NWT RESEARCH DATABASE

Tags: physical sciences, hydrology, engineering, remote sensing, snow water equivalence

Objective(s): To continue to develop the ability to estimate tundra snow water equivalent using high resolution spaceborne sensors.

Project Description: New high resolution Ku- and Ka-band synthetic aperture radar (SAR) measurements are being proposed to measure tundra snow water equivalent (SWE) from future space-borne sensors, however further work is necessary to test the mission concept using airborne instruments that replicate the proposed satellite sensors. During the winter of 2012-2013 a research campaign at the Trail Valley Creek study site was conducted to test the SWE retrieval capability of an X- and Ku-band airborne SAR system. Preliminary results from this previous research campaign indicate that future airborne and spaceborne SAR SWE retrievals should use slightly different frequencies (Ku- and Ka-band) and more detailed measurements of the snow microstructure (grain size, density, layering) are necessary to improve SWE retrievals from SAR sensors. Therefore, to continue to develop the ability to estimate tundra SWE using high resolution spaceborne sensors, a 2 week field campaign to take place in March 2018, is being proposed to conduct snow surveys within the Trail Valley Creek watershed for comparison to airborne Ku- and Ka-band SAR measurements. An airborne radar system developed by the University of Massachusetts (UMass) is being proposed to be flown to collect backscatter measurements of snow covered tundra within the Trail Valley Creek watershed. This Ku- and Ka-band dual-frequency, interferometric SAR system was designed to emulate the configuration of a future satellite mission. These radars are low power systems, working at frequencies not typically used for communications, therefore, no harm to people, animals or communications in the vicinity of the aircraft is anticipated. The SAR system will be mounted onboard a Cessna 206 aircraft, and is being proposed to be flown at an altitude of ~4000 ft. above ground level. The 4000 ft. flight altitude will also minimize any disturbance to people or wildlife within the vicinity of the aircraft. The UMass system is proposed to fly along flight lines that will cover the northern portion of the Trail Valley Creek watershed. A total of 4 days of flying, every other day, are required to cover the entire study area with repeat passes. At the same time as the overflights of the UMass system, ground based snow surveys documenting the snow depth, water equivalent, density, grain size, and layering will be conducted by a team of researchers. The goal is measure the same snow properties using both manual survey techniques on the ground and via the airborne SAR sensors overhead, multiple times, over the course of several days. Results of this study will be published in academic journals once the analysis of the data is complete. In-addition, the research team is willing to provide a public talk to community members to provide more background information on the type of work that is being done, and to discuss the research with interested parties. The researchers participating in this campaign will provide Aurora Research Institute (ARI) with a copy of any published journals/articles/thesis related to this campaign and are willing to present an overview on the research objectives of this campaign at community meetings or community science fairs or any other suitable venues as suggested by the Aurora Research Institute. The data collected during this campaign will also be made available online as part of the Open Data initiative of the Canadian government with details to be provided to the ARI when they are posted. The fieldwork for this study will be conducted from March 4, 2018 to March 17, 2018.