Question – Discussing the benefits and applications of remote sensing satellites in various fields, throw light on the various remote sensing satellites launched by India, and the various projects facilitated through them. – 23 February 2022
Answer – Remote sensing is the acquisition of information about an object from a distance without physically coming into contact with the object. It is based on the principle that different objects have different radiation characteristics. It is useful for monitoring and evaluation of natural resources etc. through analysis of data obtained by observation from remote platform. The characteristics of an object can be determined using electromagnetic radiation reflected or emitted from the object. Actually every object has a unique and different characteristic of reflection or emission. Thus, remote sensing is a technique of detecting and perceiving an object through reflection or emission.
Advantages of remote sensing satellites
- The advantages of the satellite based remote sensing are its wide coverage, saving in time and tremendous cost effectiveness over other techniques.
- Large area coverage enabling regional survey of variety of themes and identification of large features.
- Repetitive coverage, allowing monitoring of dynamic themes like water, agriculture, etc.
- Data acquisition at multiple heights
- Data acquisition over inaccessible areas
India’s remote sensing satellites
- RESOURCESAT-2A: A follow-up to the missions of RESOURCESAT-1 and RESOURCESAT-2 which were launched in October, 2003 and April, 2011 respectively. The new satellite provides services similar to other RESOURCESAT missions. It will provide regular micro and macro information on farm land and crop volume, forest, mineral deposits, coastal information, rural, and urban sprawl, underground and water bodies, along with helping in disaster management.
- Cartosat: The Cartosat is a series of Indian optical earth observation satellites built and operated by the Indian Space Research Organisation (ISRO). The Cartosat series is a part of the Indian Remote Sensing Program. They are used for Earth’s resource management, defence services and monitoring.
- Oceansat-2: Oceansat-2 is the second Indian satellite built primarily for ocean applications. It was a part of the Indian Remote Sensing Programme satellite series. Oceansat-2 is an Indian satellite designed to provide service continuity for operational users of the Ocean Colour Monitor (OCM) instrument on Oceansat-1.
- RISAT-2B: RISAT-2BR1 is a radar imaging earth observation satellite. This satellite will provide services in the fields of agriculture, forestry and disaster management.
- SARAL Satellite: An Indo-French joint mission for oceanographic studies. Designed for altitude measurements for simple ocean movement and ocean surface elevation studies.
Scientists use infrared images to determine vegetation conditions, survey temperature changes in water bodies, locate damage in underground pipelines, and map certain geographic features above and below ground. Images from satellites are used in the search for mineral and petroleum deposits. Therefore, remote sensing technology and remote sensing satellites have many applications and help in the social, political, economic, environmental development of the country.
