I'm pretty new to Arcgis software and going to create map. I have some points which should be shown on the map( there are temperatures of cites). So, I need to create a map in arcgis. I guess! What I have is a jpeg file of the area. Is there any way to do that?
You can georeference a JPG image if you can identify parts of the image in another basemap or geo-referenced dataset of any kind. Get the georeferencing toolbar from the Customize Menu.
When you bring the image in (add it like you would any other data) it won't match anything spatially so you will need to match areas in the JPEG with areas in your basemap or other data by adding control points.
Click the add control points tool and click on a point (that you can identify) on the JPEG and then click the corresponding point on your basemap. Then repeat that process (you need 4 I believe but you could benefit from having more). Check the links table after you have a number of them and you may want to delete a few that have bad error values. You can have it auto-update the display so after a few links going back and forth will be easier.
Then when you are happy with the result, on the Georeference menu select Rectify and save your result. Hope that helps.
You can add your jpg in ArcGIS like any other image (add data). Now, for making a map, you'll need a georeferenced image. There are two main methods:
- if you know (from metadata) where your image should be, create a world file with .jgw extension (e.g. using notepad) and the same name as your image. The structure of the file is
rotation about Y axis
rotation about X axis
- use the georeferencing toolbar in argis, adding a basemap (e.g. open street map) to find relative ground control point that will serve for georeferencing.
Assuming you know the coordinates of your data points you should be able to write it all up in an excel sheet. using the following column names:
The Excel sheet can then be used to plot points using ArcGIS or QGIS (the pen source equivalent of ArcGIS).For the ArcGIS software ESRI has made a fairly straightforward technical article. It shows how an excel sheet can be imported and plotted.
The result of the above process is a shapefile with the spatial object, places and temperatures. Give the points a style which you feel reflect the temperature values in a good way. Then proceed to add a background map using Add basemap from the Add data item in the File menu.
This procedure will help you make an actual map rather than georeferencing an existing map (the jpeg image). It will also allow for future adjustments and analysis.