to the event or type of aircraft. A sleep mode can be provided to conserve power such that the unit is activated only in the presence of threshold acoustic levels. The unit also includes a wireless transceiver for relaying data to a central monitoring authority, which may be a passing or loitering aircraft. Each detection unit may be provided with an address for allowing monitoring of a network of detection units.

Abstract: A system for detecting gunshots includes an input device including a microphone for converting acoustic noises into signals and amplifiers for amplifying the input signals, a threshold detector for receiving the amplified signals and comparing the signals with a predetermined threshold value and for producing an output signal when the threshold value is exceeded. A pulse width detector is connected to the threshold detector for producing an output signal only if the width of the threshold detector output signal is within a predetermined range of values. A pulse count detector is also connected to the threshold detector for producing an output signal when the level of the threshold output signal is above a peak threshold level or the number of threshold level output signals that exceed a threshold level are less than a preset limit. An output device indicates that a gunshot has occurred only when signals are received from the pulse width detector and the pulse count detector during a sampling period.

Abstract: A low cost and highly accurate sniper detection and localization system uses observations of the shock wave from supersonic bullets to estimate the bullet trajectory, Mach number, and caliber. If available, muzzle blast observations from an unsilenced firearm is used to estimate the exact sniper location along the trajectory. The system may be fixed or portable and may be wearable on a user's body. The system utilizes a distributed array of acoustic sensors to detect the projectile's shock wave and the muzzle blast from a firearm. The detection of the shock wave and muzzle blast is used to measure the wave arrival times of each waveform type at the sensors. This time of arrival (TOA) information for the shock wave and blast wave are used to determine the projectile's trajectory and a line of bearing to the origin of the projectile. A very accurate model of the bullet ballistics and acoustic radiation is used which includes bullet deceleration.