US Navy AN/TPS-71 Relocatable Over-The-Horizon RADAR 8kHz | Signal Phantom

This video shows the 8kHz FMCW sample of the US Navy AN/TPS-71 Relocatable Over-The-Horizon RADAR (ROTHR) was initially contracted to the Raytheon Corporation in 1984 with subsequent contracts to upgrade and support growing program developments. The system is reported to operate from 5 to 28 MHz and can be seen using FMCW modulation at 4, 8, 16, 50 and 100 kHz bandwidths and 32, 64 and 128 pulse sweeps with various Pulse Repetition Frequency. Power is a combination of summing ten 20kW solid state P.A.’s (each consisting of four individual 5kW P.A.’s) for a total of ~200kW feed to the high/low range wire vertical log periodic arrays. It is extremely frequency agile and at times has a three pulse carrier into burst as seen in the video.
AN/TPS-71 uses a bistatic transmitting and receiving system with remote command and control via the main Operations Control Center providing both sea and air surveillance sectors called Dwell Information Regions.
The term “relocatable”, was used to describe the generators, transmitters and receivers. Receiver array has 372 dual monopole elements arranged in two rows nearly 2.6kM in length confirmed via satellite image. System also incorporates vertical incident sounding for propagation management.


Some interesting over-the-horizon forerunners were projects: US Naval Research Laboratory (NRL) MADRE; WARF; AN/FPS-95 (COBRA MIST); AN/FPS-112 and AN/FPS-118.
Signal received here in Fort Collins, Colorado by Northern Colorado Amateur / HAM Radio Operator Tyler Stampfli, KA0KA.