RSR GNSS Transcoder

The revolutionary RSR GNSS Transcoder™ is based on VIAVI's next generation low-cost GPS Simulator technology. The RSR GNSS Transcoder allows retrofitting of any legacy GPS equipment to next-generation GNSS, SAASM, M-Code, INS, and other PVT/PNT sources. and can also be used as a general-purpose small GPS simulator for testing, manufacturing, qualification, spoofing, and jamming simulation. The RSR GNSS Transcoder is only 1.6 x 2.3 inches in size, does not require any external computer, consumes less than 1.1 W, can be mounted directly below a Rockwell Collins RSR SAASM Puck receiver, and offers optional CSAC holdover capability.

The output of the RSR GNSS Transcoder(tm) is a -120 dBm L1 GPS RF signal that looks to the legacy target receiver just like a standard live-sky GPS signal. The Transcoder takes NMEA or SCPI base-band Position, Velocity, and Time information, and converts this in milliseconds to a matching RF output. This allows receiving any modern GNSS system (GPS with SBAS, Galileo, Glonass, BeiDou, SAASM, M-code, etc etc) and converting this in real time using the integrated full-constellation GPS simulator into a legacy GPS RF signal that can be sent to any legacy GPS receiver. The system is thus retrofitted with the latest GNSS technology without having to change anything in the legacy system other than replacing the GPS antenna with the RSR GNSS Transcoder(tm). For added functionality and performance the Transcoder includes a real-time INS, as well as an optional CSAC atomic clock for exceptional holdover (GNSS-denied) operation.

The RSR GNSS Transcoder can be powered and controlled from a standard USB port, as well as from an optional vehicle/avionics power supply that allows operation anywhere from 7 V to 36 V. The unit has integral RS-232 ports for communicating to an external GNSS receiver or other NMEA source, an external 1PPS input allowing 5ns time-transfer accuracy to the RF signal, and a GPS L1 RF output connector with integrated antenna load for GPS receivers that require a DC antenna load to operate properly.

External GNSS receivers such as Rockwell SAASM receivers and uBlox GNSS receivers are automatically detected  and configured via the RS-232 port. The module itself can be monitored, programmed, controlled, and adjusted through the USB port via the new freeware SimCon application downloadable from our support web page, using GPSCon, or via any standard serial terminal.

Highlights

• Embedded NMEA Transcoding to L1 GPS in real-time
• Upgrade Legacy GPS to GNSS, SAASM, M-Code, INS
• Adds optional CSAC holdover capability
• 1.6 x 2.3 x 0.5 inches, 1.1 W
• Low-Cost General Purpose GPS Simulation
• GPS Spoofing and Jamming simulation
• USB, RS-232, interfaces
• 5 V USB, or 7 V to 36 V DC power
• Form, Fit, Function compatible to Rockwell Collins RSR SAASM Puck
• GPS Week Number Roll-over simulation or offsetting to bypass legacy GPS bugs
• Leapsecond simulation
• High-dynamics simulation
• 5 ns timing and sub 1 m positioning-accuracy typically

Applications

Typical applications would insert the Transcoder module and a user-selected GNSS front-end into a legacy antenna system.