Los Angeles Tests Gunshot Sensors on Light Poles

Los Angeles is testing sensors attached to streetlights to wirelessly detect gunshots and other noises, and may expand the service to include sensors to recognize air pollution and earthquakes. Dozens of cities globally, including New York, began monitoring gunshot sounds with sophisticated rooftop sensor technology that measured two to three feet in length more than a year ago. However, newer sensors to detect gunshot sounds that are being tested by L.A. are smaller, about 1.5 inches in diameter, and can be placed farther apart, on a light pole every 10 blocks, according to Ed Ebrahimian, director of the city's bureau of street lighting. These gunshot detection sensors are being tested on some of the 25,000 poles that already have wireless controllers installed for turning city streetlights on and off remotely and for monitoring, he said. "Now we are taking the next step with gunshot detection sensors and working closely with Philips [Lighting]," the manufacturer, he said. "We can easily connect [the gunshot information] with 911 and instantly detect gunshots in high crime areas," Ebrahimian said. "With 911, we can send police cars to a location in minutes. If we can send a car five minutes earlier and save someone's life, we've done our job." The light pole controllers can also be equipped with inexpensive sensors for general noise levels and have been tested successfully next to an elementary school where peaks in noise were detected when school children were outside. Sensors to detect earthquake tremors, pollution and moisture are also under consideration, Ebrahimian said. "Our first phase is to have sensors without cameras, but really the sky's the limit" on what can be detected, he said. L.A. police already use cameras in high crime areas, but that information is handled on a separate network infrastructure from the city's streetlight network, he said. L.A. already has seen energy and repair savings by installing LED lighting on 170,000 of the city's 219,000 streetlights. For that project, begun in 2009, the city spent $65 million to retrofit older streetlights with efficient LED lights. Some of the newer models are expected to last up to 15 years. About $9 million a year has been saved in energy costs, Ebrahimian said. The city has also seen a dramatic drop in streetlight maintenance in the shift to LED, going from 24,000 repairs before the program started down to 10,000 last year. While the return on investment with LED lights is clear, Ebrahimian said there's no established financial ROI for the sensors that will be attached to street poles. Each sensor could cost $150 or more when installed. While the sensor benefits are not directly measureable in dollars, they can bring other benefits because they will help city planners and elected officials respond more directly to city problems and citizen needs, he said. "Frankly, for all cities, you need someone at the top to be able to support sensor tech like this that is cutting edge," Ebrahimian said. "Mayor [Eric] Garcetti has given us amazing support. He's a tech person and embraces all this new technology and is excited by the LEDs and sensors and controls." Last year, Garcetti talked about the city's lighting and "smart pole" program at a conference, mentioning streetlight cameras that were then being used to spot illegal trash dumping. He also suggested that public Wi-Fi could be attached to city streetlights. "The mayor calls our streetlights 'information beacons' where data can be disseminated to fire and police and planning officials and the mayor or whoever, so the city can do data analysis and we can put it on a dashboard," Ebrahimian said. For other city governments weighing smart city technology, Ebrahimian advised not using any single manufacturer to provide sensors, controllers or LEDs. Cities need to perform their own rigorous evaluations of vendor products as well. Contracts should be kept to short terms, of one to two years, he added. "We do not give three to four year contracts," he added. "We do not trust everything manufacturers are claiming." However, Ebrahimian also said city governments "should jump on LED lighting" because LEDs are more than 80% more energy-efficient than older technology. "I do not understand why cities are so slow to implement LED," he said. "What is holding them back?" Philips Lighting, which was spun off from Royal Philips last year, first announced a partnership with the city of Los Angeles in 2015 to install smart poles that work with controllers and 4G LTE wireless from Ericsson. Last month at Mobile World Congress, the two companies announced a newer generation of the smart pole technology for use in European cities. Other vendors also showed smart light pole technology, including Verizon and AT&T. ShotSpotter makes sensors that can detect gunshot noises which can be put on streetlight poles and roofs. The company has deployments in 90 cities worldwide, including San Francisco.


