Question

Why are remote sensing satellite considered as an effective monitoring tool?

Answer 1

Remote sensing satellites are considered as an effective monitoring tool for the following reasons:

1. Data coverage: It allows data collection in remote lands, ocean and ice area where humans find it difficult to reach due to difficulty in accessibility or political reasons. Data collection is greatly improved and complete when compared to conventional methods.
2. Homogeneity: Information collected by a satellite system provides a special consistent data. This is directly contrasted to the several methods used in ground data collection. It provides a spatial continuity as compared to the point or small area sample data commonly found in metrological, oceanography and geology. 
3. Computer processing: Satellite Remote Sensing produces digital data which are in a form suitable for direct computer processing. It reduces the work of man and saves the time of manual calculation.
4. Frequency of data collection: Frequent data collection is possible with the use of Remote Sensing Satellites. The frequency of data collection depends on the time taken by the satellite to orbit the earth. The Geostationary weather satellite scans the earth every thirty minutes, polar orbiting weather satellite collect data twice per day for each part of the earth and land satellite passes over the same point on the earth every sixteenth day.
5. Less time based: Remote Sensing Satellites cover a large area at a very high speed which can detect the variation in environment with great precision. For example, the Landsat thematic Mapper images a scene of 170 km x 185 km in 25.87 sec.
6. Complementarity: Measurements or information gathered from satellite are complementary to conventional observation. It removes the need for ground check at huge cost and time.
7. Low cost means: The initial cost of building and sending the satellite to space is huge and is borne by the Government. But later it is an advantage as it reduces the cost of manpower requirement for survey, cost of transport, fooding and lodging for the survey team. The computer compatibility of Remote Sensing Satellite not only reduces the time but also the cost of manual computing.