For more than fifteen years, 01dB-METRAVIB has been leading the way in developing technology for detecting sounds on the battlefield. This article talks about the latest improvements in Gunfire Detection Systems (GDS), which use sound and special processing to find and pinpoint where gunshots are coming from. These gunshot detection systems can determine the direction, height, and distance of the gunfire. Often, these sound sensors are combined with other technologies like cameras, thermal imaging, and LASER systems to work better and be more versatile.
Introduction
01dB-METRAVIB uses its expertise in acoustics and vibration to detect and locate threats for security purposes. The company’s focus on detecting small-caliber gunshots began in response to the “sniper valley” scenario during the Bosnian conflict in Sarajevo. This led to various research programs, such as SYMSATI and DITIREMB, which integrated acoustics, optronics, and LASER technology. More recent programs like DAOTE, ARTEMIS, and CELACANTE have improved wireless technology and reduced false alarm rates in gunshot detection.
The company’s PILARw system, used worldwide by armed and security forces, shows the effectiveness of these technologies in real-world situations.
The PILARw system is an acoustic Gunfire Detection System (GDS) designed to detect and locate small-arms fire. It includes:
- One or two acoustic arrays with embedded microphones and electronics
- A compact signal processing unit
- A laptop for displaying results
The system is available in two configurations:
- Ground-based: Uses two acoustic sensor arrays to locate the origin of the shot in 3D and display the bullet trajectory. It can locate shots within ±2° in bearing and ±20% in range, with a detection range over 1000 meters.
- Vehicle-mounted: Adapted for stationary and moving vehicles, providing situational awareness up to speeds of 45 km/h.
Acoustic Wave Exploitation: A gunshot generates two distinct acoustic waves: the muzzle blast (MB) and the shock wave (SW). These are analyzed using Time Of Arrival (TOA) and Direction Of Arrival (DOA) to estimate the shooter’s location.
New Multi-Array Systems: The DAOTE program has introduced new systems featuring multiple acoustic arrays that are interconnected wirelessly. These advancements expand coverage areas and significantly enhance the accuracy of detecting and pinpointing sources of sound through sophisticated data fusion techniques.
System with Three Arrays: One notable system developed under this program is the Radio Acoustic PILAR GDS (RAGDS), which utilizes three acoustic macro-sensors. Each sensor is equipped with a tetrahedral array, along with additional components such as GPS, compass, temperature sensor, and radio antenna. By integrating data from these sensors, the RAGDS system achieves higher precision in localizing sound origins.
Wireless Technology: Wireless technology plays a crucial role in these systems, facilitating data transmission between beacons and the concentrator module using radio frequencies within the ISM band (869.4 MHz to 869.65 MHz). This approach ensures quick deployment, seamless communication, and effective data transmission over distances of up to 1000 meters in open environments.
Data Fusion: Data fusion techniques employed in these systems combine information from multiple arrays, significantly improving the overall performance in detecting and localizing sounds. This integration results in more accurate azimuth (direction), elevation, and distance estimations, enhancing operational effectiveness in various scenarios.
Camera Coupling and Additional Sensors PIVOT System: This portable system includes a pan-and-tilt turret with a day/dawn camera, integrated with PILARw to provide real-time imaging of the shot origin. It can also record images using an optional DV-CAM recorder.
Infrared Camera Option:The system can also include an IR camera for thermal visualization, operational both day and night.
Laser Integration: In the DAOTE program, PILARw is paired with a LASER system for enhanced threat detection, with co-located daylight and IR cameras for visual confirmation.
The Bullet Detector Concept: Operational feedback indicated a need to limit PILARw triggering to aggressive shots only. The Bullet Detector accessory meets this requirement by triggering only when a supersonic bullet passes within 50 meters of the sensor arrays, reducing false alarms.
ShotGuard V2 Software: The new software version includes control for the Bullet Detector and various improvements for urban environments.
Conclusion
In conclusion, 01dB-METRAVIB’s ongoing advancements in Gunfire Detection System (GDS) technology, driven by the demands of battlefield environments, have yielded systems with significantly improved localization accuracy and minimized false alarms. By integrating multiple arrays, employing advanced data fusion techniques, and incorporating additional sensors such as cameras and LASERs, these systems now offer expanded capabilities for detecting and recognizing threats comprehensively. This continuous evolution ensures that 01dB-METRAVIB remains at the forefront of enhancing security and operational effectiveness in dynamic and challenging scenarios.
Acknowledgments
We gratefully acknowledge the support of the following organizations for their contributions to these developments:
- French Defense Procurement Agency (DGA)
- United States Army Research Laboratory (US-ARL)
- United States Army Special Operations Command (USASOC)
References
For further reading on the foundational principles and studies related to small arms fire detection systems, the following references are recommended:
- Works by G.B. Whitham and U. Ingard
- Studies by P. Naz et al.
- Publications by Donzier and Cadavid