I am a systems engineer working with various instrumentation devices for ground platforms. These platforms can vary in speed from 0-60+mph. Current instrumentation provides TSPI at 1Hz and is based on GPS. We are looking at a new system that claims to provide TSPI up to 20Hz. I have no additional details at this time on what additional sensors are in the loop.
Since GPS uses 1PPS, how do you get 20Hz TSPI? IMUs?
Best Answer
All modern GPS receivers will provide you with a position update rate of 5Hz or 10Hz (e.g.MTK3339). However, the speed signal the GPS provides is derived from the satellite signals and not from the position update rate. The speed can alternatively be calculated from one position to the next one (difference of position divided by passed time). If that method is used a higher position update rate is desired because a sudden change of speed will need too long to be visible.
As someone else mentioned the 1PPS has nothing to do with that, it is only a clock reference independent from speed or update rate.