The latency on the speed output is particularly important as it can become the dominant source of error in many test applications. If a vehicle is decelerating at 1g (typical for a brake test), every 1ms of latency gives approximately 0.01m/s error in speed output. Given that the accuracy of the GPS speed measurement is in the same order of magnitude, it is essential that the latency is only a few milliseconds to avoid this dominating the total speed error during a dynamic test. Early GPS systems were particularly bad in this respect and with poor GPS reception the speed outputs were heavily filtered to hide the noise, which often resulted in latencies in excess of 500ms.
The SPEEDBOX20 internal calculations and output routines have been carefully designed and optimized to have latency of just a few milliseconds as shown in below:
SPEEDBOX20 output latency