Hyperspectral Systems Increase Imaging Capabilities
- Friday, 01 January 2010
While the human eye can see a range of phenomena in the world, there is a larger range that it cannot see. Without the aid of technology, people are limited to seeing wavelengths of visible light, a tiny range within the electromagnetic spectrum. Hyperspectral imaging, however, allows people to get a glimpse at how objects look in the ultraviolet (UV) and infrared wavelengths—the ranges on either side of visible light on the spectrum.
Hyperspectral imaging is the process of scanning and displaying an image within a section of the electromagnetic spectrum. To create an image the eye can see, the energy levels of a target are color-coded and then mapped in layers. This set of images provides specific information about the way an object transmits, reflects, or absorbs energy in various wavelengths.
Using this procedure, the unique spectral
characteristics of an object can be revealed by plotting its energy
levels at specific wavelengths on a line graph. This creates a unique
curve, or signature. This signature can reveal valuable information
otherwise undetectable by the human eye, such as fingerprints or
contamination of groundwater
Originally, NASA used multispectral imaging for extensive mapping and remote sensing of the Earth’s surface. In 1972, NASA launched the Earth Resources Technology Satellite, later called Landsat 1. It had the world’s first Earth observation satellite sensor—a multispectral scanner—that provided information about the Earth’s surface in the visible and near-infrared regions. Like hyperspectral imaging, multispectral imaging records measurements of reflected energy. However, multispectral imaging consists of just a few measurements, while hyperspectral imaging consists of hundreds to thousands of measurements for every pixel in the scene.
In 1983, NASA started developing hyperspectral systems at the Jet Propulsion Laboratory. The first system, the Airborne Imaging Spectrometer, led to the development of the powerful Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) that is still in use today. AVIRIS is connected to the outside of aircraft and is used to gather information to identify, measure, and monitor the environment and climate change. In 2001, NASA launched the first on-orbit hyperspectral imager, Hyperion, aboard the Earth Observing-1 spacecraft.
Based on the hyperspectral imaging sensors used in Earth observation satellites, NASA engineers from Stennis Space Center and researchers from the Institute for Technology Development (ITD) collaborated on a new design that was smaller and incorporated a scanner that required no relative movement between the target and the sensor. ITD obtained a patent for the technology and then licensed it to a new company called Photon Industries Inc. In 2005, Lextel Intelligence Systems LLC, of Jackson, Mississippi, purchased the company and its NASA-derived technology (Spinoff 2007).
Without the technical expertise to market the product, the company’s license for the scanner returned to ITD. In 2008, Themis Vision Systems LLC, of Richmond, Virginia, obtained an exclusive license for the technology. The CEO of Themis, Mark Allen Lanoue, was one of the original researchers on the staff that developed the device at ITD and saw the potential for the technology. In 2005, Lanoue, several colleagues, and the technology were inducted into the Space Technology Hall of Fame, created by the Space Foundation, in cooperation with NASA, to increase public awareness of the benefits that result from space exploration programs and to encourage further innovation.