This avoids creating two pointers of different types to the same memory.
Having two pointers to the same memory can lead to the compiler
optimising code such that a write to one pointer is rearranged to be
either before or after a read from the other pointer depending on
which is deemed faster - not a good outcome.
This change means that provided the GPS_DELAY_MS parameters are set for each GPS receiver attached, the EKF will not have to wait for the configuration of each receiver to be determined before it can start.
This significantly reduces start-up times when the delay parameters are set.
If variance falls below desired minimum, set state noise to a larger value.
If variance drops below safe value, set to desired minimum and reset off-diagonals to zero.
To eliminate the possibility of editing errors, revert the covariance prediction auto-code to the original auto-code without the replacement fo the /2 and /4 operations. The compiler optimisations are able to correctly handle the /2 and /4 operations.
Also use local variables for intermediate covariance calculations. The use of class variables for these small arrays was unnecessary.
This patch ensures that covariance matrix entries for inactive states are always set to zero.
It also halves the number of copy operations from the updated to stored matrix.
Fix rounding error bug preventing state from updating after initial convergence.
Decouple GPS reference height from published EKf origin height.
Add bitmask parameter to control update and publishing of GPS reference height.
If the GPS receiver selection changes and we are using GPS for height, the vertical position will be reset to the new GPS height measurement.
correct output observer history when doing a GPS height reset
Do not time out and provide an escalating series of messages. We may need to adjust the time thresholds used for escalation.
Do not wait if the EKF is not using the GPS.
Use the time delay returned by the GPS driver.
Wait long enough for the GPS configuration to be determined, but time out after 30 seconds and warn the user that a default value for time delay will be used.
Adapt the lengths of the IMU and observations buffers on startup to the specified time delays and update rates.
This does require the EKF to be re-started if time delays are changed.
