In an example implementation, {TAIL ~ tall structures} in the array are light emitting and act as {HEAD ~ a light emitting visual display} which further comprises an array of vignetted light sensors 
In an example implementation , { TAIL ~ tall structures } in the array are light emitting and act as { HEAD ~ a light emitting visual display } which further comprises an array of vignetted light sensors
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH