This is also from the older version of the generator.
Note that as documented, some of the equations have been removed and
rearranged slightly as it is assumed their terms are zero. Additionally,
the result is taken as the sum of the diagonal entries of the matrix.
Validated that the generated code matches exactly the code in AP_NavEKF3
(except for the early exits).
Delete `covariance_generated.cpp` as we know exactly how to generate it
now (and it was out of date anyway).
this is only used in one place, and that place is called from the same routine setting the persistent state. The only other place which calls readIMUData shouldn't be running the prediction step, but mmay, depending on the previous setting of the prediction step.
We are not initialising this state on filter reset, so it's possible that the state will be set when we do an InitialiseFilterBootstrap, which is probably not desired
The previous method resulted in data incest and fusion of predicted airspeed on every EKF internal time step.
This was not apparent during flight where the vehicle was turning, but during long straight legs did not constrain along track drift.
These changes enable the EKF to use the last observable wind velocity vector estimate to synthesise an airspeed measurement if operating without an airspeed sensor and when all other measurement types that can constrain velocoty drift are lost. This enables the EKF to use dead reckoning to continue after loss of GPS when there is no air speed sensor fitted and without the need to set a default airspeed value.
The logic used to fuse a default airspeed value has also been cleaned up and the call to FuseAirSpeed() from inside SelectBetaDragFusion() has been removed.
AP_NavEKF3: Fix error in default airspeed observation variance
AP_NavEKF3: Enable shadow fusion of airspeed when sensor is disabled
we don't need to persist this across multiple calls as we now fuse all axes on the one step.
I've moved the defintion of these variables to where they are initialised to make it clear they're not used uninitialised.
When returning our last-known-position we were supplying lat/lng but not
altitude.
This usually really doesn't matter as this result generally isn't used,
especially for altitude. OTOH, it may prevent a bug into the future.
Fixes bug that prevents the vertical velocity being reset to the GPS if the position aiding has already timed out and improves sensitivity of the bad IMU data check.
this processes GPS yaw with its own timestamp and as a separated step
from fusing position and velocity. This makes the yaw time handling
more accurate as yaw for moving baseline GPS comes in as a separate
piece of data from the position and velocity
