Hyperspectral Imaging

Hyperspectral Imaging

A 21st Century Tool for Resource Management

A New Way to Look at the World

A stretch of desert, an expanse of sea, a blanket of forest, a checkerboard of crops. Familiar vistas: scenic, but nothing out of the ordinary. Unless you know how to look.

With the right tool — a Northrop Grumman hyperspectral imager — detailed pictures emerge: a vehicle hidden by camouflage, an area teeming with fish food, trees growing at different rates, fertile land under-utilized.

By seeing what cannot be seen by the human eye, a hyperspectral imaging system gives resource managers — front-line commanders, farmers, urban planners, foresters, environmental analysts — a powerful tool to help classify features, measure productivity/yield and identify trends.

Bringing to Light

All objects — soil, water, trees, vegetation, structures, metals, paints, fabrics — create a unique spectral fingerprint. A sensor determines these fingerprints by measuring reflected light, most of which registers in wavelengths, or bands, invisible to humans.

Northrop Grumman's state-of-the-art hyperspectral imaging systems operate across up to 220 wavelengths to paint precise portraits of this hidden world. Where a standard sensor with fewer than 10 bands is capable only of differentiating between gross classes of vegetation, a hyperspectral imager can discriminate a maple from an oak, wheat from alfalfa, and is sensitive enough to separate healthy from unhealthy growth.

Images in Action

These finely tuned sensors are coupled with powerful processing algorithms to provide a tool that has as many applications as there are spectral bands. With hyperspectral imaging, a camouflaged missile is transformed into a landmark, a fleet sets a course for fertile fishing beds, tree growth patterns lead to harvesting efficiencies, a farmer rotates crops.

At Any Altitude

Hyperion, NASA's first hyperspectral imager to become operational on-orbit, was launched in November, 2000. Built and delivered by Northrop Grumman, the 220-band instrument is setting the standard for orbiting imagers, providing a more than thirty-fold increase over multispectral capability now aloft. While spaceborne hyperspectral sensors provide pre-planned overflights for large-scale sensing operations, instruments flown aboard fixed wing aircraft offer flexible scheduling for local surveys. Northrop Grumman currently performs airborne data collection with the TRWIS III with image spatial resolutions spanning from less than 1 meter to more than 11 meters, with spectral coverage from 380 to 2450 nm. Spectral resolution is 5.25 nm in the visible/near infrared (380 - 1000 nm) and 6.25 in the short wave infrared (1000 - 2450 nm). Data is digitized to 12 bits, offering superb dynamic range in the video data.