Rising to the Challenge – Creating the RFeye SenS Remote Wideband I/Q Recorder

This was the problem facing an existing CRFS national defense customer. They had already deployed an RFeye Node network along the contested border area, which gave them the ability to accurately monitor the spectrum and geolocate RF transmissions. What they lacked was the ability to record and analyze these signals in high fidelity, across a wide frequency range, and over a sustained period to build up a pattern of life. In essence, they required a detailed picture of local EM activity to identify and classify difficult signals of interest (such as frequency hoppers and short bursts). From this, they could create a library of signals, which could then be distributed to other departments and agencies across military and government.

The Missing Link

To assist the client, we reviewed the capabilities of the RFeye Node and RFeye SenS Portable and found that we were missing a link. The RFeye Nodes are rugged, deployable, and can stream/record I/Q data, but only at a limited instantaneous bandwidth (IBW) and for relatively short durations.  The RFeye SenS Portable, our lightweight, portable I/Q recorder, can record a higher I/Q IBW of 100MHz, but is not a rugged device and is designed primarily for manned operator use rather than continuous remote deployment.  The customer wanted to operate in all weather conditions potentially 24 hours, 7 days a week. Additionally, the built-in data storage is sufficient for a day or two’s mission rather than ongoing data collection. Lastly, there was a physical data security concern which meant that any recording media should be secured.

And so, the RFeye SenS Remote was Born

The challenge to the CRFS engineering team was to create a rugged, long duration I/Q recorder, with outstanding hi-fidelity, a wide IBW with expandable and secure data storage.  The result was the SenS Remote.

The SenS Remote combines all the features and functionality of the RFeye Node with the recording capabilities of the SenS Portable in an outdoor ruggedized form. It enables secure recording to take place in fixed, unmanned locations. A remote RF receiver head and antennas are mounted high up on a mast, tower or roof top and I/Q data is streamed via armored fiber optic cable to COTS rack-mounted processors and storage media. The server rack is installed in a secure outdoor enclosure or inside a building, ensuring no sensitive data is retained on the receiver head.

Two Operation Modes, One Solution

The SenS Remote can operate as part of a normal RFeye network and will perform all the functions of a Node, including scans, sweeps, detections, geolocations and more. In its SenS mode, it streams full-rate I/Q data at 100MHz IBW to a COTS storage rack. A capability that enables the recording of RF signals for days, including highly sporadic but critical signals. Recording media can hot swapped, allowing the SenS Remote to record spectrum data indefinitely.