“Using Chameleon turnkey software, the NI PXI hardware platform, and source control based on NI LabVIEW and DAQ software, we can measure more than 32 channels of pressure data from our sensors with expansion capabilities while maintaining time-synchronized data from transient shot events on the firing range.”
Jeff Mazurek – Raytheon BBN
Raytheon BBN is a high-technology company that provides research and development services. With expertise spanning information security, speech and language processing, networking, distributed systems, and sensing and control systems, BBN scientists and engineers have amassed a substantial collection of innovations and patented solutions. The extensive calculations required for acoustics work lead to business opportunities like the Boomerang shooter detection system.
Using an array of seven microphones, Boomerang detects the direction of incoming small-arms fire from the shock wave and muzzle blast, indicating the azimuth, range, and elevation of the shooter in less than one second. A clock face display shows the direction of fire and a recorded voice announces the direction and range. Azimuth, range and elevation are displayed on an LED screen display.
Algorithms in the Boomerang system suppress return fire events by users. Boomerang does not generate false alerts commonly caused by non-ballistic events, such as road bumps, door slams, and wind noise, or other extraneous noise events such as vehicle traffic or firecrackers. The system requires extensive signal processing and testing of algorithms to provide reliable and robust performance over a wide range of operational conditions as well as eliminate false positives.
System Setup and Testing
We recently tested the system successfully in a football stadium with simulated crowd noise and reverberation. It was also successfully tested in a US Military Operations in Urban Terrain training facility. Over 10,000 systems are currently fielded by the military.
As part of the ongoing improvements to Boomerang, we decided to replace an older DAQ system. While considering other solutions, we liked the NI PXI platform, but we wanted an out-of-the-box solution like the old system. Working with our local NI field sales engineer, we learned about and ultimately chose the Chameleon DAQ system from PVI Systems.
The Chameleon system is a flexible, scalable, turnkey, PXI-based DAQ system that works with the NI PXI-449x dynamic signal acquisition modules used to record data from the microphones as well as NI PXI-668x timing and synchronization modules. We plan to incorporate other sensors in the future. The DAQ rates, up to 204.8 kS/s for 24-bit dynamic signal acquisition, are simply amazing. When testing to improve systems, we often collect many channels of data at high sample rates. With this new system, we can easily adjust our sampling rate
to optimize overall system performance.
Diverse Flexibility and Functionality
The Chameleon system provides built-in functionality for diverse DAQ applications for I/O channel synchronization, time and frequency acquisition, live monitoring of all channels, and post-acquisition data display and processing. It supports reconfigurable hardware for multiple test programs, which is important for the variety of tests that we need to run. Using Chameleon turnkey software, the NI PXI hardware platform, and source control based on NI LabVIEW and DAQ software, we can measure more than 32 channels of pressure data from our sensors with expansion capabilities while maintaining time-synchronized data from transient shot events on the firing range.
The flexibility of the system works perfectly for our staff. We can use the system to export data to popular file formats such as .mat, CSV, .uff, and TDM streaming for post-processing analysis. It’s easy to configure the system quickly and save the files in a time series format using conventions such as GPS time tags or simple names. Conducting live fire tests results in many events, and this makes handling bookkeeping features easy. The built-in tools for spectral analysis are a handy feature when you want to observe signals in real time. We also use the pre-trigger functionality of the system by setting thresholds for events and have had no issues with data quality.
The Chameleon DAQ system has proven to be rugged and reliable after more than a year of use in harsh conditions. Mounted in a field case, the system has external connections for easy connection. Operators can communicate with the system via remote desktop. The data then can be quickly put on our network. We plan to use the system for years to come and share it with other groups at our company.