Examples describe systems and methods for iteratively determining a signal strength map for a wireless access point (AP) aligned to position coordinates, positions of a device, and positions of the wireless APs. An example method includes selecting traces and a wireless AP among the traces for which data is indicative of a threshold amount of information to estimate a position of the device and a position of the wireless AP, selecting first characteristics from the traces to remain constant and second characteristics to be variable, and selecting a localization constraint that provides boundaries on the position of the device and the position of the wireless AP. The method also includes performing a simultaneous localization and mapping (SLAM) optimization of the position of the device and the position of the wireless AP based on the localization constraint with the first characteristics held constant and the second characteristics allowed to vary.