Keywords: 4D-RCS reference model architecture typical high level block diagram.jpg en A high level block diagram of a typical 4D/RCS reference model architecture Commands flow down the hierarchy and status feedback and sensory information flows up Large amounts of communication may occur between nodes at the same level particularly within the same subtree of the command tree UAV Unmanned Air Vehicle UARV Unmanned Armed Reconnissance Vehicle UGS Unattended Ground Sensors 4D-RCS A Reference Model Architecture For Unmanned Vehicle Systems Version 2 0 Albus et al National Institute of Standards and Technology Gaithersburg Maryland 20899 2002-08 PD-USGov 4D-RCS Reference Model Architecture RCS Reference Model Architecture Reference models |