If anyone is curious, as I was, about the large red shapes on the map, those are the beams of the object tracking/measurement sites. They correlate with the maps at [0]. I was actually pretty blown away when I started reading that page. Apparently those stations can measure <10cm-sized debrisin orbit. What?! Amazing.
The instrument is the particular radar. They usually have two at each location. Each radar is essentially a linear phased array that creates multiple possible beam locations in the radar plane. They light up a beam as a satellite passes through in order to collect measurements. TLDR an instrument has multiple beams.
[0] https://leolabs.space/radars/