Preprints
https://doi.org/10.5194/gi-2018-28
https://doi.org/10.5194/gi-2018-28
27 Jul 2018
 | 27 Jul 2018
Status: this preprint was under review for the journal GI but the revision was not accepted.

PyTrx: A Python toolbox for deriving velocities, surface areas and line measurements from oblique imagery in glacial environments

Penelope How, Nicholas R. J. Hulton, and Lynne Buie

Abstract. Terrestrial time-lapse photogrammetry is a rapidly growing method for deriving measurements from glacial environments because it provides high spatio-temporal resolution records of change. However, glacial photogrammetry toolboxes are limited currently. Without prior knowledge in photogrammetry and computer coding, they are used primarily to calculate ice flow velocities or to serve as qualitative records. PyTrx (available at https://github.com/PennyHow/PyTrx) is presented here as a Python-alternative toolbox to widen the range of photogrammetry toolboxes on offer to the glaciology community. The toolbox holds core photogrammetric functions for point seeding, feature-tracking, image registration, and georectification (using a planar projective transformation model). In addition, PyTrx facilitates areal and line measurements, which can be detected from imagery using either an automated or manual approach. Examples of PyTrx's applications are demonstrated using time-lapse imagery from Kronebreen and Tunabreen, two tidewater glaciers in Svalbard. Products from these applications include ice flow velocities, surface areas of supraglacial lakes and meltwater plumes, and glacier terminus profiles.

Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this preprint. The responsibility to include appropriate place names lies with the authors.
Penelope How, Nicholas R. J. Hulton, and Lynne Buie
 
Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
 
Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
Penelope How, Nicholas R. J. Hulton, and Lynne Buie
Penelope How, Nicholas R. J. Hulton, and Lynne Buie

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Latest update: 18 May 2024
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Short summary
Terrestrial photogrammetry is the approach by which measurements are derived from images. It is a rapidly growing method in glaciology, providing detailed records of glacier change. However, glacial photogrammetry toolboxes are limited currently. PyTrx (freely available online) has been developed here as a Python-alternative toolbox with wider capabilities for deriving velocities, areas, and line measurements. Examples are presented throughout using time-lapse imagery from glaciers in Svalbard.