Clarifies use of EK2_RANGE_USE_HGT and EK2_ALT_SOURCE parameters to control range finder use.
Setting EK2_RNG_USE_HGT to a positive number to enable automatic switching between the primary height source (baro or GPS) and range finder should be disabled if any primary height source other than Baro or GPS is selected via the EK2_ALT_SOURCE parameter.
../../libraries/AP_NavEKF2/AP_NavEKF2_core.cpp: In member function ‘void NavEKF2_core::InitialiseVariables()’:
../../libraries/AP_NavEKF2/AP_NavEKF2_core.cpp:343:50: warning: ‘void* memset(void*, int, size_t)’ clearing an object of non-trivial type ‘struct NavEKF2_core::ext_nav_vel_elements’; use assignment or value-initialization instead [-Wclass-memaccess]
343 | memset(&extNavVelNew, 0, sizeof(extNavVelNew));
| ^
In file included from ../../libraries/AP_NavEKF2/AP_NavEKF2_core.cpp:4:
../../libraries/AP_NavEKF2/AP_NavEKF2_core.h:518:12: note: ‘struct NavEKF2_core::ext_nav_vel_elements’ declared here
518 | struct ext_nav_vel_elements {
| ^~~~~~~~~~~~~~~~~~~~
../../libraries/AP_NavEKF2/AP_NavEKF2_core.cpp:344:58: warning: ‘void* memset(void*, int, size_t)’ clearing an object of non-trivial type ‘struct NavEKF2_core::ext_nav_vel_elements’; use assignment or value-initialization instead [-Wclass-memaccess]
344 | memset(&extNavVelDelayed, 0, sizeof(extNavVelDelayed));
| ^
In file included from ../../libraries/AP_NavEKF2/AP_NavEKF2_core.cpp:4:
../../libraries/AP_NavEKF2/AP_NavEKF2_core.h:518:12: note: ‘struct NavEKF2_core::ext_nav_vel_elements’ declared here
518 | struct ext_nav_vel_elements {
| ^~~~~~~~~~~~~~~~~~~~
This limits the use of the reset to situations where it is a last ditch resort before a lane switch and failsafe.
This will limit false positives for general deployment, but still provide protection from fly-aways at the cost of some increase in reaction time.
Separate prediction and correction steps are required to provide an up to date yaw estimate using IMU prediction before it may be required by SelectMagFusion() whilst still doing the velocity update after GPS data haw been pulled from the buffer by SelectVelPosFusion()
