GNSS simulators are used in labs around the world to develop and test robust positioning, navigation and timing systems. Unlike live sky testing, simulators provide full control of the satellite signals and environmental conditions of the test. Simulations can include scenarios for any location, from Earth to the Moon, and at any time past, present or future.

For some applications, the ability to synchronize the simulation time and/or orbital parameters with the live sky GNSS time and ephemeris is critical.
Spirent Standpoint addresses this need, enabling simple and precise synchronization in the lab or in the field.

Brochures

Key benefits

Realism

• 50 ns synchronization between simulator time and live sky GNSS time
• Alignment of orbital parameters in real-time in simulated scenario
• Enables spoofing testing using live sky GNSS signals

Cost

• Standpoint enables powerful spoofing testing with a single RF output GNSS simulator

Time

• Removing the need to cold start a receiver when moving from the real world to the lab can save a significant amount of engineering time
• Remove the need to invest time and money designing, testing and implementing your own live sky synchronization

Introducing Standpoint

Standpoint comprises two key components: the Standpoint Reference Receiver and the Standpoint Software Utility.

Standpoint Reference Receiver

The reference receiver acquires the live sky GNSS signals from an active antenna (provided), synchronizes the Spirent GNSS simulator via 1PPS and 10 MHz signals, and passes live sky satellite data to the simulator via a USB connection.

Standpoint Software Utility

The Standpoint Software Utility is a web service application used to control the reference receiver and communicate with the simulator control software – PosApp. The utility is installed on the simulator’s controller, or on a separate controller, if required.

Use cases

Lab-based live sky synchronization

The first task when connecting any device under test (DUT) to a GNSS simulator is to cold start the GNSS receiver. This clears position, time, almanac and ephemeris from the module’s memory. However, in some cases, cold starting the receiver is not possible:

• When the receiver is embedded in a product with no access to cold start
• When the DUT uses another live time source that must match the receiver time (e.g. in-vehicle infotainment getting time from GNSS and cellular)
• When long time to first fix (TTFF) impacts time constraints

Standpoint overcomes the need to cold start the GNSS receiver by aligning the time, almanac and ephemeris of the GNSS simulator with real world signals.

Spoofing testing

Spoofing testing can be conducted by coupling two synthetic signals generated by a GNSS simulator. With direct control over both the “real” and spoofed signals, it is relatively simple to align pseudoranges. However, this method is very much a worst-case scenario. Using live sky signals represents a better test case - spoofing a device that is positioning using real signals more accurately represents real-world operational threats.
However, the first epoch of simulation must be tightly aligned to the real signals, and this makes the test set-up more complicated. Standpoint is capable of synchronizing to live sky with an accuracy of 50 ns. This enables realistic spoofing testing, with live sky signals providing the truth data, and complete user control over the spoofed signals. Standpoint integrates seamlessly with Spirent GSS7000 and GSS9000 GNSS simulators, making set-up of spoofing tests easier and faster than ever before