Wireless subglacial instrumentation

Lead Research Organisation: University College London
Department Name: Electronic and Electrical Engineering


The subglacial environment hosts populations of microorganisms, controls ice sheet motion, and ultimately helps determine the fate of ice on planet Earth. It is an environment however that is very challenging to observe.

Through a preliminary field trial in Greenland, researchers from Cardiff University and UCL have recently shown that a unique ice penetrating radar and novel electronic tracer sensors can be combined as a system to recover geophysical parameters from boreholes to depths of 60 m through temperate ice over a prolonged period. The challenge now is to optimise the design of these previous independently-engineered systems and realise a prototype that can be used to wirelessly recover geophysical data from the subglacial environment through greater than 2 km of glacial ice and, moreover, be able to track the spatial location(s) of the sensor(s) providing that data.

This PhD project will investigate the algorithms and system architectures required to achieve sensor localisation and geophysical data retrieval from the subglacial environment. We aspire for the project to culminate in prototype sensors and radar that will be tested in the polar regions - this will be the first study of its kind in the UK.

Relevance to EPSRC thematic areas: Engineering (sub-theme: RF & Microwave Communications), Physical sciences (sub-theme: sensors and


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Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/N509577/1 01/10/2016 24/03/2022
1824233 Studentship EP/N509577/1 01/12/2016 31/03/2021 Abdul Karim
Description The continued disintegration and melting of the ice shelves in the Antarctic Peninsula and
the polar world a great concern to the scientific community. Understanding the basal melt
rates in polar ice sheets requires studying the water properties at depth of the ice including
the water temperature and pressure using wireless sensor technology at multiple locations.
This can be achieved using Autonomous phase-sensitive Radio-Echo Sounder (ApRES)
radar instrument for retrieving geophysical data and geo-locating the position of a
subglacial sensor deployed in an ice sheet.
A realistic model of the subglacial environment is captured, taking different dielectric
properties of mediums that sensors may encounter into consideration, with a maximum
dielectric constant of 3.15, giving a maximum ice refraction of ~ 1.77, occurring at around
140m depth after which the refractive index remains constant. Attempts are made to
compare different ranging and localisation techniques for locating geospatial sensors (static
and/or mobile), incorporating TOA using FMCW radar techniques and phase-
sensitive signal processing algorithm.
Key system performance indicators were examined through link budget analysis and signal
processing using parameters for a phase-sensitive radar instrument that transmits a
frequency of 433 MHz and a bandwidth of 206 MHz, giving a SNR value of ~59 dB at a
maximum range of 1km and a range resolution of 69.3cm for ice medium. As expected,
range accuracy decreases with depth indicating that accuracy is a function of range, and at
the maximum range of 1km, the inaccuracy stands at 30cm, representing a significant error
margin. Improvement in range accuracy requires improvement in returned echo, antenna
gain and the SNR levels as these parameters are function of accuracy.
A proposal is made to improve design of helical antenna that can maintain orientation as it
moves through the glacial drainage. Preliminary lab tests with a 3-D printed prototype
indicate, maintaining antenna orientation (i.e. always pointing upwards) is achievable,
which will improve the signal strength and hence accuracy. Model of helical antenna
tailored for this application were designed in CST and MATLAB, extracting associated performance parameters.

Use of newly developed radar technique applied to subglacial application, amalgamated with positioning algorithm to achieve precise geospatial sensor localisation, enabling data retrieval via wireless technology.
Exploitation Route Develop GUI to determine signal deviation from selected performance parameters.

Develop robust antenna system that improves the quality of the signal strength.
Sectors Aerospace, Defence and Marine