While today’s law enforcement officers don’t wear utility belts full of crimefighting gadgets like Batman, they do rely on a variety of state-of-the-art technologies to do their jobs efficiently and safely.
Two of these devices—down-the-road (DTR) radar used in speed enforcement and the ballistic chronograph, which measures the speed of bullets—soon should be more useful tools thanks to recent research conducted by the Office of Law Enforcement Standards (OLES) at the National Institute of Standards and Technology (NIST).
In a forthcoming paper in The Journal of Research of the National Institute of Standards and Technology,* researchers John Jendzurski and Nicholas Paulter examined the four methods commonly used by law enforcement officers to calibrate DTR radar devices and, for each one, determined the uncertainty it places on the measurement of a moving target. The calibration methods studied included a radar target simulator (an audio frequency source best used in a test facility and designed to mimic various speeds of a moving object), tuning forks (provide a range of audio frequencies that simulate different vehicle speeds and are easily used in the field), a calibrated speedometer (where the DTR measurement is dependent on accuracy of the test car’s speedometer) and a fifth wheel (using the measured speed of a wheel attached to the rear of the test vehicle instead of relying on the car’s speedometer).
Based on the data they obtained, the researchers developed and published uncertainty measurement formulas for each calibration method. These formulas will help DTR radar users clearly understand the impact of proper calibration for making accurate speed measurements.
In the second OLES publication, a paper in the April 2009 issue of Optical Engineering,** researchers Donald Larson and Nicholas Paulter developed a ballistic chronograph—an instrument used to measure of the velocity of a fired bullet—that is 20 times more precise than a typical manufacturer-provided chronograph. The new instrument has an uncertainty of only ± 0.2 meters per second compared to ± 4 meters per second for a bullet travelling 400 meters per second. The NIST chronograph may be used as a reference standard to calibrate and/or characterize the performance of chronographs available on the market. Law enforcement agencies and the military use chronographs during the testing of ballistic resistant body armors (commonly, but inaccurately, known as “bulletproof vests”) because their effectiveness is determined by how many bullets fired at specific velocities perforate or don’t perforate the protective gear.
* J. Jendzurski and N.G. Paulter. Calibration of Speed Enforcement Down-the-Road Radars. Journal of Research of the National Institute of Standards and Technology, Vol. 114, No. 3 (May-June 2009).
** N.G. Paulter and D.R. Larson. Reference Ballistic Chronograph. Optical Engineering, Vol. 48, No. 4 (April 2009).
Michael E. Newman | Newswise Science News
When your car knows how you feel
20.12.2017 | FZI Forschungszentrum Informatik am Karlsruher Institut für Technologie
Did you know how many parts of your car require infrared heat?
23.10.2017 | Heraeus Noblelight GmbH
On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.
We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
19.01.2018 | Materials Sciences
19.01.2018 | Health and Medicine
19.01.2018 | Physics and Astronomy