7.5 Generate Google Earth Maps
Authors’ geographic locations in their publication records can be mapped to a geospatial map in KML. You can use Google Earth as the interface to explore the authors’ locations and links to their collaborators. You can also go to the original articles directly within Google Earth.
To generate the map file, you need to specify a data folder that contains bibliographic records in the Web of Science format (plain text), which is the same format for CiteSpace projects. This time we just need the data folder. A new folder will be automatically created under the data folder called kml. You will find the generated KML file in the kml folder when the geocoding process is completed.
Figure 1. The "Generate Google Earth Maps" function is under the Geographical menu.
Figure 2. Select the range of the years of publication to be included in the map and the folder that contains data files downloaded from the Web of Science (note the filenames should start with 'download').
Figure 3. A KML file is generated and saved in a compressed format kmz. You can use Google Earth to open the file.
The Google Earth map generator from CiteSpace needs to know the timespan you are interested, similar to the time slicing setup in the main interface of CiteSpace. Browse to the data folder of your data and click on the “Make Map” button. It may take a while for the process to complete.
Once the map is generated, you will see a Message notifying you where the map file is, which is in kmz format, i.e. a compressed KML file.
If you see some errors reported by the generator, you may check the error log file – geocoding_log_tab.txt – and see if you can make corrections in the data and repeat the process afterwards. The map is stored in the master-medium.kmz file if you use the default scale of medium.
If you have Google Earth installed on your computer, you can double click on the kmz file.
Figure 4. The KML file is shown in Google Earth.
Under the Places, you will see a list of years as layers. You can select or unselect these layers by checking or unchecking the checkbox in front of them so that you can control which years of data you want to see. Coauthored papers in more recent years are linked by lines in red, whereas older collaborations are shown in green or blue lines.
Figure 5. Publications by authors at the same location are shown as a list of DOI links.
You can drill down from a layer of a year to a location, then to a list of papers published by authors at that location. Each paper on the list is clickable. It will bring you to its full text via its DOI link. You need to have the right subscription to access papers in this way. Click on any of the papers on the list to explore its content.
Figure 6. The full text of a paper from the list at Washington DC. The same paper is also shown at the location of the first author, Santiago,Chile.
Figure 7. A coauthored paper is shown at each location of its coauthors.