Laser Imaging Video Camera: Sees Through Smoke and Saves Lives
Laser imaging saves lives. Researchers developed laser-imaging video camera technology over a decade ago, not for security purposes but to enable firefighters and other first responders to see through smoke and flames. This technology has since evolved for use by the Navy and has ultimately found applications in several other fields.
The device has generated excitement about its applications, particularly its ability to increase aircraft visibility under adverse conditions. This is due to its ability to penetrate nearly all visual obscurants, including a blaze.
How Laser Imaging Saves Lives and Works
Laser Imaging Video Camera helps solve visibility issues pilots face. The laser imaging device works by directing fast pulses of near-infrared (NIR) laser light toward an object, then opening the camera aperture, or gate, timed to capture the laser pulses reflected from the target object.
Light travels at about one foot per nanosecond (ns, or 10^-9 seconds), so the camera might emit a 10-ns pulse of light, then wait about 50 ns before opening the gate. In the interval, the light will pass through the obscurant. The light bounces off objects about 25 feet away, is partially absorbed, and then returns to the camera.
The human eye can’t see wavelengths shorter than 300 nm (violet) or longer than 700 nm (red). We refer to wavelengths longer than 700 nm as infrared, and those near 700 nm as near-infrared. Recall that the longer the wavelength, the lower the energy, hence the prefix infra indicating below, or a lower energy.
Turning on the Camera: Laser Imaging Video Camera Saves Lives
When the camera is turned on, all near-term reflected light disappears, and workers are not blinded. The laser light scatters less than normal white light, partly by adjusting how long the gate waits to open. Workers trained on the camera can reach objects at different distances, up to a few miles. A closer object’s shadow can also make it identifiable. Something near the camera would appear as a silhouette against light reflected from objects farther away. The camera can see through fire because it only catches a few nanoseconds of light from the blaze. Not much compared to the concentrated laser light reflected from the object behind it.
Another way to see through obscurants, such as smoke, is to use a thermal imager. For example, it can see through the smoke if it’s cold. However, the technology doesn’t perform well in fog because water absorbs heat or infrared light. A thermal imager also cannot penetrate glass. No other system out there can see through a flame sheet. The device not only presented an elegant solution to a difficult problem, but also proved effective. The superior performance allows laser imaging to save lives.
Technology Transfer
However, the idea may seem relatively simple; the hardware to make it work is a technological challenge. Under the first two Small Business Innovation Research (SBIR) grants given by the US government, the researchers developed and refined a prototype. A working prototype requires developing the hardware, ensuring everything works, and getting all the timings right. Extensive tests were conducted to determine which surfaces reflect best under various conditions. Commercializing the device for ground applications, then using the income to continue developing the technology until it is small enough for use on airplanes, is the pathway to a new application. A third SBIR with Langley AFB funded further testing in 2012. https://www.glewengineering.com/global-fire-detection-sensors-in-space/
Perimeter security constitutes another potential application. The camera is triggered by a trip-wire-like laser, which then automatically turns to face the point where the perimeter was breached. Adding another option, on a track for added mobility. Neither the triggering laser nor the camera’s laser light is visible to the human eye. Based on our interactions with laser imaging and some of their early SBIR technology demonstrations, this generates excitement about the possibilities for this camera..
Refining Technology: Laser Imaging Video Camera
Researchers and developers have already shown interest in refining the technology for use in aviation and a host of other applications. They customize each system depending on the distance to the perimeter and other factors.
When the camera turns on, all that near-term reflected light disappears. Getting rid of the near-term scattering so that people can see. The laser light also scatters less than normal white light. By adjusting the time the gate waits before opening, people trained the camera on objects at different distances. It can reach up to a couple of miles. A closer object’s shadow can also make it identifiable, he explains. Something near the camera would appear as a silhouette against light reflected from objects farther away. The camera can see through fire because it only catches a few nanoseconds of light from the blaze. Which isn’t much compared to the concentrated laser light reflected from the object behind it.
Therefore, they need other ways to look through smoke and other obscurants. For example, a thermal imager can see through cold smoke, but it struggles with fog because water absorbs heat. A thermal imager also cannot penetrate glass. There is no other system out there that can see through a flame sheet. Not only did the device built with the Navy present an elegant solution to a difficult problem, but it also showed that laser imaging can save lives. https://www.glewengineering.com/global-fire-detection-sensors-in-space/
BENEFITS: Laser Imaging Video Camera Saves Lives
We are still looking forward to the day when the technology will help firefighters blinded by smoke and flames and help with perimeter security for first responders. Also, desert outposts need security systems that function in sandstorms. Further applications include nuclear power plants, facilities on foggy lakes, and the security of the US border. Laser imaging technology could also find applications in accident prevention for police and emergency vehicles. Laser imaging can save lives. https://www.glewengineering.com/thermal-analysis-devices-just-got-more-affordable/
Other Enhancements
One enhancement to infrared laser imaging is a synergistic partnership with an acoustics company to incorporate “localized acoustics” into the system. Such a system would be capable of pinpointing a sound at distances of up to 600 meters. Then, First Responders would know the status of remote scenarios and could say, “Please stop what you’re doing,” or “We can see you,” or whatever is appropriate to the situation without having to engage at close quarters. Low visibility is not always an issue; Laser imaging is considered a supplement to a system that includes other infrared vision and regular cameras. Envisioning applications not only in perimeter security, but also enhancing safety and efficiency in aviation and shipping, where vessels navigate in and out of foggy harbors. Truckers could avoid hazards, prevent accidents, and avoid pileups in storms and fog.
Read more about Laser Imaging Technology: https://spinoff.nasa.gov/Spinoff2015/ps_5.html