Since 9/11 virtually all members of the law enforcement community have become soldiers in the war on terrorism. Even the more traditionally "peaceful" jobs, such as rural border control, park rangers and Bureau of Land Management scouts, are feeling the need for the latest technology and skills to deal with the unexpected.
Whether a result of the expanded role of law enforcement, increased emphasis on homeland security or dramatic data about dangers of the dark, the need for low-light technology and training has developed into a high priority. The importance of "owning the night" is no longer restricted to the battlefield.
From the front line to the blue line
Cutting-edge technologies such as image intensified night vision and thermal imaging were originally developed for and deployed by the military. These same technologies are becoming essential in protecting law enforcement agents in increasingly complex and dangerous environments, as well as in enabling them to do perilous jobs more effectively and efficiently.
FBI data for law enforcement officers killed in the line of duty between 1995 and 2004 reveals that more than 65 percent of these deaths occurred between 8 p.m. and 8 a.m. It's widely agreed that nighttime is the best time for bad guys to sneak around and do bad things, and a time when low-light technology is powerful to possess. But good low-light equipment is not cheap and circumstances in the field vary widely.
Are officers monitoring wild horse poachers on a Nevada desert or searching for a missing child in an urban area? Are they escorting explosive cargo through a city harbor or tracking an escaped convict through the woods?
Depending on the type of patrol, goals of the mission and ambient lighting factors, the choice in low-light equipment can vary greatly.
Image intensified night vision
The most popular and common type of night vision is based on image intensification technology. Image intensifiers amplify available visible and near infrared light to achieve better vision. This amplification has its benefits and its drawbacks. It provides users with high image resolution, but excessive ambient light can cause the device to be ineffective.
"Night vision is successful for us because we generally operate under a more rural night sky," says Col. Mike Bise of the Virginia Department of Game and Inland Fisheries. "In contrast, sudden bursts of ambient light, combined with the irregular lighting of the urban environment, has caused problems for users of early versions of night vision equipment in the urban setting."
Phillip Terenzi, harbormaster for the Boston (Massachusetts) Police Harbor Unit, has found a unique way to alleviate some of the ambient light issues.
"We discovered that our 3x magnification lens helps mitigate the interference of the bright lights of the urban night landscape," he says. "Now we have ordered a 5x magnification lens and expect this will help our inner harbor night vision even more."
According to Max Rivkin, president of Burlington, Massachusetts-based N-Vision Optics, magnification lenses narrow the device's field-of-view, therefore diminishing the adverse effects from bright light sources outside of the field-of-view.
The evolution of night vision devices to Generation 3 (Gen 3) also has led to significant strides in overcoming unexpected, and harmful, light exposure.
"Prolonged exposure to bright light can blow out the (image intensification) tube inside a night vision device," describes retired Lt. Col. Al Pavsner of the U.S. Marine Corp. "However, the more sophisticated Gen 3 products eliminate this danger. They offer a gated power supply which reduces halos on subjects, as well as alleviates the blooming of light, and protects the tube from bright source damage."
"Gen 3 devices are far and above a superior product to the earlier generations," agrees Bise.