Calving fronts and where to find them: a benchmark dataset and methodology for automatic glacier calving front extraction from synthetic aperture radar imagery

<p>Exact information on the calving front positions of marine- or lake-terminating glaciers is a fundamental glacier variable for analyzing ongoing glacier change processes and assessing other variables like frontal ablation rates. In recent years, researchers started implementing algorithms t...

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Main Authors: N. Gourmelon, T. Seehaus, M. Braun, A. Maier, V. Christlein
Format: Article
Language:English
Published: Copernicus Publications 2022-09-01
Series:Earth System Science Data
Online Access:https://essd.copernicus.org/articles/14/4287/2022/essd-14-4287-2022.pdf
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author N. Gourmelon
T. Seehaus
M. Braun
A. Maier
V. Christlein
author_facet N. Gourmelon
T. Seehaus
M. Braun
A. Maier
V. Christlein
author_sort N. Gourmelon
collection DOAJ
description <p>Exact information on the calving front positions of marine- or lake-terminating glaciers is a fundamental glacier variable for analyzing ongoing glacier change processes and assessing other variables like frontal ablation rates. In recent years, researchers started implementing algorithms that can automatically detect the calving fronts on satellite imagery. Most studies use optical images, as calving fronts are often easy to distinguish in these images due to the sufficient spatial resolution and the presence of different spectral bands, allowing the separation of ice features. However, detecting calving fronts on synthetic aperture radar (SAR) images is highly desirable, as SAR images can also be acquired during the polar night and are independent of weather conditions (e.g., cloud cover), facilitating year-round monitoring worldwide. In this paper, we present a benchmark dataset <span class="cit" id="xref_paren.1">(<a href="#bib1.bibx28">Gourmelon et al.</a>, <a href="#bib1.bibx28">2022</a><a href="#bib1.bibx28">b</a>)</span> of SAR images from multiple regions of the globe with corresponding manually defined labels providing information on the position of the calving front (<span class="uri">https://doi.org/10.1594/PANGAEA.940950</span>). With this dataset, different approaches for the detection of glacier calving fronts can be implemented, tested, and their performance fairly compared so that the most effective approach can be determined. The dataset consists of 681 samples, making it large enough to train deep learning segmentation models. It is the first dataset to provide long-term glacier calving front information from multi-mission data. As the dataset includes glaciers from Antarctica, Greenland, and Alaska, the wide applicability of models trained and tested on this dataset is ensured. The test set is independent of the training set so that the generalization capabilities of the models can be evaluated. We provide two sets of labels: one binary segmentation label to discern the calving front from the background, and one label for multi-class segmentation of different landscape classes. Unlike other calving front datasets, the presented dataset contains not only the labels but also the corresponding preprocessed and geo-referenced SAR images as PNG files. The ease of access to the dataset will allow scientists from other fields, such as data science, to contribute their expertise. With this benchmark dataset, we enable comparability between different front detection algorithms and improve the reproducibility of front detection studies. Moreover, we present one baseline model for each kind of label type. Both models are based on the U-Net, one of the most popular deep learning segmentation architectures. In the following two post-processing procedures, the segmentation results are converted into 1-pixel-wide front delineations. By providing both types of labels, both approaches can be used to address the problem. To assess the performance of different models, we suggest first reviewing the segmentation results using the recall, precision, <span class="inline-formula"><i>F</i><sub>1</sub></span> score, and the Jaccard index. Second, the front delineation can be evaluated by calculating the mean distance error to the labeled front. The presented vanilla models provide a baseline of 150 m <span class="inline-formula">±</span> 24 m mean distance error for the Mapple Glacier in Antarctica and 840 m <span class="inline-formula">±</span> 84 m for the Columbia Glacier in Alaska, which has a more complex calving front, consisting of multiple sections, compared with a laterally well constrained, single calving front of Mapple Glacier.</p>
