Softwares are used for preparing maps with the help of data collected through remote sensing and other methods of survey. These softwares are also used for incorporating details in the maps and analyzing them for various purposes. This system is known as GIS.

The surface features of the earth collected as spatial information and attributes can be analysed by GIS in various ways according to the requirements. The analytical capabilities of GIS are network analysis, buffer analysis and overlay analysis.

Overlay analysis : Overlay analysis used to identify the interrelationship of various surface features on earth and the changes they have undergone over a period of time. This analysis is helpful in understanding the changes in the area of crops, the changes in land use, etc. Suppose we have a map showing the paddy cultivation in Thrissur district in 2000. If we want to understand the changes in the area of paddy cultivation by the year 2015, all we have to do is overlay the corresponding map.

Buffer analysis : This is an analysis capability used for analysing the activities around a point feature or at a definite distance along a linear feature.

Network analysis 

Linear features such as roads, rivers and railway are subjected to network analysis. Using this, we can find the shortest route to reach a place, routes with less traffic, routes without toll and can identify petrol pumps, hospitals and hotels.

For Extra  Reading

A Peep into the History of Remote Sensing First phase : Before 1925

• During earlier times, photographs of Paris city were taken using cameras tied to domestic pigeons.
• Photographs taken in this manner did not have a precise continuation or control. 
• Afterwards, balloons began to be used. 
• In 1858 Gaspard Felix took a photograph of a place called Beaver in France using balloon.

Second phase : 1925 – 1945

• The use of aerial photographs for collecting information about the earth’s surface became more widespread. 
• Camera lenses were used effectively. 
• Advanced aircrafts began to be used. 
• Aerial photographs were used greatly in the second world war.

Third phase: 1945 – 1960

• Aerial photographs began to be used in various fields. 
• Such photographs were widely used for theme based studies.

Fourth phase : 1960 – 1972

• Satellite remote sensing was started. , 
• Earth observation from the outer space started.

Fifth phase : After 1972

• America successfully launched the Landsat series of satellites. 
• India successfully launched several satellites such as Cartosat, Resources at, and Oceans.

Institutions that use Remote Sensing in Kerala Various central and state departments in Kerala and many private companies make use of remote sensing technology.

• Kerala State Remote Sensing and Environment Centre (KSRSEC) 
• Centre for Earth Science Studies (CESS) 
• Centre for Water Resources Development and Management (CWRDM) 
• Kerala Forest Research Institute (KFRI) 
• Kerala State Land Use Board (KSLUB) 
• Geological Survey of India (GSI) 
• Central Ground Water Board (CGWB) 
• Central Marine Fisheries Research Institute (CMFRI)