Spirent Launches Multi-Frequency GNSS Record and Playback System

Photo: Spirent Communications

Spirent Communications’ new  SS6425 multi-frequency GNSS record and playback (RPS) test system provides RF recordings for more constellations (GPS, GLONASS, Galileo, BeiDou, QZSS), more frequencies (L1, L2, L5), wider bandwidth (30MHz) and more features than the company’s previous systems, to support a wide range of positioning and timing test applications.

The test system is self-contained and portable, enabling users to record and playback data in the field without the need for an additional PC or external power. With the GSS6425, it is simple to faithfully capture and replay complex signal conditions, such as urban environments, indoor spaces like airport terminals, and dense forests, Spirent said. Multiple environments can be brought into the lab and replayed in a repeatable and controlled manner, helping developers improve receiver and system performance.

“Customers have told us they want to record multi-GNSS signals simultaneously, for example GPS, GLONASS and BeiDou,” said Rahul Gupta, product manager for Spirent’s positioning division. “They have also told us that capture and playback of other data, such as inertial or vehicle CAN bus is needed. The GSS6425 enables all this in a very capable, yet easy-to-use and self-contained unit.”

Users can select and record three GNSS frequency bands at any one time, each with up to 30MHz bandwidth. If more than three concurrent channels are required, two GSS6425 units can be synchronized in a master and slave configuration. For example, survey-grade receiver developers can capture GPS L1, L2 and L5 signals, GLONASS L1 and L2, plus satellite-based augmentation system (SBAS) signals such as StarFire or OmniSTAR.

The GSS6425 is also capable of recording additional sources including inertial and dead reckoning sensor outputs and vehicle CAN bus data. Data can be time-stamped and stored in the GNSS data file, ensuring synchronized playback. The GSS6425 can also record the GPS receiver 1pps (pulse per second) output for synchronization purposes. These features are particularly useful in developing hybrid receivers such as for automotive and indoor positioning applications, Spirent said.

Key features include:

• Multiple constellations and frequencies
  • GPS, GLONASS, Galileo, Beidou, QZSS
  • L1, L2, L5
• Self-contained portable unit
• No PC or external drives required
• Control from front panel, webserver or scripts
• OCXO used on record and playback for frequency stability
• Internal 1TB hard drive with additional removable 1TB hard drive
• Synchronization of two units in master/slave configuration to support total of 6 frequencies
• Store asynchronous or synchronous external data at the same time as GNSS signals

Recorder features:

• Record any three RF grequencies simultaneously
• Internal battery (up to 1.5 hr) and vehicle DC power adapter
• 2-bit quantization
• Single-touch record
• Event markers

Playback features:

• Attenuation control per channel
• Browser control over network
• Multiple file playback
• Start at any point in a file
• Scripts allow inclusion in automatic test routines