Hi,
I am going to explain georeferencing in simple terms.
Sounds fun!!
What is georeferencing?
Lets say that you are working on this archaeological site called "A". You start by researching, reading books, reports watching videos. Now you may come across maps made for site "A". You identity features such as fortwall, moat, waterbodies and built heritage. Some of the features may still exist on ground while some may be in dilapidated condition or completely overgrown by land use change. Now this old map of "A" is an important information, it holds clue to the landscape. To use your clue effectively you need to assign coordinates to it. What you have now is a scan copy of a map and you would like to bring it to GIS environment. For which you need to give the scan copy(features) the same coordinates as on ground and this my friend is georeferencing.
What you can georeference?
Ok, so I have many maps/plans of site "A". Can I georeference all. No you can't. You can only georeference map with scale. In your research you will come across maps that are actually drawings of the landscape. One example of such drawings are by Francis Buchanan. He draws a rough sketch of Nalanda.
To summarize: I have come across many maps. You can georeference a map with accuracy which has a scale but you cant georeference a plan
What you can't georeference?
You can't georeference plans. For example plan of Patna.
