Leveraging Deep Neural Networks to Map Caribou Lichen in High-Resolution Satellite Images Based on a Small-Scale, Noisy UAV-Derived Map

Lichen is an important food source for caribou in Canada. Lichen mapping using remote sensing (RS) images could be a challenging task, however, as lichens generally appear in unevenly distributed, small patches, and could resemble surficial features. Moreover, collecting lichen labeled data (referen...

Full description

Bibliographic Details
Main Authors: Shahab Jozdani, Dongmei Chen, Wenjun Chen, Sylvain G. Leblanc, Christian Prévost, Julie Lovitt, Liming He, Brian A. Johnson
Format: Article
Language:English
Published: MDPI AG 2021-07-01
Series:Remote Sensing
Subjects:
Online Access:https://www.mdpi.com/2072-4292/13/14/2658
_version_ 1797526154162208768
author Shahab Jozdani
Dongmei Chen
Wenjun Chen
Sylvain G. Leblanc
Christian Prévost
Julie Lovitt
Liming He
Brian A. Johnson
author_facet Shahab Jozdani
Dongmei Chen
Wenjun Chen
Sylvain G. Leblanc
Christian Prévost
Julie Lovitt
Liming He
Brian A. Johnson
author_sort Shahab Jozdani
collection DOAJ
description Lichen is an important food source for caribou in Canada. Lichen mapping using remote sensing (RS) images could be a challenging task, however, as lichens generally appear in unevenly distributed, small patches, and could resemble surficial features. Moreover, collecting lichen labeled data (reference data) is expensive, which restricts the application of many robust supervised classification models that generally demand a large quantity of labeled data. The goal of this study was to investigate the potential of using a very-high-spatial resolution (1-cm) lichen map of a small sample site (e.g., generated based on a single UAV scene and using field data) to train a subsequent classifier to map caribou lichen over a much larger area (~0.04 km<sup>2</sup> vs. ~195 km<sup>2</sup>) and a lower spatial resolution image (in this case, a 50-cm WorldView-2 image). The limited labeled data from the sample site were also partially noisy due to spatial and temporal mismatching issues. For this, we deployed a recently proposed <i>Teacher-Student</i> semi-supervised learning (SSL) approach (based on U-Net and U-Net++ networks) involving unlabeled data to assist with improving the model performance. Our experiments showed that it was possible to scale-up the UAV-derived lichen map to the WorldView-2 scale with reasonable accuracy (overall accuracy of 85.28% and F1-socre of 84.38%) without collecting any samples directly in the WorldView-2 scene. We also found that our noisy labels were partially beneficial to the SSL robustness because they improved the false positive rate compared to the use of a cleaner training set directly collected within the same area in the WorldView-2 image. As a result, this research opens new insights into how current very high-resolution, small-scale caribou lichen maps can be used for generating more accurate large-scale caribou lichen maps from high-resolution satellite imagery.
first_indexed 2024-03-10T09:26:08Z
format Article
id doaj.art-ecf5100189f945cdadf87f57afce481c
institution Directory Open Access Journal
issn 2072-4292
language English
last_indexed 2024-03-10T09:26:08Z
publishDate 2021-07-01
publisher MDPI AG
record_format Article
series Remote Sensing
spelling doaj.art-ecf5100189f945cdadf87f57afce481c2023-11-22T04:50:31ZengMDPI AGRemote Sensing2072-42922021-07-011314265810.3390/rs13142658Leveraging Deep Neural Networks to Map Caribou Lichen in High-Resolution Satellite Images Based on a Small-Scale, Noisy UAV-Derived MapShahab Jozdani0Dongmei Chen1Wenjun Chen2Sylvain G. Leblanc3Christian Prévost4Julie Lovitt5Liming He6Brian A. Johnson7Department of Geography and Planning, Queen’s University, Kingston, ON K7L 3N6, CanadaDepartment of Geography and Planning, Queen’s University, Kingston, ON K7L 3N6, CanadaCanada Centre for Remote Sensing, Natural Resources Canada, 560 Rochester Street, Ottawa, ON K1S 5K2, CanadaCanada Centre for Remote Sensing, Natural Resources Canada, 560 Rochester Street, Ottawa, ON K1S 5K2, CanadaCanada Centre for Remote Sensing, Natural Resources Canada, 560 Rochester Street, Ottawa, ON K1S 5K2, CanadaCanada Centre for Remote Sensing, Natural Resources Canada, 560 Rochester Street, Ottawa, ON K1S 5K2, CanadaCanada Centre for Remote Sensing, Natural Resources Canada, 560 Rochester Street, Ottawa, ON K1S 5K2, CanadaNatural Resources and Ecosystem Services Area, Institute for Global Environmental Strategies, 2108-1 Kamiyamaguchi, Hayama, Kanagawa 