  xVIO is a range-visual-inertial odometry algorithm implemented at JPL. It has
been demonstrated with closed-loop controls on-board unmanned rotorcraft
equipped with off-the-shelf embedded computers and sensors. It can operate at
daytime with visible-spectrum cameras, or at night time using thermal infrared
cameras. This report is a complete technical description of xVIO. It includes
an overview of the system architecture, the implementation of the navigation
filter, along with the derivations of the Jacobian matrices which are not
already published in the literature.
