EnEx-RANGE - Robust autonomous Acoustic Navigation in Glacial icE

Abstract

Abstract. Within the Enceladus Explorer Initiative of the DLR Space Administration navigation technologies for a future space mission are in development. Those technologies are the basis for the search for extraterrestrial life on the Saturn moon Enceladus. An autonomous melting probe, the EnEx probe, aims to extract a liquid sample from a water reservoir below the icy crust. A first EnEx probe was developed and demonstrated in a terrestrial scenario at the Bloodfalls, Taylor Glacier, Antarctica in November 2014. To enable navigation in glacier ice two acoustic systems were integrated into the probe in addition to conventional navigation technologies. The first acoustic system determines the position of the probe during the run based on propagation times of acoustic signals from emitters at reference positions at the glacier surface to receivers in the probe. The second system provides information about the forefield of the probe. It is based on sonographic principles with phased array technology integrated in the probe's melting head. Information about obstacles or sampling regions in the probe's forefield can be acquired. The development of both systems is now continued in the project EnEx-RANGE. The emitters of the localization system are replaced by a network of intelligent acoustic enabled melting probes. These localize each other by means of acoustic signals and create the reference system for the EnEx probe. This presentation includes the discussion of the intelligent acoustic network, the acoustic navigation systems of the EnEx probe and results of terrestrial tests.

Neutrino vertex reconstruction with in-ice radio detectors using surface reflections and implications for the neutrino energy resolution

“…We tested the feasibility to measure the direct and reflected pulse with the following in-situ measurement. We use one ARIANNA detector station installed at Moore's Bay on the Ross Ice shelf that is equipped with a dipole at a depth of −8.6 m. We drilled a 20 m deep hole ∼40 m away from the station using a newly developed portable cylindrical electrothermal drill [27,28] -this technique allowed a fast setup and to drill the borehole for the dipole within a few hours and required very little monitoring.. We installed a dipole antenna at −18.2 m connected through a coax cable to an Avtech pulse generator. The emitting antenna is a copper fat-dipole of 35 cm length and diameter of 5 cm, providing ample clearance in the 9 cm wide borehole.…”

Attenuation of Sound in Glacier Ice from 2 kHz to 35 kHz

“…The instrumentation was deployed in the glacier by holes prepared with a 12 cm diameter melting probe that was developed within the EnEx initiative (Heinen et al, 2017). The layout of the holes at the test site is shown in Fig.…”

An efficient melting probe for glacial research

“…In the EnEx-RANGE configuration, the consists of a melting head, a cylindrical tube holding the control systems and a back plate (Heinen and others, 2016). The diameter is 80 mm and the length has been varied depending on the configuration between 0.6 and 1.2 m with the corresponding weight varying between 6 and 10 kg.…”

“…Within the EnEx-RANGE project (Heinen and others, 2016), a swarm of melting probes (APU – Autonomous Pinger Units) was developed. EnEx stands for Enceladus Explorer, which is an initiative from the DLR Space Administration for the technology development for a future space mission to Saturn's moon Enceladus.…”