Ph.D. position: T2-PhD4 Airborne InSAR to monitor permafrost thaw near linear infrastructure

Posted: July 25, 2019

Anticipated start: Spring 2020 (flexible)

Supervisory team: Dr. Bernhard Rabus, Dr. Fabrice Calmels (Yukon Research Center)

Internship: Department of Infrastructure, Government of the Northwest Territories 

Research description

Spaceborne InSAR has already demonstrated is a powerful tool to measure seasonal and long-term active layer dynamics at medium resolution (around 20m) and land-scape scale (several 100 km extents). However, detecting the effects of permafrost change on infrastructure integrity by evaluating effective material stress from spatial displacement gradients, requires high-resolution SAR data (1m or better). For concentrated infrastructure such as settlements or mine pits, high-resolution spaceborne InSAR data acquired in spotlight mode (about 10 km extent) is suitable. Nonetheless, for monitoring of extended linear infrastructure such as roads, pipelines, dikes and coastline, acquisition of space-borne high-resolution SAR data becomes quickly inefficient and expensive.

In this project, we will demonstrate the scientific and competitive usefulness of repeat pass InSAR observations with an airborne sensor (SlimSAR) for measuring linear infrastructure integrity affected by permafrost dynamics and degradation underneath or near the infrastructure. Airborne InSAR offers the possibility to observe two-dimensional permafrost displacement allowing to resolve vertical and horizontal displacements separately; achieved by acquiring matching SAR data along the infrastructure also from the other side on the return flight (back and forth). Atmospheric phase artifacts can also be usually neglected in airborne InSAR data, while they are generally significant for spaceborne data. On the downside, airborne SAR lacks the convenient regular temporal repeat pass of the space-borne data. Also, phase artifacts from non-linear motion are significantly more severe for the airborne SAR, which require sophisticated motion compensation MOCOMP algorithms to remove from interferograms. 

The airborne SAR system used for this project is dual frequency and unique in acquiring polarimetric L- and single-pass X-band data simultaneously on the same flight. For repeat pass InSAR data measuring permafrost displacement this enables efficient removal of the topographic phase as well as the use of a variety of novel MOCOMP algorithms. The bulk of the proposed project consists of testing and optimizing different MOCOMP types to achieve the best possible accuracy for the displacement measurements.

The project will use medium resolution spaceborne InSAR for reconnaissance of interesting segments of linear infrastructure. Selected high-resolution spaceborne InSAR over N-S trending infrastructure will be compared with near-simultaneous airborne InSAR data to quantify the quality of infrastructure integrity maps achievable with the airborne system.

Key research tasks

  • SlimSAR airborne campaigns planned and executed in spring and fall to acquire two-directional InSAR datasets along the AlCan Highway; sites selection with partners
  • Post-processing of the acquired data to maximise InSAR quality, application of motion compensation algorithms, refinements on positioning systems
  • Development of methods for phase-correcting SlimSAR repeat-pass interferograms
  • Displacement gradient maps generated. Compare SlimSAR accuracy with spaceborne InSAR, manuscript for IEEE Transactions on Geoscience and Remote Sensing

Your profile

  • Passionate research interest and a background in remote sensing
  • Solid programming skills (including C++ and Python)
  • Strong scientific writing skills and high motivation to produce publishable results
  • A very good command of English, both spoken and written. Internet-based TOEFL (93 with minimum of 20 in each category), Paper-based TOEFL (580 and TWE 5), IELTS academic (overall band score of 7.0 of the academic (NOT general) test with a minimum of 6.5 in each section).

What we offer

  • Fully-funded research for 12 months per year, starting at CAD$ 24,000/yr and increasing up to CAD$ 30,000/yr, for full concentration on research and network activities. Through the School of Engineering Science's Graduate Fellowship (GF) and/or Teaching Assistantship Program (TA), applicants generally receive an additional CAD$13,000/yr or more (this additional amount alone is sufficient to cover tuition fees).
  • Internship opportunities especially with partners in northern locations
  • A dynamic and multidisciplinary learning environment
  • State-of-the-art equipment and facilities

To submit an application: Send Dr. Bernhard Rabus ( your letter of interest, CV, copy of transcript(s), and contact information for 3 references. Applications will be reviewed as they are received. All applications will be reviewed by the selection committee with respect to academic qualifications and integration within the network through the PermafrostNet lens on equity, diversity and inclusion. The position will remain open until filled. We thank all applicants for their interest, however, only those individuals selected for an interview will be contacted.