July 31, 2012
By Al Herum
Inside a developing technology that's becoming more and more affordable.
Onboard infrared cameras capable of pan, tilt, and zoom hit the market a few years ago; these units displayed crisp and clear images on your multifunction display (MFD). The cost of this technology was high, even if you already owned a compatible network MFD.
The latest night vision technology takes the whole package including the high resolution infrared sensor, display screen, zoom capabilities and puts it all together in a compact scope with rechargeable batteries.
FLIR Systems Inc., a producer of thermal imaging gear for military, industry and marine concerns recently released two new models of its handheld infrared night vision camera for marine users. The First Mate MS series cameras are identical in external appearance. Both feature a compact design that fits easily in hand and weighs in at a mere 12-ounces. Top mounted pushbutton controls make it easy to turn the unit on or off and choose a background palette to your liking. You can select an easy on the eyes marine red background, or go with white hot, which shows warmer objects in white or grey. Black hot looks the most like a black and white photograph and shows warmer objects in dark greys or black. The case is ruggedly constructed for water resistance and able to operate in extreme temperatures. A weather protected USB port lets you both charge the internal battery and update software. You can expect about 5 hours of continuous use from a fully charged battery.
What the First Mate MS reveals is not magnified light, but rather reflected or object-generated heat. The day's solar energy leaves a lasting profile of this marina, long after dark.
The basic model, MS 224, features 240 x 180 thermal detector with freeze frame capability. A single press of a top mounted pushbutton will lock the last screen view for closer examination. In actual operation you can expect the MS 224 to detect a person at a range of about 1000 feet while something like a small boat will be visible at about a half a mile distant. Keep in mind this will be in complete darkness where nothing is visible with the naked eye or even with binoculars.
The upgraded version, the MS 324, has a higher resolution thermal detector (320 x 240) and a 2x zoom feature that replaces the MS 224 freeze frame—again, a single toggle of a top mounted button switches between normal and zoom mode. Because of the higher resolution thermal detector in the MS 324 it will pick up a person sized object at over a quarter mile away and a small boat at ranges of up to three quarters of a mile. Even an object as small as a person floating in the water where only their head and shoulders are above the water's surface should be detected in at over 100 yards in total darkness with the FLIR First Mate MS 324.
Either of these handheld thermal cameras should be a boon to the mariner venturing out in darkness. They will help you avoid hazards as well as act as a potential safely aid should a member of your party go over the side.
Infrared Basics
The image displayed inside the First Mate may look like an old B & W TV image—it's not. Infrared devices like the First Mate are radically different in that they use radiated thermal energy, or heat, to create an image, instead of visible light. The full electromagnetic spectrum is made up of everything from gamma rays to radio waves and contains only a very small visible light spectrum.
The only difference between these forms of energy is wavelength. Infrared energy has a slightly longer wavelength than visible light so an infrared imaging device sees differences in the heat energy from the objects in its field of view. If everything in the frame were exactly the same temperature, no contrast would exist so no image would be produced. In the real world, certain things create heat, so you'd see a clear and distinct image even in total darkness.
Two types of objects can be clearly seen by thermal imaging systems, those that reflect heat and those that generate their own heat. Heat energy transferred to objects by sun's energy during daylight hours will stay in the object for some time. That is why things like channel markers, floating debris, docks, or shoreline vegetation can be distinctly visible when viewed with the First Mate after dark. Heat generating objects like people, outboard engines, or electrical equipment will always present a noticeable heat signature and show up well on a thermal imaging device like the First Mate.
FS
