Raytheon BBN tests state-of-the-art shooter detection system

Figure 1 State-of-the-art shooter detection system

"Using Chameleon turnkey software and the NI PXI hardware platform, along with source code control based on NI LabVIEW and data acquisition software, we can measure more than 32 channels of pressure sensor data, and the system can be further expanded while keeping time synchronized with the instantaneous shooting events on the range."

- Jeff Mazurek, Raytheon National Security Bureau

challenge:

Acquire time-synchronized data from the range and other environments to test and improve the Boomerang shooter detection system.

Solution:

Multichannel data was acquired and recorded using the flexible, PXI-based Chameleon data acquisition system from PVI Systems.

Raytheon BBN is a high-tech company that provides product research and development services. The company's expertise covers information security, speech and language processing, networking, distributed systems, and sensing and control systems, in which BBN's scientists and engineers have accumulated a large number of innovative and patented solutions. Testing work in the field of acoustics requires large-scale computing, which has brought some business opportunities, such as the Boomerang shooter detection system.

The Boomerang system uses an array of seven microphones to detect the direction of fire from the shock wave and muzzle blast of small arms fire, pinpointing the shooter's azimuth, range and altitude in less than a second. A clock face shows the direction of fire, while the recorded sound indicates the direction and distance. Azimuth, range and altitude are displayed on an LED display. [page]

The Boomerang system has algorithms that can be used by the user to suppress return fire events. The Boomerang system generally does not generate false alarms due to non-shooting events, such as bumps in the road, slamming doors, wind noise; or other external noise events, such as traffic noise or firecrackers. The system requires a lot of signal processing and testing algorithms to maintain reliability and robustness under various operating conditions and eliminate various false alarms.

System installation and testing

We recently tested the system successfully in a large open-air football stadium, where we simulated crowd noise and reverberation. We have also successfully tested the system in U.S. military operations at an urban terrain training facility. More than 10,000 systems have been deployed by the military.

As part of our ongoing efforts to improve our Boomerang system, we decided to replace an old data acquisition system. After comparing other solutions, we preferred the NI PXI platform, but we wanted a solution that would be as ready-to-use as the old system. After consulting with our local NI regional sales engineer, we learned about and ultimately selected the Chameleon DAQ system from PVI Systems.

Chameleon is a flexible and scalable turnkey system that is based on PXI data acquisition systems. It relies on the NI PXI-449X dynamic signal acquisition module (to acquire data from the microphones) and the NI PXI-668X timing and synchronization module. We plan to integrate other sensors in the future. The module has an amazing sampling rate of up to 204.8 kS/s in 24-bit dynamic signal acquisition mode. As we tested and improved the system, we were always able to collect data from many channels at high sampling rates. With this new system, we can easily adjust the sampling rate to optimize the overall performance of the system.

Flexibility and functionality

The Chameleon system provides built-in capabilities for different data acquisition applications, including: I/O channel synchronization, time and frequency signal acquisition, real-time monitoring of all channels, and post-acquisition data display and processing. It supports reconfigurable hardware to run multiple test projects, which is very important for the various tests we need to run. Using Chameleon turnkey software, the NI PXI hardware platform, and source code control based on NI LabVIEW and data acquisition software, we can measure more than 32 channels of pressure sensor data, and the system can be further expanded while keeping time synchronization with the shooting events happening on the range.

The flexibility of the system is very useful for us. We can use the system to export data to popular file formats such as .mat, CSV, .uff, and TDM streams for post-processing analysis. We can easily configure the system quickly and save files using common time series formats such as GPS time stamps or simple names. There are many events generated when conducting live-fire tests, and the system allows us to easily implement data logging. When you want to observe real-time signals, you can use the built-in spectrum analysis tool, which is very convenient. We can also set thresholds for events to use the pre-trigger system function without affecting data quality.

After more than a year of use in harsh conditions, the Chameleon data acquisition system has proven to be a rugged and reliable system. After installing the system in the field, an external connection was provided to easily connect to the system. Operators can connect to the system via remote desktop and the data is quickly transferred to our network. We plan to use this system for the next few years and share it with other teams in our company.

Figure 2 Boomerang system display panel

Figure 3 Chameleon data acquisition panel