  In this paper, we discuss the design of a sliding-correlator channel sounder
for 28 GHz propagation modeling on the NSF POWDER testbed in Salt Lake City,
UT. Beam-alignment is mechanically achieved via a fully autonomous robotic
antenna tracking platform, designed using commercial off-the-shelf components.
Equipped with an Apache Zookeeper/Kafka managed fault-tolerant
publish-subscribe framework, we demonstrate tracking response times of 27.8 ms,
in addition to superior scalability over state-of-the-art mechanical
beam-steering systems. Enhanced with real-time kinematic correction streams,
our geo-positioning subsystem achieves a 3D accuracy of 17 cm, while our
principal axes positioning subsystem achieves an average accuracy of 1.1
degrees across yaw and pitch movements. Finally, by facilitating remote
orchestration (via managed containers), uninhibited rotation (via
encapsulation), and real-time positioning visualization (via Dash/MapBox), we
exhibit a proven prototype well-suited for V2X measurements.
