Satellite Image Processing

An image is worth of thousand words which conveys information about an object. Satellite imageries are imageries acquired by satellite at regular intervals and used to observe or forecast different parameters of Earth surface. A satellite image processing is defined as the interpretation and analyzing of remotely sensed data about Earth surface parameters to observe its nature (Figure 1).

Many image processing tools have been developed in order to interpret the satellite imagery and extract as much information as possible. Satellite imageries provide various advantages e.g. inexpensive large area coverage, digital format, geometrical accuracy and 3D visuals etc. Satellite imageries are used in many applications such as intelligence, forestry, meteorology, geology, smart city planning, warfare etc. These satellites are operated by governments or private agencies throughout the world.

Figure 1. An example of Satellite imagery to classify the Earth surface parameters based on Digital Number

In visual interpretation of satellite imageries, an assortment of imagery features needs to be considered such as color, texture, size, shape, pattern, context, and greyscale in case of panchromatic images. Figure 2 represent a brief overview of acquiring satellite imagery in which radiation reflected from the Earth surface is collected by sensing system in electromagnetic spectrum and at last, data products are available to the user for interpretation or analysis.

Figure 2. Satellite Image Processing

Latest trends in satellite imagery sensing involves acquiring information in multispectral or hyperspectral. A multispectral imagery capture image at specific frequencies across electromagnetic spectrum such as visible region, infrared region, thermal region etc. Spectral imaging allows the extraction of enhanced or additional information where human eye fails to capture. Active research and analysis in applications of satellite based image processing is becoming increasingly important to reveal some new information and assist in solving specific problems. The future image processing applications of satellite based imaging ranges from planetary exploration to surveillance applications. Research activities carried out based on satellite imagery provide a rapid way to obtain up-to-date information on the impacts of natural calamities like landslides, avalanches, flood flashes etc and also help in study other parameters of Earth’s surface and atmosphere concerning the conservation and management of resources & environment and promises sustainable growth.

By - Sartajvir Singh Dhillon - Assistant Professor, ECE Chitkara University H.P.