Tethered Lifting Systems as a Flexible Boundary Layer Platform for Ship-Based Measurements

~71% of the Earth is covered by water, of that water 100% is covered by the Atmospheric Boundary Layer (ABL).

The Air-Sea interaction is of increasing scientific interest and the focus on simultaneous marine environment measurements to cover both sides of the interface presents a challenge for Boundary Layer researchers not found in land-based campaigns.

Tethered balloon systems (Helikites, etc.) can be an innovative ABL instrumented aerial measurement platform and their use for shipboard deployment, constitutes a very novel adaptation. They provide great enhancement to ship-based Boundary Layer measurements for very little cost compared to other sensors such as lidar, UAS, satellite, etc. Kites add lift and stability but are harder to recover due to the extra lift. These flexible systems allow for top mount upward line-of-sight (LOS) or downward/slant path viewing that can be made reasonably rigid or stable. This includes mountings on the balloon itself, along the tether line attached directly, or to specific points using leaders or harness assemblies.

Balloons act as readily scalable platforms, with balloon size changes requiring very little logistical infrastructure. Balloons in storage take very little space while balloon sizing options give payload (lift) vs. operational requirement tradeoffs. Typically, the more lift capability, the more challenging to deploy, recover and store. However, this allows the operation of tailored package(s) as needed, size vs lift vs launch/recovery conditions primarily. The winch remains the linchpin of the operation, it needs to be capable for the load and precisely controllable. This is what allows for varying flight strategies to be matched against instrument best use practices. Flight duration can be on the order of minutes to weeks, depending on configuration and need. Given that ship location, heading, and positioning are selectable mission parameters; ship-based flight operations are, in some ways, more consistent than their land-based counterparts.

Lessons learned can be used in land-based scenarios that might not be considered viable otherwise. The tethered balloon system gives another tool in the Boundary Layer researcher’s tool box to improve experiment data sets, filling a niche between in-situ sensors and remote sensing devices.