  This paper presents the portable autonomous probing system (APS), a low-cost
robotic design for collecting water quality measurements at targeted depths
from an autonomous surface vehicle (ASV). This system fills an important but
often overlooked niche in marine sampling by enabling mobile sensor
observations throughout the near-surface water column without the need for
advanced underwater equipment. We present a probe delivery mechanism built with
commercially available components and describe the corresponding open-source
simulator and winch controller. Finally, we demonstrate the system in a field
deployment and discuss design trade-offs and areas for future improvement.
Project details are available on
https://johannah.github.io/publication/sample-at-depth our website
