Users of Google Earth Pro 6 can now measure buildings, calculate line-of-sight and visualise viewsheds.

Google Earth Pro allows users to view and style data in the same way as GIS files.

Earlier this month the Google Earth Pro Team released Google Earth 6, an improved version of its virtual globe software.

It includes thousands of new 3D building models, trees and better integration with Google Street View.

Google has also simplified the process of finding and accessing historic image sets, such as Warsaw in 1935 or London in 1945, which were introduced in Google Earth 5.

Google Earth 6 is available for free; Google Earth Pro, a version for professionals who need access to GIS data import capabilities and other advanced features, sells for USD 399 per user, with volume discounts.

Google also offers a version of Google Earth for enterprise customers.