Spectral imaging datasets from Space
Let’s take a deeper look at how spectral remote sensing works.
The light spectrum is formed of multiple bands with varying frequency and wavelength (which are inversely proportional) ranging from Gamma to Radio waves. Whenever rays of light fall on an object, depending on its physical and chemical structure, a portion of the light is reflected, absorbed and transmitted through this object.
Different objects reflect different extents of light. We use sensors called spectroscopes to capture this reflected light to form a unique pattern that allows us to map the object
Multiple bands of the spectrum can be used for detecting different patterns and properties of objects.
For example, plants reflect a large portion of the Near Infrared rays (Band-4). Near infrared-based remote sensing allows us to draw up the vegetation cover over an area or region. Similarly, Short Wave Infrared (Band-7) is reflected by soil and bedrock. Typically, a combination of bands is used to illuminate the desired data/message. Multispectral remote sensing uses a combination of 3 to 10 bands while Hyperspectral imaging uses a continuum of spectral bands (hence can have over 100s or 1000s of bands).
As new-age #space companies come up — they are building technologies to provide data based on different bands and hence catering to different use cases. Capturing data, transmitting and then processing to provide insights and actionable intelligence across use cases and industries is contributing to the growing remote sensing market.
