Accuracy & Testing

Centimetre-level positioning. Sub-millisecond timing.

A dual-band RTK GPS device on the car and a base station at the venue time each crossing of a virtual line to within 1 ms. There are no cables to run and no pavement to cut. The same device is also a data logger for the driver.

A blue pickup truck cornering on a track at golden hour, with three timing units on its roof.
Test rig: three independent units on one vehicle. Prototype units during accuracy testing.
Verified Repeatability
±1 ms

Consistent spread across independent devices on the same vehicle.

QA Pass Standard
100 consecutive hits per unit

Calibrated multi-marker passes against other systems before delivery.

Auditable Accuracy
Every hit

Every crossing is stored with telemetry to audit the accuracy of that individual record.

Optical Benchmark
15.6 ms avg

In our testing, discrepancy range (1.3 to 56.3 ms) observed on commercial optical lasers while Sidereal matched within 1 ms.

Three timing units on a car dash, seen from the driver's seat, each showing a lap time.
Lap time on three units on one car, left to right: 81.234, 81.235 and 81.234. Prototype units during accuracy testing.
Three timing units on a car dash, seen from the driver's seat, each showing a lap time.
A different run, left to right: 78.233, 78.234 and 78.233. The middle display is caught mid-refresh. Prototype units during accuracy testing.
The physics

Why personal loggers and phone apps can't give millisecond timing.

Personal loggers and phone apps (1–25 Hz)

±1 to 2 metre drift

Phone apps use the phone's built-in GPS, which updates once a second and has limited accuracy. Personal data loggers update 10 to 25 times a second, but without RTK corrections their position still drifts by a metre or two. Most GPS loggers are about 100 times less accurate than Sidereal (about 1 m against 1 cm). At 100 km/h a car covers one metre every 36 ms, so a two-metre drift is 72 ms of timing uncertainty, enough to change podium positions in a tight championship.

Dual-band RTK GPS

±1 centimetre precision

A stationary base station calculates atmospheric and orbital errors in real time and broadcasts corrections across the venue. Each device then works out the moment it crosses the virtual line, with sub-millisecond precision, and records the whole run as data for the driver.

Verification & testing

How we tested our timing accuracy.

How a crossing is timed, how it compares with optical lasers, what the audit record holds and where to mount the device.

Want to compare it against your current system?

We welcome running Sidereal side-by-side with your existing photocell beam or transponder setup at an event so you can see the comparison on your own timing sheets.