The Providence Journal has a fascinating piece on the little known story of domestic radio surveillance during WWII. The Intelligence Division of the FCC selected several sites in the U.S. to set up monitoring stations to listen for enemy spies. A wartime short movie featured the radio surveillance effort. The Chopmist Hill Station on a 183 acre site atop a 730 ft hill in Scituate, Rhode Island proved to be one of the most successful of these stations. Among the station’s accomplishments:
- Detecting Japanese fire balloon transmissions so they could be intercepted and shot down by fighters.
- Monitoring U-Boat transmissions. In one case an intercept from the station led the Queen Mary and her 14,000 troops to be diverted from harms way.
- Monitoring German domestic weather updates that could not be heard in Britain.
- Providing radio-navigation assistance to lost planes along the eastern seaboard.
- Obtaining intercepts from Rommel’s Army in North Africa.
The ideal location for an HF band receiving station is on elevated terrain overlooking the ocean. Signals propagate well over the conductive sea water, and sources of man-made noise are much reduced. Ham radio operator KB1SJ has a Chopmist Hill Station description for the more technically inclined. And Rhode Island Radio has further details including some great pictures. (H/T Instapundit who has some excellent comments as well).