Non-GPS EKF Initialization in Ardupilot

Properly the EKF is important for two reasons: 1. Significantly better dead reckoning performance than DCM mode 2. Cyclops consumes LOCAL_POSITION_NED (32) which is ≈ only published if the EKF has booted in flight. Ardupilot's EKF has unintuitive requirements for initialization. If you do not provide a GPS at startup, or an ExtNav input like a VIO or Optical Flow, Ardupilot will not properly boot the EKF. For more technical users, this forum post provides a great overview. Advanced users who are used to flying without a GPS will likely already have a method to bootstrap their EKF. If you are familiar with this problem and have solved it for your platform, we recommend that you continue using your preferred method. We have tested and provide an Optical flow solution for VTOL fixed wings that works with stock Ardupilot, and a patch for Ardupilot that will enable you to initialize the EKF using only an airspeed sensor.

Optical FlowArdupilot Patch