Development and coordination of practical balloon swarms for persistent, in situ, realtime measurement of hurricane development
This project proposes a lowcost balloon observation system for sustained (in time), broadly distributed (in space), insitu (between 18km altitude), realtime measurement (from data acquisition to NCAR within 20 minutes) of hurricane development. The high density (in both space and time) measurements from such a robotic vehicle swarm will be invaluable in significantly improving our ability to estimate and forecast such extreme and dangerous atmospheric events.
Challenges in this overarching problem, which is of acute societal relevance, include:

the design of small (3 kg, 5.5 m3 at 8 km altitude), inexpensive (< $ 2k), robust, sensorladen, buoyancycontrolled balloons that don’t accumulate ice, and are deployable from the launch chutes (13 cm diameter x 91 cm long) of existing NOAA P3 aircraft [mbdb17],

the implementation of a selfreconfiguring Mobile Ad hoc Network (MANET) over the (mobile) balloon swarm, leveraging ultralowpower cellphone (LTEDirect) or IoT (Sub1 GHz) radios communicating in the UHF band over (typically) 10 to 30 km distances, and

the development of efficient hierarchical systemslevel control algorithms to autonomously coordinate the vertical motion of the balloons in the swarm to move them with the hurricane, simultaneously achieving both good coverage and good connectivity while minimizing the control energy used, leveraging the strong vertical stratification of the horizontal winds. We have so far developed two algorithms for this problem, which we now work to combine:

a (centralized) Model Predictive Control (MPC) strategy for coordinating the largescale balloon distribution, leveraging the coarse flow forecasts developed with the cuttingedge hurricane Weather and Research Forecasting (WRF) code developed at NOAA [BM16], and

a (decentralized) ThreeLevel Control (TLC) strategy for rejecting the smallerscale disturbances that arise due to unresolved flowfield fluctuations, which induce a statistical “random walk” in the balloon trajectory away from that planned by the MPC formulation [mlb16], [MLB17].