As a relatively active rover for satellite operations, I’m often looking to check whether a new location will be within my “VUCC circle” and be eligible to count for my home station VUCC certificate. Rule six of the ARRL’s VHF/UHF Century Club (VUCC) Award Rules states:
For VUCC awards on 50 through 1296 MHz and Satellite, all contacts must be made from locations no more than 200 km apart. For SHF awards, contacts must be made from a single location, defined as within a 300-meter diameter circle.
This means that I can use many operation positions, including those from different grids and parks from my Kansas State Parks POTA mission, and effectively double dip on these contacts as long as no two locations are more than 200km apart. Although it’s easy enough to manually measure distance between locations using the ruler tool on Google Maps, as your list of locations grows, that gets difficult. I decided to write a quick and dirty Python script that checks every combination of locations against one another to see if any are more than 200km apart.