Entwicklung Elektronischer Systeme für die Akustische Navigation einer Manövrierbaren Schmelzsonde im Eis : Design of electronic systems for the acoustic navigation of a maneuverable melting probe in ice

• Main Author: Eliseev, Dmitry
• Format: Thesis
• Language: English
• Published: RWTH Aachen University 2018
• Subjects: Phasenarray; phased array; FPGA; Schallausbreitung; Navigation; acoustic; Antarctic; Saturn; Taylor Glacier; The Antarctic; Antarc*
• Online Access: https://dx.doi.org/10.18154/rwth-2018-229383; http://publications.rwth-aachen.de/record/748401

Dissertation, RWTH Aachen University, 2018; Aachen 1 Online-Ressource (VII, 150 Seiten) : Illustrationen, Diagramme (2018). = Dissertation, RWTH Aachen University, 2018 : This thesis describes the development of systems for the acoustic navigation of an in-ice maneuverable probe, which is developed as a part of the Enceladus Explorer (EnEx) initiative of DLR Space Administration. In the context of this initiative, technologies are developed which could facilitate a future space mission to Enceladus, the ice-covered moon of Saturn. At the south polar region of Enceladus the water-rich plumes, venting from the ice, were discovered. It is assumed, that Enceladus hosts an ocean of liquid water below its ice cover, which supplies these plumes. This ocean is one of the most interesting spots to search for the existence of life outside the Earth. Goal of this mission would be to navigate the EnEx probe to a vent, where one of the plumes originates and sample the liquid, supplying the plume. Two systems are considered for the acoustic navigation of the EnEx probe within the ice. The first one is the Acoustic Positioning System (APS) which provides positioning of the EnEx probe. This system operates on the principle of trilateration: calculating position of the probe from propagation delays of the acoustic signals emitted by pingers located near the ice surface. The second system for the acoustic navigation is the Acoustic Reconnaissance System (ARS) which examines the ice region in front of the EnEx probe. The ultrasonography picture is provided by four 16-element phased arrays mounted in the melting head of the EnEx probe. The main focus of this work is the conception and development of electronics for the specified acoustic navigation systems. Some physical and technical aspects are discussed in the context of this development, including: propagation of acoustic waves in inhomogeneous ice, signal filtering, FPGA technology and synchronization issues. As a demonstration of the performance of the probe and its particular systems, numerous tests were carried out: from different tests of individual components up to the in situ tests of the fully integrated probe's setup. The final test of the probe's concept demonstrator took place in cooperation with the MIDGE project at the antarctic Taylor Glacier near the Bloodfalls, where the EnEx probe was able to take samples of liquid from a subglacial conduit. : Published by Aachen