In some embodiments, an apparatus and a system, as well as a method and an article, may operate to determine spatial orientations of one or more transmitters attached to a first downhole component, relative to one or more receivers attached to a second downhole component, at common points in time during rotation of the first and the second downhole components. The first downhole component may be variably, rotationally coupled to the second downhole component. Further activity may include transforming raw measurements of transmitter signals provided by the receiver(s) into calibrated measurements based on the spatial orientations at the common points in time. Additional apparatus, systems, and methods are described.