Georeferencing is the process of assigning locations to geographical objects within a geographic frame of reference. It is fundamental to geospatial technologies in general, and geographic information system (GIS) in particular.
Following steps shall be undertaken for georeferencing in ArcMap.
Step 1: Go to Survey of India website – https://surveyofindia.gov.in/pages/state-maps and download desired map file.
(For instance, here Meghalaya state map has been taken.)
Step 2: Click on Add Data. Click on Connect to Folder icon. Choose the desired folder (where the map was saved in last step) and jpg file (downloaded map). Click on Add.
Output: The chosen file appears on the screen.
Step 3: To add coordinates (for projection): Right click on the screen and click on Data Frame Properties. A dialog box appears, choose Projected Coordinate Systems under Coordinate system tab. Choose UTM, WGS 1984, Northern Hemisphere and UTM Zone 46 N.
Step 4: Right click on the screen and click on General. Choose Degrees Minutes Seconds in Display under Units. Click OK.
Step 5: Take cross on the intersection and left click and then right click. Select Input DMS of Lon and Lat. Enter the values of Longitude and Latitude in degree minutes and seconds. Add four (this number may vary) such control points across four corners.
Output: Four control points appear on the map and the map is now georeferenced.
Step 6: Control points can be checked using View Link Table icon. The dialog box appears showing all the links and relative values. Specific points can also be deleted from here by selecting the particular ones.
Related
- Geographic Information System (GIS) in Urban Planning
- Who uses GIS Software – Organisations and Departments
- GIS Application in Urban Planning Projects
- Application of Geographic Information System (GIS) in Smart Cities
- 20 Differences between QGIS and ArcGIS
- Geospatial & GIS: What’s the difference
- GIS Softwares
