A method of determining a new Position for a Node n, said Node n having a distance measuring radio, said method comprising the steps of: a) Obtaining a list of Positions of a plurality of neighboring Nodes, b) Analyzing the geometric relationship of the Positions in said list and the predicted Position (pP) of Node n, c) Selecting subset of the Nodes from said list that is less than the total number of Nodes in said list, d) Performing electronic distance measurements from Node n to each of said subset of Nodes, e) Utilizing distances obtained in step d) to determine a new Position of Node n, wherein step a) further comprises obtaining corresponding Confidence metrics for each said Position in said list, and the selection in step c) is based at least in part on said Confidence metrics, characterised in that the method further comprises the step of computing, taking inertial inputs from an Inertial Navigation System, INS, whether a Node is in motion and computing the direction of travel, the result of motion computation being used to adjust Confidence of the node's Position and to switch node roles between Anchor, Breadcrumb, and Tag, Node roles being used as criteria for selecting most favorable sets of distance measurements, with the highest preference being given to Anchors, then Breadcrumbs, then Tags, a Breadcrumb being a Tag that has been stationary for an extended period of time, the primary difference between an Anchor and a Breadcrumb being that an Anchor's position is explicitly known and assigned when the Anchor is placed whereas a Breadcrumb's position was calculated when it was moving as a Tag, but has higher Confidence than that of a moving Tag due to having been stationary and having the benefit of a number of repetitive measurements being considered over time to reduce error. a) Obtaining a list of Positions of a plurality of neighboring Nodes, b) Analyzing the geometric relationship of the Positions in said list and the predicted Position (pP) of Node n, c) Selecting subset of the Nodes from said list that is less than the total number of Nodes in said list, d) Performing electronic distance measurements from Node n to each of said subset of Nodes, e) Utilizing distances obtained in step d) to determine a new Position of Node n, wherein step a) further comprises obtaining corresponding Confidence metrics for each said Position in said list, and the selection in step c) is based at least in part on said Confidence metrics, characterised in that the method further comprises the step of computing, taking inertial inputs from an Inertial Navigation System, INS, whether a Node is in motion and computing the direction of travel, the result of motion computation being used to adjust Confidence of the node's Position and to switch node roles between Anchor, Breadcrumb, and Tag, Node roles being used as criteria for selecting most favorable sets of distance measurements, with the highest preference being given to Anchors, then Breadcrumbs, then Tags, a Breadcrumb being a Tag that has been stationary for an extended period of time, the primary difference between an Anchor and a Breadcrumb being that an Anchor's position is explicitly known and assigned when the Anchor is placed whereas a Breadcrumb's position was calculated when it was moving as a Tag, but has higher Confidence than that of a moving Tag due to having been stationary and having the benefit of a number of repetitive measurements being considered over time to reduce error. <EOS>