New infrared camera brings pollution into focus

Researchers at NASA’s Jet Propulsion Laboratory have created the world’s first four-band infrared focal camera that will allow them to ‘see’ details in infrared that were previously unachievable.

Researchers at NASA’s Jet Propulsion Laboratory (JPL), California, have created the world’s first four-band infrared focal camera that will allow them to ‘see’ details in infrared that were unachievable with previous technology.

According to JPL, the detail provided by the new technology will give researchers a wider view in the field of remote sensing for pollution detection, weather prediction and other atmospheric and geological applications on Earth.

Although a part of the electromagnetic spectrum, human eyes cannot detect infrared light. It is, essentially, heat that is emitted from every object whose temperature is above absolute zero (about -273 degrees Celsius or -460 degrees Fahrenheit).

‘This technology will revolutionise the way we develop new remote sensing instruments,’ said team leader Dr. Sarath Gunapala, senior research scientist at JPL. ‘One such example is the detection of smog. Smog contains a range of chemicals, which only appear in certain infrared ranges. The multi-band capacity of the camera array will allow researchers a full spectral view to identify them.’

The new four-band Quantum Well Infrared Photodetector camera can see up to 15.5 microns of a metre in the infrared. Its focal plane can be compared to the retina of an eye in that more nerve endings on a retina provide more detailed sight. Thus, adding more pixels to the bands increases the detail and information the camera can capture. Each band, or focal plane, measures 128 by 640 pixels.

The existing one-band technology Quantum Well Infrared Photodetector technology developed at JPL has been licensed for various commercial applications, including non-invasive detection of breast and skin cancers. The camera has also proven useful to firefighters and television news helicopter crews by allowing them to see forest fire hot spots through heavy smoke.

The camera has already flown over and imaged parts of Africa as part of an international project to study the environmental impact of vegetation burning and related ecological effects.

Ultimately, this detector will form the basis for a 64-band hyperspectral infrared-imaging instrument as part of a collaboration between JPL, NASA’s Goddard Space Flight Centre and the US Army Research Laboratory.