A 2004 meta-review of studies found drivers consistently recognized fluorescent colors faster, more consistently and from farther way than standard colors. Fluorescent material reflects non-visible ultraviolet light back in the visible spectrum, making it look about 200 percent brighter in daylight than conventional colors. There's no research on which color creates the best contrast, but fluorescent orange is a good pick because it's commonly used on highway safety and construction signs (ie. drivers associate it with caution), and orange is rare in the natural environment. Keep in mind that fluorescents simply do not work at night, when there's no natural sun for the fabric to reflect. Artificial light sources like car headlights and street lamps do not emit UV light either. At night your fluorescent yellow jacket is no brighter than anything else in your closet. Tenga en cuenta que los fluorescentes simplemente no funcionan de noche, cuando no hay sol natural para que la tela se refleje. Las fuentes de luz artificial como los faros de los automviles y las farolas tampoco emiten luz UV (ultravioleta). Por la noche tu chaqueta amarilla fluorescente no es ms brillante que cualquier otra cosa en tu armario. At night, your best bet for visibility shifts from bright colors to reflective material, which shines (literally and figuratively) in artificial light. Since reflectives can be expensive and often impair the breathability of the garment, it's important to be selective with placements-which brings us again to biomotion. A 2012 study by Dr. Tyrrell and other researchers found that drivers correctly identified a rider wearing a reflective vest 67 percent of the time; the rate jumped to 94 percent when ankle and knee reflectors were added. "A jacket has no movement, so a driver could see it as a road sign," says Trek Product Designer Kurt Heggland. "When you put the reflective material in places that move, you become more recognizable." Also, reflective material higher up on the body may not capture and reflect as brightly from light sources such as car headlights, which are aimed low. One thing to remember is to make sure you have enough reflective material. The reflective piping on lots of garments is simply too small to make a difference, says Dr. Tyrrell. To create contrast, the material must be large enough to draw attention and pop out of the background. For comparison, the minimum ANSI recommendation for reflective material on road workers' apparel is 155 square inches, equivalent to a 10x15 square patch. And do not forget your wheels. "Reflective-sidewall tires are more effective than clothing in some cases," says Trek's Michael Browne. They are so distinctly different from other reflective elements that, when drivers see them, they instantly recognize them as belonging to a bike. Because they convey both brightness and a sense of motion, flashing lights work well even during the day. A 2012 study in Denmark found riders with so-called "permanent running lights" had a 19 percent lower "multi-party" crash rate than a control group without running lights. It sounds counterintuitive, but in the brighter ambient light of daytime, you actually need a more powerful light than at night. Rating brightness is sometimes problematic because light output is measured various ways and brightness also depends on reflector design, but 20 lumens is a good minimum output for a rear light in daytime use (more is better) . Flashing front and rear patterns draw attention and set you apart from your environment during the day, but at night, it's best to use a steady pattern for the headlight unless you are in a brightly lit urban environment. Also, take care to angle the beam correctly; many rear lights have reflectors angled for maximum brightness when mounted on a seatpost. "In some of our research with rear lights, if the angle is off even 10 percent, brightness is greatly reduced," says Jon Quenzer, an electronics design engineer at Trek. SEE INTO THE FUTURE Improved batteries and technology like printable and flexible LED lights open up other possibilities for the future. For two years now, POC has shown a prototype wind vest and jacket with printed LED lights on the back, creating a flexible pattern of dots that creates a large total lit area out of very small light sources. Startup Lumenus is creating packs and apparel with built-in LED lighting on flexible strips. But Dr. Tyrrell sounds a note of caution about going crazy with lights. "We do not have enough data on how drivers process visual information," he says. LED lighting, if not done well, could potentially confuse drivers who can not quickly recognize what it is that they are looking at. POC's Huss says for that very reason, in developing the Light Vest, the company consciously decided to go with a gray/blue LED light color to mimic a reflective look. The next step may not involve vision at all, but active safety systems similar to the emergency braking and lane-departure warnings that are already in place in many new cars. Garmin's Varia radar system, for example, can warn riders of vehicles rapidly approaching from behind. And even more sophisticated technology may be coming. POC is in the second year of a collaboration with fellow Swedish company Volvo. At the 2015 Computer Electronics Show in Las Vegas, the companies demonstrated a technology that paired warning systems in the car to a rider's helmet. "The car is connected to the cyclist with a cloud service, and the driver and the rider are both alerted to the other one, even coming around a corner where they could not see each other," says Huss. The product is still a prototype demo, but Huss says it uses existing technology. "Everything is there," says Huss. "It's just about deciding what we want to do, and convincing the customer that they should pay for it." Perhaps, one day, autonomous vehicles will return fluorescent colors to the province of second-division Italian pro teams. Until then, when it comes to safety, grabbing as much attention as we can, as early as we can, remains our best bet. Pero el Dr. Tyrrell tiene una advertencia de cuidado de no volverse loco con las luces. "No tenemos suficientes datos sobre cmo los conductores procesan la informacin visual", dice. La iluminacin LED, si no se hace bien, podra confundir a los conductores que no pueden reconocer radamente lo que estn mirando. Huss de POC dice que, por esa misma razn, al desarrollar el chaleco de luz (Light Vest), la compaa decidi conscientemente usar un color de luz LED gris/azul para imitar un aspecto reflectante. Lindsey, J. (January 12, 2017). The Science of Being Seen: A Guide to Safe Riding,

2. Can anyone help me convert an electronic led lighting system from the UK to the USA household...?

if the transformer does say exactly "100-250" then it's actually an active regulated power supply and it will take in any voltage in that range and most any Hertz. A true transformer is not so flexible.

3. Can plants be grown using LED lighting without any sunlight?

They seem to do quite well on the Space Station.How Do Plants Grow in Space?

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