(top) These active infrared illuminators help cameras see clearly at night. (middle) Illuminators can be mounted in various configurations with cameras. (bottom) Sempra Energy of San Diego uses active infrared illuminators installed by P.A.C.E. to provide night vision for its facilities.

Since the events of Sept. 11, 2001, energy has been identified for major protection initiatives by the Department of Homeland Security. The importance of the energy infrastructure was seen again during the massive 2003 blackout that affected more than 50 million people in the northeast United States and Ontario.

In bringing energy sector clients into the post-9/11 world of physical security, California-based integrator Proprietary Access Control Enterprises Inc. (P.A.C.E.) saw a consistent theme emerge.

"Almost all of the surveillance systems I was asked to upgrade basically had no night vision capability," observed Raymond Downs, owner of P.A.C.E. "This was a real problem considering that the security at an energy company could ultimately affect millions of people."

One of the key challenges that Downs faced was the extensive target surveillance areas covered by pan-tilt-zoom (PTZ) cameras. The size of the sites made it impractical to propose that new lighting be installed, a solution that also would be very expensive. Downs solved the night vision problem by using active-infrared illumination, a kind of "invisible light" that can be targeted for strategic surveillance areas.

Active-infrared illumination is light that lies in the wavelength region of 700nm to 1,000nm. Its wavelength is just beyond the visible region (400-700nm), making active-infrared light invisible to the unaided human eye.

Most monochrome CCTV cameras will have some level of sensitivity to active-infrared light, with some cameras performing better than others. The term "active" differentiates from other night vision technologies such as thermal imaging and intensified CCDs, both of which are "passive" systems.

Active-infrared systems use illuminators that actively create light so that CCTV cameras can form clear, high-resolution images.

However, Downs had to do more than just apply active-infrared illumination. He needed the right kind of active-infrared.

"The PTZ cameras I came across had poor performance under certain wavelengths of infrared," Downs complained. "I had to know the wavelength at which the camera would respond the best and find an illuminator that output IR at that wavelength."

Downs determined that the particular cameras that most of his clients used were most responsive to lower infrared wavelengths in the lower 700nm region. After a lengthy search, he found that Extreme CCTV of Vancouver, Canada, manufactured illuminators at 730nm.

"It's hard to believe that people are still satisfied with surveillance cameras that don't work at night," Downs marveled. "Once I installed Extreme's illuminators, the PTZ cameras produced fantastic pictures even in the middle of the night."

Sempra Energy of San Diego is one of P.A.C.E.'s clients. Sempra is an international energy company responsible for electricity generation, gas storage and transmission and distribution of gas and electricity through two wholly-owned utility companies in California.

"Security has always been important in our business, but since 9/11 security has been stepped up," declared Gary Stephens, security manager for Sempra Energy's corporate security and emergency preparedness. "Since many of our assets are part of the national critical infrastructure, we must comply with a number of federal regulations.

"Being able to see at night is important," Stephens pointed out. "We have built a system that enables us to monitor remote assets day or night. We have obtained successful prosecutions with the use of videos that we have taken of crimes that have occurred in the middle of the night."

The American Gas Association stated, "Gas utility companies monitor their systems 24/7. Always have, always will."

To help achieve this end, advances in security technology have made 24/7 surveillance a reality, so that the little blue flame underneath every gas hot water tank in the nation ignites right on schedule.