Hyperpectral Imaging Research Paper

Hyperspectral Imaging
“If a picture is worth 1000 words, a Hyperspectral image is worth almost 1000 pictures.”
Dr. John P Ferguson
Hyperspectral imagining by definition means obtaining the spectrum for each pixel in the image of a scene, with the purpose of finding objects, identifying materials, or detecting processes. In more scientific terms, imaging spectroscopy (another terminology for Hyperspectral imaging) measures the spectral signatures hence allows it to measure the chemical composition of all features inside the sensor’s field of view. In simpler terms Hyperspectral imaging allows the identification of certain materials and/or elements from a specific image using both spatial and spectral information from the materials within a

In contrast to multispectral imaging, which can locate oil slicks by their distinctive color on ocean water, hyperspectral imaging allows a quantitative assessment of the amount of oil present. There are also many military applications of hyperspectral imaging. The high spectral resolution of hyperspectral sensors allows one to discriminate not only camouflage from background clutter, but different types of camouflage. Note the common spectral feature of two types of camouflage. They all "mimic" the red edge of vegetation, so they would all appear to blend in with background vegetation if they were imaged using conventional NIR/Red/Green multispectral imaging systems. However, hyperspectral imaging systems with expanded spectral coverage in addition to higher spectral resolution can differentiate the different types of camouflage, especially when examined in the SWIR portion of the spectrum. The SWIR bands also allow the discrimination between the two types of camouflage and the background vegetation. every feature within a given scene has unique spectral properties due

The concept of Hyperspectral imaging is designed to collect information as a set of images where each image represents a narrow wavelength range of the electromagnetic spectrum, this is known as the spectral band. The main idea is to combine these images in order to form a three dimensional (x, y, ʎ) Hyperspectral data cube which is processed and analyzed. X and Y represent spatial dimensions of the scene and the ʎ represents the spectral dimension made up of a range of wavelengths. This spectral dimension is a plot of wavelength and reflectance which is used to identify and understand a particular feature within the scene and hence the “fingerprints” of the materials are obtained and we are able to identify materials in the scene. Obtaining a Hyperspectral image can be tackled by any overhead method from airborne methods to space based techniques, the use of a particular grating will help in the dispersion of the spectrum.
There are four methods for the Hyperspectral sensors to create the Hyperspectral cube, Spatial scanning, Spectral scanning, Snapshot imaging and Spatio-spectral scanning. The choice of a specific technique depends on many factors from the specific application to each methods advantages and