When Right Now Matters

When systems depend on GNSS not just for position, but for time, trust, and synchronisation, “almost real” isn’t good enough.

Real-time GNSS testing delivers live signals with a current UTC timestamp, allowing engineers to validate time-critical behaviour exactly as it will be experienced in real operation.

If a system expects now, replayed or frozen time can hide problems until it’s too late.

How LabSat enables real-time GNSS testing

Test GNSS-dependent systems using live signals with a current UTC timestamp

Why Use Real-Time GNSS Testing?

Testing with GNSS signals that use a current UTC timestamp exposes problems that are easy to miss when time is replayed, paused, or fixed.

Many modern systems do not simply consume position data. They actively validate GNSS as a trusted source of time. When that time is not current, behaviour in the lab no longer reflects behaviour in the field.

Real-time GNSS testing allows engineers to:

Validate systems that depend on live time, not just valid position
Observe how behaviour changes when time becomes available, drops out, or recovers
Test interactions with external systems that expect continuous, current timestamps

It is used by GNSS and navigation engineers, ADAS and autonomy teams, validation and test engineers, and PNT and timing specialists.

Real-time testing is essential when validating GNSS-dependent systems such as ADAS, V2X, autonomy, aerospace navigation, and connected or IoT devices, where timing accuracy and live system interaction are critical.

Problems Real-Time Testing Solves

Real-time GNSS testing helps engineers identify issues that replay-based testing often hides, including:

Time validity and acceptance

Systems reject GNSS data when time isn’t current.
GNSS loses its role as a trusted time source, leading to unstable behaviour.

Lab vs. real-world mismatch

Software behaves differently in the lab because time is paused, looping or outdated.
Lab tests fail to reflect real‑world operation when connected tools or services expect “now.”

Synchronisation and correlation

Timestamps between GNSS, sensors, logs and external systems fall out of sync.
Test data becomes difficult to align, slowing analysis and masking real issues.

System behaviour over time

Start‑up, recovery and transition states can’t be observed without live time.

These issues often only appear when systems are tested with live GNSS time, making real-time testing a critical step for reliable validation.

See how engineers test this in the lab with real-time GNSS

How LabSat 4 and SatGen Deliver Real-Time GNSS Testing

In this short overview, a LabSat Specialist explains why real-time GNSS testing matters and walks through the four simple steps used to conduct testing with LabSat 4 and SatGen.

Real-time GNSS testing shouldn’t be complicated.

LabSat 4 and SatGen provide a real-time GNSS test solution that fits naturally into day-to-day development and validation work, without forcing changes to existing workflows or test setups.

1. Create your GNSS test route

Build the trajectory you want to test, based on real or simulated movement that reflects your intended scenario.

2. Define your GNSS conditions

Set the conditions that matter to your system, such as individual satellites and their attenuation level.

3. Select your GNSS signals

Choose the constellations and bands your receiver or application actually uses.

4. Simulate GNSS in real-time

Generate live GNSS signals with a current UTC timestamp, allowing your system to operate exactly as it would in deployment.

Talk to our experts about real-time GNSS testing

LabSat Benefits for Real-Time Testing

Alongside real-time capability, LabSat 4 and SatGen deliver the core benefits engineers expect from all LabSat solutions:

Cost-effective

Cost-effective access to real-time GNSS testing in the lab

Intuitive

Straightforward, intuitive setup for rapid testing

Seamless

Easy integration with existing test systems and workflows

Flexible

Clear hardware options with a defined upgrade path

Transparent

No hidden licensing or usage costs

Reliable

Ongoing software updates and lifetime technical support included

Talk to our experts about real-time GNSS testing.

Frequently asked questions

We've attempted to answer some of the more commonly asked questions regarding the end-of-line testing with LabSat. However, if there's anything we've not been able to answer please don't hesitate to get in touch and one of our LabSat engineers will be delighted to help you.

Do I need real-time GNSS testing if replay already works for my system?

If your system accepts GNSS data without validating time, replay may be sufficient.

If your system expects current UTC, relies on time as a trust anchor, or interacts with external systems that validate “now”, real-time testing is essential to avoid false confidence.

What’s the difference between replaying a standard SatGen scenario and real-time GNSS testing?

Standard replay testing generates pre-defined GNSS signals with a fixed UTC timeline defined by the user during scenario generation, enabling highly repeatable validation of positioning, navigation, and receiver behaviour under controlled conditions.

Real-time testing generates live GNSS signals with a current UTC timestamp, enabling validation of time-dependent behaviour and system interactions.

Which applications benefit most from real-time GNSS testing?

Real-time testing is commonly used for ADAS, autonomy, V2X, aerospace, PNT, timing-sensitive receivers, connected systems, or any application where GNSS time affects system behaviour or trust.

Can LabSat 4 and SatGen real-time testing be integrated into existing test setups?

Yes. LabSat 4 and SatGen are designed to integrate easily with existing lab environments, tools, and validation workflows.

Is real-time GNSS testing complex to configure?

No. Real-time testing with LabSat 4 and SatGen follows the same structured workflow as other LabSat testing, using clear steps and familiar configuration tools.

Talk to us about your real-time GNSS testing requirements