Applies to v0.1.0.

GNSS

The position sensor: where the car is.

Add it

Sensor Setup → Sensor Type GNSS → GNSS Sensor → place it where the antenna sits on your real car.

There is nothing to tune, on purpose

The panel says it plainly:

Reports the antenna's world position, in metres.
Ground truth — there is no receiver on the real car.
Mount it with Extrinsics below.

No satellites are simulated and no noise is added: the reading is the exact position of the antenna, every time. That makes it the reference the other sensors are judged against.

The one setting that matters

Extrinsics. The reading is the antenna's position, so where you mount it is the measurement. Put it at the same spot as on the real car, or the two positions will disagree by exactly the mounting difference.