In some embodiments, apparatus and systems, as well as methods, may operate to obtain hole azimuth data or inclination data associated with a chassis (e.g., comprising a measurement or logging tool) in a borehole using interpolated data or survey data, and to determine magnetic field orientation of the chassis using a portion of the hole azimuth data, a portion of the inclination data, relative bearing data, and Earth magnetic field orientation data by reconstructing at least a portion of borehole magnetic field data that is corrupt or missing. Additional apparatus, systems, and methods are disclosed.