Update rate and latency
The number of position fixes delivered by an RTK system per second also defines how closely the trajectory of the rover can be represented and the ease with which position navigation can be accomplished. The number of RTK position fixes generated per second defines the update rate. Update rate is quoted in Hertz (Hz). The maximum update rate will vary based on the receiver used and the options purchased, and will range between
Solution latency refers to the lag in time between when the satellite measurements were made and when the position was displayed or output. For precise navigation, it is important to have prompt position estimates, not values from two seconds ago. Solution latency is particularly important when guiding a moving vehicle. For example, a vehicle traveling at 25 km/h moves approximately 7 m/s. Thus, to navigate to within 1 m, the solution latency must be less than 1/7 (= 0.14) seconds. The latency is less than 0.020 seconds in Low Latency mode.
With low latency positioning, the rover receiver uses the last received base measurement and extrapolates this correction for a limited time (selectable in the RTK Propagation Limit field between 10, 20, 40, 60 or 120 seconds). The receivers can also be put in Synchronous mode where the rover waits until the base measurements have been received before it computes a position. This mode results in a slightly more accurate position, however the latency is higher due to the delay in receiving the base measurement. See Position screen.
