Position determining systems and methods are provided. A particular portable device includes a calibration component to communicate with a local positioning system to determine an initial position and orientation of the portable device within a local coordinate system associated with a target structure. The portable device also includes at least one movement sensor to detect movement of the portable device. The portable device further includes a processor to determine a measured position and orientation of the portable device based on the initial position and orientation of the portable device within the local coordinate system and based on the detected movement of the portable device.