GPS signal simulator with 16 channels and SBAS (WAAS, EGNOS) - GSG-55

The Pendulum GSG-55 is a GPS constellation simulator that expands on the set of features of the popular GSG-54, adding 16-channel simulation, SBAS simulation and white noise generation. These new features make the GSG-55 capable for in-line production testing, including navigational fix and position testing, for engineering and development of even more applications than the GSG-54.

Spectracom announced the Pendulum GSG-55 GPS receiver test instrument capable to simulate Satellite-Based Augmentation Systems (SBAS). Navigation systems that use SBAS can improve the accuracy and reliability provided by the GPS satellite signals alone, enabling critical applications such as aircraft navigation, and surveying and mapping. SBAS simulation (support for Europe’s EGNOS and North America’s WAAS) is a new feature in the GSG-55.

The GSG-55 user can configure scenarios on-the-fly without the need for external PC and pre-compilation phase. Via the front panel the user can swiftly modify parameters such as user position, time and specify output powers in carrier to noise ratio instead of absolute output power. Utilizing the white noise generation extends the usability and flexibility.

• Versatile 16-channel GPS signal generator with pre-configured test scenarios
• SBAS (WAAS, EGNOS) simulation
• Configurable multipath simulation
• White noise generator for receiver SNR testing
• Easy-to-use and intuitive
• Fully operational via front-panel
• Multiple interfaces for remote control
• Affordable and powerful GPS Simulators

12-channel GPS receivers are popular in GPS applications today, the GSG-55 16-channel simulator makes it possible to simulate all the channels those receivers can track. In addition other channels can be used for SBAS simulation of EGNOS or WAAS satellites.

GSG-55 is shipped with several multipath scenarios where the receivers’ response to an increased multipath environment can be analyzed. It also has a set of trajectories (static, circles, rectangular according to 3GPP TS 25.171) that allows the user to upload their own trajectories in NMEA standard format. The user can upload their own ephemeris data in standard RINEX format or re-use the default data for any time periods. GSG-55 can even automatically download historical RINEX, WAAS and EGNOS data from official ftp sites, as needed. GSG-55 has USB, GPIB as well as Ethernet interface, allowing remote control via network connection.

Besides the variety of built-in navigation/positioning tests, the GSG-55 is also suited for accurate testing of timing GPS-receivers. The GSG-55 can be equipped with an ultra-high-stability OCXO timebase for precision timing of the satellite data, or use external synchronization from a 10 MHz reference from e.g. a Cesium or Rubidium clock. A built-in 1-pps output, synchronized to the generated satellite data, allows comparison with the 1-pps signal from the timing receiver under test.

The GSG-55 is a perfect fit for a wide-variety of test cases including:

• Test of simulated movements (user trajectories).
• Test of receivers’ sensitivity to loss of satellites, multi-path, leap seconds and atmospheric conditions.
• Fast production test of connectivity and sensitivity (conducted or over-the-air).
• Production test of positioning receivers' accuracy.
• Test of timing receiver accuracy.
• Test of receivers’ dynamic range.
• Test of receivers' susceptibility for noise (SNR limit testing).

It is also able to generate white noise, making it possible to test receiver sensitivity under different signal-to-noise ratios. The GSG-55 builds on the popular Pendulum GSG-54 eight-channel simulator including accurate testing of GPS timing receivers and portability through its compact and lightweight bench-top chassis. The 16-channel GPS simulator will be available in March 2011.