240-0115, JapanLichen is an important food source for caribou in Canada. Lichen mapping using remote sensing (RS) images could be a challenging task, however, as lichens generally appear in unevenly distributed, small patches, and could resemble surficial features. Moreover, collecting lichen labeled data (reference data) is expensive, which restricts the application of many robust supervised classification models that generally demand a large quantity of labeled data. The goal of this study was to investigate the potential of using a very-high-spatial resolution (1-cm) lichen map of a small sample site (e.g., generated based on a single UAV scene and using field data) to train a subsequent classifier to map caribou lichen over a much larger area (~0.04 km<sup>2</sup> vs. ~195 km<sup>2</sup>) and a lower spatial resolution image (in this case, a 50-cm WorldView-2 image). The limited labeled data from the sample site were also partially noisy due to spatial and temporal mismatching issues. For this, we deployed a recently proposed <i>Teacher-Student</i> semi-supervised learning (SSL) approach (based on U-Net and U-Net++ networks) involving unlabeled data to assist with improving the model performance. Our experiments showed that it was possible to scale-up the UAV-derived lichen map to the WorldView-2 scale with reasonable accuracy (overall accuracy of 85.28% and F1-socre of 84.38%) without collecting any samples directly in the WorldView-2 scene. We also found that our noisy labels were partially beneficial to the SSL robustness because they improved the false positive rate compared to the use of a cleaner training set directly collected within the same area in the WorldView-2 image. As a result, this research opens new insights into how current very high-resolution, small-scale caribou lichen maps can be used for generating more accurate large-scale caribou lichen maps from high-resolution satellite imagery.https://www.mdpi.com/2072-4292/13/14/2658remote sensinglichen mappingdeep learningsemi-supervised learningteacher-student learningWorldView-2
spellingShingle Shahab Jozdani
Dongmei Chen
Wenjun Chen
Sylvain G. Leblanc
Christian Prévost
Julie Lovitt
Liming He
Brian A. Johnson
Leveraging Deep Neural Networks to Map Caribou Lichen in High-Resolution Satellite Images Based on a Small-Scale, Noisy UAV-Derived Map
Remote Sensing
remote sensing
lichen mapping
deep learning
semi-supervised learning
teacher-student learning
WorldView-2
title Leveraging Deep Neural Networks to Map Caribou Lichen in High-Resolution Satellite Images Based on a Small-Scale, Noisy UAV-Derived Map
title_full Leveraging Deep Neural Networks to Map Caribou Lichen in High-Resolution Satellite Images Based on a Small-Scale, Noisy UAV-Derived Map
title_fullStr Leveraging Deep Neural Networks to Map Caribou Lichen in High-Resolution Satellite Images Based on a Small-Scale, Noisy UAV-Derived Map
title_full_unstemmed Leveraging Deep Neural Networks to Map Caribou Lichen in High-Resolution Satellite Images Based on a Small-Scale, Noisy UAV-Derived Map
title_short Leveraging Deep Neural Networks to Map Caribou Lichen in High-Resolution Satellite Images Based on a Small-Scale, Noisy UAV-Derived Map
title_sort leveraging deep neural networks to map caribou lichen in high resolution satellite images based on a small scale noisy uav derived map
topic remote sensing
lichen mapping
deep learning
semi-supervised learning
teacher-student learning
WorldView-2
url https://www.mdpi.com/2072-4292/13/14/2658
work_keys_str_mv AT shahabjozdani leveragingdeepneuralnetworkstomapcariboulicheninhighresolutionsatelliteimagesbasedonasmallscalenoisyuavderivedmap
AT dongmeichen leveragingdeepneuralnetworkstomapcariboulicheninhighresolutionsatelliteimagesbasedonasmallscalenoisyuavderivedmap
AT wenjunchen leveragingdeepneuralnetworkstomapcariboulicheninhighresolutionsatelliteimagesbasedonasmallscalenoisyuavderivedmap
AT sylvaingleblanc leveragingdeepneuralnetworkstomapcariboulicheninhighresolutionsatelliteimagesbasedonasmallscalenoisyuavderivedmap
AT christianprevost leveragingdeepneuralnetworkstomapcariboulicheninhighresolutionsatelliteimagesbasedonasmallscalenoisyuavderivedmap
AT julielovitt leveragingdeepneuralnetworkstomapcariboulicheninhighresolutionsatelliteimagesbasedonasmallscalenoisyuavderivedmap
AT liminghe leveragingdeepneuralnetworkstomapcariboulicheninhighresolutionsatelliteimagesbasedonasmallscalenoisyuavderivedmap
AT brianajohnson leveragingdeepneuralnetworkstomapcariboulicheninhighresolutionsatelliteimagesbasedonasmallscalenoisyuavderivedmap