fix(ekf2): allow optical flow to start when range finder is height reference#26960
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fix(ekf2): allow optical flow to start when range finder is height reference#26960
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…ference When EKF2_HGT_REF=2 (range sensor) with no GPS, optical flow could never start. The starting condition required isTerrainEstimateValid() or isHorizontalAidingActive(), but terrain is never "estimated" when range is the height reference (ground is the datum, terrain state is fixed at 0), and there's no horizontal aiding without GPS. HAGL is directly known from the range measurement in this case, so optical flow has everything it needs to fuse. Add the range height reference check to the optical flow starting conditions. Fixes: #25248
AlexKlimaj
approved these changes
Apr 2, 2026
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Summary
EKF2_HGT_REF=2(range sensor) with no GPS, optical flow can never start because the starting condition requiresisTerrainEstimateValid() || isHorizontalAidingActive()— neither is true since terrain is not "estimated" when range is the height reference (ground is the datum,_state.terrainis fixed at 0), and there's no horizontal aiding without GPS_height_sensor_ref == HeightSensor::RANGEto the starting conditions, consistent with the check already present in the no-horizontal-aiding start path at line 206Fixes #25248
Fixes #26911