Abstract: A navigation system for exploring and/or monitoring unknown and/or difficult environments is provided that includes a mission control module, an unmanned vehicle operable for carrying out the exploration and/or monitoring mission, a primary node coupled to the mission control module that includes an ultra-wideband radio interface, and a plurality of secondary nodes for deployment in the unknown and/or difficult environment, each secondary node including an ultra-wideband radio interface. The primary node and secondary nodes are configured to form a hierarchical communication and localization network in which the primary node is associated with a primary hierarchical level and each secondary node is associated with a respective secondary hierarchical level lower than the primary hierarchical level.

Abstract: A method of and a system for synchronizing a plurality of spaced apart nodes of a network to a reference time of a control center, the method comprising receiving measurement data from each of the plurality of nodes; ranking the plurality of nodes with respect to one another according to the measurement data; selecting one or more master nodes from the plurality of nodes according to the ranking; assigning each of the plurality of nodes to a corresponding master node; determining a first time offset between the local time measured at each node and the local time measured at its corresponding master node and determining a second time offset between each of the master nodes and the reference time such that the time offset between the local time measured at each node and the reference time can be determined.

Abstract: A navigation system for exploring and/or monitoring unknown and/or difficult environments is provided that includes a mission control module, an unmanned vehicle operable for carrying out the exploration and/or monitoring mission, a primary node coupled to the mission control module that includes an ultra-wideband radio interface, and a plurality of secondary nodes for deployment in the unknown and/or difficult environment, each secondary node including an ultra-wideband radio interface. The primary node and secondary nodes are configured to form a hierarchical communication and localization network in which the primary node is associated with a primary hierarchical level and each secondary node is associated with a respective secondary hierarchical level lower than the primary hierarchical level.

Abstract: A method of and a system for synchronising a plurality of spaced apart nodes of a network to a reference time of a control centre, the method comprising receiving measurement data from each of the plurality of nodes; ranking the plurality of nodes with respect to one another according to the measurement data; selecting one or more master nodes from the plurality of nodes according to the ranking; assigning each of the plurality of nodes to a corresponding master node; determining a first time offset between the local time measured at each node and the local time measured at its corresponding master node and determining a second time offset between each of the master nodes and the reference time such that the time offset between the local time measured at each node and the reference time can be determined.