The current amplitudes are set to produce a series of {HEAD ~ spatial current patterns}, all orthogonal to each other, and {TAIL ~ each} applied for only a short time interval while voltages are measured 
The current amplitudes are set to produce a series of { HEAD ~ spatial current patterns } , all orthogonal to each other , and { TAIL ~ each } applied for only a short time interval while voltages are measured
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH