Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
i) The positions and orientations of the four OPMs used for reference measurements. The OPMs are positioned such that a measurement of each field component can be made at two different positions to provide a measure of the field gradients. ii) The reference array as set up for an experiment.