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spelling doaj.art-f964dbffb24c4df7b3ead211463389432022-12-22T03:14:23ZengCopernicus PublicationsEarth System Science Data1866-35081866-35162022-09-01144287431310.5194/essd-14-4287-2022Calving fronts and where to find them: a benchmark dataset and methodology for automatic glacier calving front extraction from synthetic aperture radar imageryN. Gourmelon0T. Seehaus1M. Braun2A. Maier3V. Christlein4Pattern Recognition Lab, Computer Science Department, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, GermanyInstitute of Geography, Department of Geography and Geosciences, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, GermanyInstitute of Geography, Department of Geography and Geosciences, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, GermanyPattern Recognition Lab, Computer Science Department, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, GermanyPattern Recognition Lab, Computer Science Department, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany<p>Exact information on the calving front positions of marine- or lake-terminating glaciers is a fundamental glacier variable for analyzing ongoing glacier change processes and assessing other variables like frontal ablation rates. In recent years, researchers started implementing algorithms that can automatically detect the calving fronts on satellite imagery. Most studies use optical images, as calving fronts are often easy to distinguish in these images due to the sufficient spatial resolution and the presence of different spectral bands, allowing the separation of ice features. However, detecting calving fronts on synthetic aperture radar (SAR) images is highly desirable, as SAR images can also be acquired during the polar night and are independent of weather conditions (e.g., cloud cover), facilitating year-round monitoring worldwide. In this paper, we present a benchmark dataset <span class="cit" id="xref_paren.1">(<a href="#bib1.bibx28">Gourmelon et al.</a>, <a href="#bib1.bibx28">2022</a><a href="#bib1.bibx28">b</a>)</span> of SAR images from multiple regions of the globe with corresponding manually defined labels providing information on the position of the calving front (<span class="uri">https://doi.org/10.1594/PANGAEA.940950</span>). With this dataset, different approaches for the detection of glacier calving fronts can be implemented, tested, and their performance fairly compared so that the most effective approach can be determined. The dataset consists of 681 samples, making it large enough to train deep learning segmentation models. It is the first dataset to provide long-term glacier calving front information from multi-mission data. As the dataset includes glaciers from Antarctica, Greenland, and Alaska, the wide applicability of models trained and tested on this dataset is ensured. The test set is independent of the training set so that the generalization capabilities of the models can be evaluated. We provide two sets of labels: one binary segmentation label to discern the calving front from the background, and one label for multi-class segmentation of different landscape classes. Unlike other calving front datasets, the presented dataset contains not only the labels but also the corresponding preprocessed and geo-referenced SAR images as PNG files. The ease of access to the dataset will allow scientists from other fields, such as data science, to contribute their expertise. With this benchmark dataset, we enable comparability between different front detection algorithms and improve the reproducibility of front detection studies. Moreover, we present one baseline model for each kind of label type. Both models are based on the U-Net, one of the most popular deep learning segmentation architectures. In the following two post-processing procedures, the segmentation results are converted into 1-pixel-wide front delineations. By providing both types of labels, both approaches can be used to address the problem. To assess the performance of different models, we suggest first reviewing the segmentation results using the recall, precision, <span class="inline-formula"><i>F</i><sub>1</sub></span> score, and the Jaccard index. Second, the front delineation can be evaluated by calculating the mean distance error to the labeled front. The presented vanilla models provide a baseline of 150 m <span class="inline-formula">±</span> 24 m mean distance error for the Mapple Glacier in Antarctica and 840 m <span class="inline-formula">±</span> 84 m for the Columbia Glacier in Alaska, which has a more complex calving front, consisting of multiple sections, compared with a laterally well constrained, single calving front of Mapple Glacier.</p>https://essd.copernicus.org/articles/14/4287/2022/essd-14-4287-2022.pdf
spellingShingle N. Gourmelon
T. Seehaus
M. Braun
A. Maier
V. Christlein
Calving fronts and where to find them: a benchmark dataset and methodology for automatic glacier calving front extraction from synthetic aperture radar imagery
Earth System Science Data
title Calving fronts and where to find them: a benchmark dataset and methodology for automatic glacier calving front extraction from synthetic aperture radar imagery
title_full Calving fronts and where to find them: a benchmark dataset and methodology for automatic glacier calving front extraction from synthetic aperture radar imagery
title_fullStr Calving fronts and where to find them: a benchmark dataset and methodology for automatic glacier calving front extraction from synthetic aperture radar imagery
title_full_unstemmed Calving fronts and where to find them: a benchmark dataset and methodology for automatic glacier calving front extraction from synthetic aperture radar imagery
title_short Calving fronts and where to find them: a benchmark dataset and methodology for automatic glacier calving front extraction from synthetic aperture radar imagery
title_sort calving fronts and where to find them a benchmark dataset and methodology for automatic glacier calving front extraction from synthetic aperture radar imagery
url https://essd.copernicus.org/articles/14/4287/2022/essd-14-4287-2022.pdf
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