OTHR stands for Over The Horizon Radar, and ELINT stands for ELectronic INTelligence.
Why Orford Ness?
Several factors contributed to the fact that Orford Ness was home to at least 3 different intelligence gathering radar systems during the Cold War era. These factors were:
- Secure location. As a military research establishment on a shingle spit, Orford Ness has had restricted public access from the beginning, and with the establishment of the AWRE facility a separate secure area was established.
- Geographical situation. Being able to “look out” towards the USSR with an unobstructed path to the sea horizon was a very important factor. 1
- Radio quiet zone. Distant from major population centres, Orford Ness was located in a quiet radio environment. 2
- Ground conductivity. Maintaining a suitable earth potential in relation to the aerial systems is important for sensitive radio and radar installations. Steel mesh earth mats can (and were) installed but high ground conductivity is an important advantage. 1
Besides over-the -horizon radar, there were other radio experiments on Orford Ness. One specific example is the radio tracking of Sputnik I, which was carried out by an AWRE team in 1957. IRGON is researching this, as well as other mysterious aerials which were present on the Ness in the 1950s and 1960s.
References
1. Memorandum to I. Maddock from S.D. Abercrombie, Superintendent of Electronics Field Experiments, AWRE Aldermaston., reference 621.396.969.106/1, 1st October 1963 2. Echoes and Reflections, Keith Wood, Serendipity Press, 2004, p. 136.