Methods, systems, and apparatus, including computer programs encoded on computer-storage media, for user detection. In some implementations, a corresponding method includes obtaining an authorized user list including first identification information of an Ultra Wide Band (UWB) device; obtaining, from the UWB device, (i) location information of the UWB device at a property, (ii) directionality information of the UWB device, and (iii) second identification information of the UWB device; determining the first identification information of the UWB device matches the second identification information of the UWB device; determining the location information and the directionality information of the UWB device satisfy a predetermined authorization requirement for the property; and sending, to a control device of the property, an access signal that is configured to allow a user associated with the UWB device to access an area of the property.