A method for collaborative navigation comprises initializing a conditionally independent filter on a local platform, propagating the conditionally independent filter forward in time, and when a local measurement has been made, updating the conditionally independent filter with the local measurement. When a common measurement has been made, the conditionally independent filter is updated with the common measurement, and a determination is made whether a remote conditioning node has arrived from a remote platform. If a remote conditioning node has arrived, a determination is made whether the remote conditioning node needs to be fused with a local conditioning node of the conditionally independent filter. If the remote conditioning node needs to be fused, a node-to-node fusion is performed in the conditionally independent filter to merge the remote conditioning node with the local conditioning node to produce a merged conditioning node. A conditional update of the conditionally independent filter is then performed.