Date of Award

Fall 11-2019

Access Type

Thesis - Open Access

Degree Name

Master of Science in Electrical & Computer Engineering

Department

Electrical, Computer, Software, and Systems Engineering

Committee Chair

Aroh Barjatya

First Committee Member

Eduardo Rojas

Second Committee Member

Tianyu Yang

Abstract

AFOSR Multidisciplinary University Research Initiative (MURI), "Integrated Measurement and Modeling Characterization of Stratospheric Turbulence", is a 5-year effort to resolve significant operational issues concerning hypersonic vehicle aerothermodynamics, boundary layer stability, and aero-optical propagation. In situ turbulence measurements along with modeling will quantify spatiotemporal statistics and the dependence of stratospheric turbulence on underlying meteorology to a degree not previously possible. Data from high altitude balloons sampling up to kHz is required to characterize turbulence to the inner-scale, or smaller, over paltitudes from 20 km to 35+ km.

This thesis presents the development of a standard balloon bus, based on reliable COTS components, that includes radios operating in Ham/ISM frequencies with high-gain ground station antennas to achieve high telemetry rates that potentially enable sub-cm scale sampling. It also presents the development of controlled descent systems based on reliable COTS components that allow high resolution unperturbed measurements during the descent of the balloon payloads. Both single and double balloon configurations for a controlled descent are investigated while maintaining a suitable cost for mass production of the system. We are also investigating configurations for multiple ground station to allow the use of Single Payload Multiple Ground Stations strategies to facilitate low error rate high volume data downlinking and closely-timed launches. The performance of using some retransmission techniques to download the data over altitudes from 20 to 35+km when the balloon is out of the altitude range of interest (below 20 km) is analyzed; thus, being able to reduce the percentage of packet losses even during slow descent rates, reaching long slant ranges.

This thesis is designed and implemented using Arduino IDE and MATLAB for software development and testing, circuit design with National Instrument's Multisim and Ultiboard, transceivers configuration with proprietary software, extensive components and system testing, 3D printing, temperature calibrations using a TestEquity temperature chamber, and actual high-altitude balloon launches for final performance analysis.

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