What is the Relationship Between GIS and Remote Sensing?

Firstly what is a GIS?

GIS fully means Geographic Information System.

GIS is a tool that can accept, analyse and present geographic data.

Geographic data refers to any data that has location in it.

Location refers to Longitude and Latitude (and maybe altitude).

Secondly, what is remote sensing?

Remote sensing is the process of acquiring and interpreting geographic data without physical contact.

This usually involves the use of satellites and drones to capture images after which specialized software is used to process and interprete these images.

Discussion

Based on the above, remote sensing can be seen as fuel for GIS. It provides data which we use a GIS (Geographic Information System) to analyse.

Remotely sensed images are only one of many types of data that a GIS can work with. A GIS can analyse spreadsheet data, it can analyse vector data and many others. That said, remotely sensed data is an invaluable source of data in GIS.

Take for instance, DEM (digital elevation model) tiles from were acquired through remote sensing. But you use a GIS (such as QGIS or ARCGIS ) to analyse it and get results which could be drainage basin delineation, topographic wetness index etc.

Important Points to Set Straight

Due to the fact that there are specialized GIS software for processing satellite images and the process has a lot of technicalities, many people think remote sensing is another field entirely.

Many times, people use the term remote sensing as a synonym for image processing. If what they mean by Image processing is preprocessing then they may be right. Preprocessing refers to making satellite images useable in GIS software. It involves restoring the image and correcting distortions caused the atmosphere on light rays.

But if what they mean by Image processing is extraction of useful information from remotely sensed data then this isn’t correct. This is because extracting useful information from remotely sensed data is done with a GIS.

In conclusion

Remote sensing provides data for GIS. It isn’t a subset of GIS. Rather they are independent but related fields.

Also, both fields do overlap in the stage of image processing.

Thanks for reading.

About Nasiru: He is a GIS Analyst, Cartographer and CEO at GeoAfrikana Spatial Solutions. He also finds time to write articles and be a GIS tutor. His mission. “To provide cutting-edge geospatial services for researchers, businesses and governments”.