VIO — Visual-Inertial Odometry

Visual-inertial odometry (VIO) sensors give a drone its position, velocity and attitude without GPS by fusing a camera, an IMU and a rangefinder on the module itself. Unlike an optical flow sensor, which only reports a velocity, a VIO sensor outputs a full pose over MAVLink, so ArduPilot and PX4 aircraft can hover, hold position, fly waypoints and return to launch indoors, under bridges, in tunnels and anywhere satellites fail. Read VIO vs Optical Flow to see which sensor your build needs.