According to an example, a signal space based navigation apparatus may receive traces of wireless signal observations and corresponding pedestrian deadreckoning (PDR) traces between different ones of the wireless signal observations from a plurality of user devices. A plurality of wireless clusters may be generated based on the traces of wireless signal observations. A PDR displacement vector may be generated between two or more of the wireless clusters based on the two or more of the wireless clusters and a subset of the PDR traces corresponding to the two or more of the wireless clusters. A sensing map may be generated based on the plurality of wireless clusters and a plurality of PDR displacement vectors including the PDR displacement vector.