As the GPS is an independent* system, its speed calculations are not subject to the same sources of error as the vehicle's speedometer.

Its speed calculations are not subject to the same sources of error as the vehicle's speedometer (wheel size, transmission/drive ratios).

This allows the train's signalling computers to account for this in speed calculations.

Block Length, which can vary quite a bit, and is also important in speed calculations.

VASCAR is a device that semi-automates the timing and average speed calculation of the original manually operated "speed trap".

With the wheel size in mind, the bike computer can translate the number of rotations into a speed calculation.

This, as well as deceleration to zero speed, is illustrated with the green line in the "Permitted and supervised speed calculation" figure.

I'll cut to the chase: Nike+ on the new iPod nano was not particularly accurate for me on speed or distance, but the poor speed calculation is likely because of the inaccurate distance estimate.

With that data, it generates highly accurate route maps, speed calculations, changes in elevation and other information.

The prosecutor accused Julienne of "not taking all the necessary measures for the security of the stunt in question" and notably to have "neglected the speed calculations of the car and the length of the jump".