February 4, 2006 15:31 - StarChase: "Let them go, we will arrest them later"
There are more than 100,000 high-speed pursuits in the U.S. every year, endangering everyone involved in the chase-the suspects, the police, and the public. And it's an unnecessary danger; up to eighty-five percent of these pursuits are initiated by non-violent offenders. Plus, the economic impact is staggering, with hundreds of millions paid out in the U.S. annually, due to insurance payouts, medical bills, workers' compensation and lost wages.
The StarChase system is made of a commercial off the shelf (COTS) oriented solution. It's comprised of a tracking projectile with a miniaturized GPS receiver, radio transmitter, power supply and a launcher which can be hand-held or mounted on a police car.
The police car only has to come close enough to the suspect's car once in order to launch the tracking device. Once the gun is fired a sticky dart fitted with a GPS will be propelled from the officer's car, which will stick to the fleeing vehicle allowing the police to track its location without the need for a chase.
Each StarChase device can fire 2 GPS enabled darts, in case the first one misses or does not stick to the target vehicle. The GPS tag will activate on impact, and will transmit the car's position via a wireless modem. An encrypted cellular backbone will deliver continuous location updates to the StarChase server, which will pass on the information to authorized users via a password-protected Web portal, allowing the dispatch center to view the suspect vehicle in real-time. Through efficient use of technology, a high-speed chase has been replaced with an interdiction strategy.
StarChase is a powerful tool law enforcement can use to reduce hazards and liability issues. It saves money and it saves lives.
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February 7, 2006 17:28 - Why are the rules for microwave ovens much more severe than for cell phones?
A research about the use of cell phones by young children brought us a lot of articles about eventual hazardous effects of exposure to RF energy. Roughly we can say that money-oriented groups declare that everything is OK. After all it has never been scientifically proven that cell phones are dangerous. Massive cell phone usage exists only during the last ten years. If in ten or twenty years from now it would become clear that this technology is not so innocent at all, it will be too late for hundreds of millions, even billions, of users.
More people-oriented groups warn to limit the usage of cell phones to an absolute minimum. They also warn for the millions of cell phone towers in populated areas, even on buildings and schools. Several grouped antennas emit RF energy; about 300W each. People live; work and sleep near or even under these antennas and don't feel well or even sick. But, of course, these are pure psychological symptoms.
As often, politics-oriented groups can not decide which side to choose: the huge economic interests or public safety. They don't go further than to say not to exaggerate the use of cell phones, especially not by young children.
And now the figures
Microwave Ovens
A microwave oven produces 500-1500W of RF energy at a frequency of 2.45GHz. These are extremely dangerous levels and every oven has several protections against too much leakage of this energy to the outside of the device.
The maximum microwave radiation leakage permitted by the Radiation Emitting Devices regulations for microwave ovens operated with a load, is 1.0 mW per square centimeter measured at 5cm from any external surface of the oven.
Cell Phones
Cell phones can vary the power that they emit. In case of obstructions or great distances to a cell tower, a GSM device can emit up to 2W at frequencies of 1.8 or 1.9GHz (comparable to the 2.45GHz of microwave ovens). The AVERAGE radiation rate of cell phones is regulated. The rate at which radiation is absorbed by the human body is measured by the Specific Absorption Rate (SAR), and its maximum levels for modern handsets have been set by governmental regulating agencies in many countries. In the USA, the FCC has set a SAR limit of 1.6 W/kg for most parts of the body.
This does not scare the general public. Who does yet understand anything?
Antennas in cell phones are very small. Not much more than 1 square centimeter. When talking on the phone this antenna is hold against the head at a distance of 1cm maximum. The antenna is omni-directional, so not all of the energy will pass into the head. If only 20% goes in the direction of the head the power density at 2W output is still 2000/5 = 400 mW per square centimeter.
This is 400 times the norm for microwave ovens at a distance of 5cm from the oven. Nobody holds his/her head at a distance of 5cm from a microwave oven for any longer period than 2 seconds. At the more normal distance of 50cm (ten times 5cm) the power density at head level from a microwave oven is maximum 1/100 = 0.01 mW per square centimeter. And that only during a couple of minutes per day. This compared to a cell phone use of several hours daily by many people.
A USAF/AFRL simulation showed a calculated specific absorbed radiation (SAR) distribution in an anatomical model of a human head next to a 125mW dipole antenna at 1.9GHz. The peak SAR was 9.5 W/kg. The AVERAGE SAR was only 0.008 W/kg. The AVERAGE in the head was far below the limit, but even at 125mW emitted power the ear got almost six times too much. How much would this be at an emitted power of 2W?
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February 27, 2006 17:48 - Cell phones for kids
Kid phones are very handy for children to let their parents know about, say, school scheduling changes and they reassure parents that they can reach their kids at any time. These contacts can easily be limited to a maximum of one or two minutes per week and this way a cell phone for kids could maybe be justified. Read more...
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