Which should I believe? .005 default or .001 max? What is the real recommended range?
Well, the default comes from AP_NavEKF2.cpp
define ABIAS_P_NSE_DEFAULT 5.0E-03f
And the description from lines 374 thru 380
// @Param: ABIAS_P_NSE
// @DisplayName: Accelerometer bias stability (m/s^3)
// @Description: This noise controls the growth of the vertical accelerometer delta velocity bias state error estimate. Increasing it makes accelerometer bias estimation faster and noisier.
// @Range: 0.00001 0.001
// @User: Advanced
// @Units: m/s/s/s
AP_GROUPINFO("ABIAS_P_NSE", 28, NavEKF2, _accelBiasProcessNoise, ABIAS_P_NSE_DEFAULT),
@priseborough or @rmackay9 I don’t know if the default is wrong, or the range description is wrong. @Iketh one of the resident EKF experts will take a look at it.