Here is a collection of all of the tethered aerostats for which I can find a reference.

These 'blimps' usually carry radar and are used to monitor airspaces and borders. In the US and Caribbean they are primarily used by the DEA and Customs.



More info here .

Some of these have been found by others.

Thanks to EdLizard, goearth4321, douggie, darick, Hill, Bill13508, drew10dall, webnut2000, coyote1982.