Abstract: The simultaneous localization and RF modeling technique pertains to a method of providing simultaneous localization and radio frequency (RF) modeling. In one embodiment, the technique operates in a space with wireless local area network coverage (or other RF transmitters). Users carrying Wi-Fi-enabled devices traverse this space while the mobile devices record the Received Signal Strength (RSS) measurements corresponding to access points (APs) in view at various unknown locations and report these RSS measurements, as well as nay other available location fix to a localization server. A RF modeling algorithm runs on the server and is used to estimate the location of the APs using the recorded RSSI measurements and any other available location information. All of the observations are constrained by the physics of wireless propagation. The technique models these constraints and uses a genetic algorithm to solve them, thereby providing an absolute location of the mobile device.