Lecture 2

Based on Number of Spectral Bands used 

Multispectral Remote Sensing: Bands (green, red, near infrared, shortwave infrared) of the multispectral sensors usually range between 3 and 10. IRS (Indian Remote Sensing) series satellites of India, Landsat of USA, and SPOT (Satellite Pour l’Observation de la Terre) satellite of France are well-known multispectral satellites. 

Hyperspectral Remote Sensing: Hyperspectral sensors have narrower and as many as 200 (or more) contiguous spectral bands. The numerous narrow bands of hyperspectral sensors provide a continuous spectral measurement across the entire electromagnetic spectrum and therefore are more sensitive to subtle variations in reflected energy. For example, multispectral imagery can be used to cropped areas, while hyperspectral imagery can be used to map crop types within the cropped fields. Contiguous high-resolution spectrometry provides a new dimension in mapping capability because of the potential for quantitative measurement of surface biogeochemistry. Hyperion of E0-1 and AVIRIS (Airborne Visible and Infrared Imaging Spectrometer) of NASA is hyperspectral remote sensors on satellite and airborne platforms respectively. 

          Out of all above listed remote sensing types, passive multispectral satellite remote sensing in optical and reflective infrared region is most commonly available and used worldwide.