How to use GPS record, replay and simulation to test your navigation systems more effectively

Different road designs, numerous types of intersections, and driving on the left or right-hand side are the tip of the iceberg when it comes to challenges faced by navigation system developers.

In addition, the cost of field testing in many countries and on different continents is large. So how do you accurately and consistently test your firmware or software? For many leading navigation suppliers and developers, the answer lies in record, replay, or simulation of GPS and Multi-GNSS signals.

Using Racelogic’s LabSat GNSS record, replayer and simulator, you can create real live traffic situations and journeys. Multiple scenarios can then be replayed many times in your testing facility.

Not only will you test against real signal conditions but you will be able to see how your software performs if drivers go off route and miss turns. The ability for your software to recover from the unexpected is essential in today’s competitive navigation marketplace, because this is when your customers will need your product the most.

How do you know what the recording conditions were like during the test?

During a ‘Live Sky’ GNSS signal recording, LabSat records the exact time as part of the file. By using a Racelogic Video VBOX data logger at the same time to record a live video file, the exact time coding is recorded into the video.

LabSat can then replay the recorded GNSS scenario and send the time synchronisation to the PC playing the video. This means the footage is perfectly synced together with the GNSS RF signals, which allows you to see the video replaying the journey at exactly the same time as your navigation software is travelling along the route. Any failures can be observed repeatedly, and after a solution is created you can test against the exact conditions recreated during the replay.

By recording scenarios in difficult signal reception conditions such as tunnels and underpasses, and by going on and off the scheduled route, the real life complexity of modern driving conditions can easily be captured in a way that is not possible with simulators.

These recorded scenarios can then be used time and time again to standardise your testing regime so that different versions of software and firmware can be verified to ensure consistent performance. You can even test different versions of your mapping database.

LabSat also enables you to record information from an Inertial Measurement Unit (IMU) together with CAN vehicle data into the recorded file, to be replayed exactly as it happened. This versatility and consistent replay quality has given LabSat the market leading position in the global GNSS record and replay market.

Do you need a LabSat Record and Replay Model?

To make your testing even more cost effective you can mix and match LabSat models to suit your individual needs. We offer three variants within the LabSat (GPS & Galileo) and LabSat 2 (GPS, Galileo, GLONASS & BeiDou) model ranges: Record & Replay, Record Only and Replay Only.

Many clients find it very useful to have multiple Replay Only devices for engineers and developers to run continuously in their test or production facility and to have separate device to do the recording, which can also record data from GNSS simulators. Racelogic also offer a customer defined scenario facility whereby we will create a custom scenario for you.

Please contact us for further information >

Can you test your device or application remotely, anywhere in the world?

It is good product development practice to test your device or application for well known problems. For example many developers have found problems with GPS applications that cannot process negative latitude or longitude coordinates or the decimal degrees experienced when close to or crossing the meridian line.

Racelogic’s SatGen software creates scenarios anywhere in the world in a number of static or dynamic situations. This versatile software can create user defined dynamic paths from NMEA, Google KML or VBOX files. This allows for scenario creation anywhere at any time. It is capable of replicating anything from a motorway, rural or suburban roads, to a complex city centre intersection with multiple lane changes and traffic lights.

LabSat can also record from a GPS simulator and replay this in the lab, which is useful for testing signals that do not yet exist, such as the full Gallileo constellation.

Can I test multiple constellations?

There are currently three operational GNSS constellations: GPS, GLONASS and BeiDou. These are all covered by LabSat 2, as is the Gallileo constellation under development.

LabSat is also capable of recording the signals from the augmentation systems. The Space Based Augmentation Systems (SBAS) provide satellite broadcast correction signals back to earth to improve accuracy and integrity.

LabSat will record both the US based Wide Area Augmentation System (WAAS) and the European Geostationary Navigation Overlay Service (EGNOS) signals alongside the GPS, GLONASS and BeiDou navigation signals. Therefore, during replay you can test your device’s ability to use these services without leaving the Laboratory.