Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for resolving erroneous movement signals and for providing navigation instructions. One of the methods includes receiving data from two or more sensors, synchronizing the received data, determining a first subset of the synchronized data from the camera for a particular period of time and a second subset of the synchronized data from the other sensor for the particular period of time, comparing the first subset with the second subset to determine whether the first subset and the second subset indicate an erroneous movement signal, based on determining that the first subset and the second subset indicate an erroneous movement signal, selecting data for one of the sensors based on a sensor priority scheme for the sensors, and resolving the erroneous movement signal based on the selected data for the one of the sensors.