PhD Project

The application of millimetre wave radar to the study of volcano-glacier interactions and ice-ocean interactions in conditions of reduced visibility.’

Supervisors: Dr Duncan Robertson, Dr David Macfarlane, Prof. Doug Benn (University of St Andrews), Prof. Brice Rea, Dr Matteo Spagnolo (University of Aberdeen) and Prof. Luca De Siena (Johannes Gutenberg University, Mainz).

Millimetre wave radar is a special type of imaging device that can see through most weather conditions and is portable in the field allowing rapid deployment for monitoring purposes. It essentially offers a compromise between high resolution imaging and propagation through atmospheric obscurants. The millimetre-wave group at the University of St Andrews have developed AVTIS (the All-weather Volcano Topography Imaging Sensor) for monitoring volcanic lava domes [1]. My PhD will develop this instrument for glacier remote sensing focussing on two case studies: ice-ocean interactions and glacio-volcanism.

AVTIS scanning at Rhone Glacier. Picture taken by W.D. Harcourt.

AVTIS is a real-aperture radar meaning it transmits a beam and measures the backscatter from a surface or target. Terrain backscatter is dependent on the dielectric properties of the material, the surface roughness and the local incidence angle. The Radar Cross Section (RCS) is a measure that quantifies the total backscatter from each of these components and the Normalised RCS (NRCS) corrects for changes in the beam footprint. I will quantify the NRCS of glacial ice at 94 GHz in order to provide a solid foundation for deployment of the system at other glaciers. This will also help to derive algorithms for terrain classification.

These improvements in the design and analysis of millimetre wave radar will be used to deploy AVTIS at glaciers in order to monitor processes occurring at the ice-ocean interface and where volcanoes sit below an ice mass. The process of calving is still not fully understood and new insights have been provided by high resolution ground based sensors such as UAV photogrammetry and time-lapse cameras. However, these cannot operate in adverse weather conditions. Thus, ground-based radars offer a new opportunity to obtain high spatial and temporal resolution measurements of a glacier which can be used to understand glacier processes.

My research questions are:

  • What are the scattering properties of glacial ice at millimetre wavelengths?
  • To what extent does the beam footprint degrade the radar performance and can this be corrected for?
  • What information can be gained by using a millimetre-wave radar to study glacier-volcano and ice-ocean interactions.

References

[1] Macfarlane et al. (2013). Topographic and thermal mapping of volcanic terrain using the AVTIS ground-based 94-GHz dual-mode radar/radiometric imager, IEEE Transactions on Geoscience and Remote Sensing, 51, 455-472, doi: 10.1109/TGRS.2012.2202667.