Monday, April 22, 2019, 12:15PM - 1:15PM
Speaker
Ethan Welty
Location:
SEEC room S228
Topic
Cameras pointed at glaciers: Extracting precise high-frequency glacier observations from time-lapse photography
Abstract
Cameras are the inseparable sidekicks of field scientists everywhere. Although not intended for precise measurement, cameras are capable of such, provided they are properly calibrated. I present a suite of methods for precisely recovering position and time from photographs, so that they may be analyzed alongside other spatial and temporal data. The methods are tested on a vast archive of time-lapse photographs from Alaska’s Columbia Glacier.
A novel feature tracking algorithm (based on particle filtering theory) is then applied to 33,000 Columbia Glacier time-lapse photographs to recover detailed glacier velocities, their associated uncertainties, and corresponding strain rates at 3-day intervals over a 13-year period, providing an unprecedented look at the seasonal and sub-seasonal variability of tidewater glacier dynamics over long time scales. This image processing pipeline has been published as open-source software and awaits more test cases, both within and beyond glaciology.
Audience
Free and open to the public.