A Methodological Framework for Mapping Canopy Cover Using ICESat-2 in the Southern USA
NASA’s Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) provides exceptional opportunities for characterizing the structure of ecosystems through the acquisition of along-track, three-dimensional observations. Focusing on canopy cover as a fundamental parameter for assessing forest conditions,...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-03-01
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| Series: | Remote Sensing |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2072-4292/15/6/1548 |
| _version_ | 1797609246302404608 |
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| author | Lana L. Narine Sorin C. Popescu Lonesome Malambo |
| author_facet | Lana L. Narine Sorin C. Popescu Lonesome Malambo |
| author_sort | Lana L. Narine |
| collection | DOAJ |
| description | NASA’s Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) provides exceptional opportunities for characterizing the structure of ecosystems through the acquisition of along-track, three-dimensional observations. Focusing on canopy cover as a fundamental parameter for assessing forest conditions, the overall goal of this study was to establish a framework for generating a gridded 30 m canopy cover product with ICESat-2. Specifically, our objectives were to (1) Determine and compare ICESat-2-derived canopy cover with airborne lidar-derived and the 2016 National Land Cover Database (NLCD) cover product estimates, and (2) Evaluate a methodology for wall-to-wall mapping of canopy cover. Using two Southern US sites, the Sam Houston National Forest (SHNF) in south-east Texas and the Solon Dixon Forestry Education Center (SDFEC) in southern Alabama, four measures of canopy cover estimated with ICESat-2′s Land-Vegetation Along-Track Product, or ATL08, were evaluated at the 30 m pixel scale. Comparisons were made using spatially coinciding NLCD pixels and airborne lidar-derived reference canopy cover. A suite of Landsat and Landsat-derived parameters were then used as predictors to model and map each measure of canopy cover with Random Forests (RF), and their accuracies were assessed and compared. Correlations (r) between ICESat-2-derived and airborne lidar canopy cover at the pixel scale ranged from 0.57 to 0.78, and R<sup>2</sup> up to 0.81 was produced between NLCD and ICESat-2-derived canopy cover. RF models developed for extrapolating ICESat-2-derived canopy cover estimate yielded R<sup>2</sup> values between 0.50 and 0.61 (RMSEs between 16% and 20%) when evaluated with airborne lidar-derived canopy cover. With a demonstrated capability of ICESat-2 to estimate vegetation biophysical parameters, the findings serve to support the spatially comprehensive mapping of other vegetation attributes, especially forest aboveground biomass, and contribute to the development of an up-to-date gridded canopy cover product. |
| first_indexed | 2024-03-11T05:57:50Z |
| format | Article |
| id | doaj.art-fdd4419a3a6e449a822ff253b2eacf3b |
| institution | Directory Open Access Journal |
| issn | 2072-4292 |
| language | English |
| last_indexed | 2024-03-11T05:57:50Z |
| publishDate | 2023-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Remote Sensing |
| spelling | doaj.art-fdd4419a3a6e449a822ff253b2eacf3b2023-11-17T13:38:41ZengMDPI AGRemote Sensing2072-42922023-03-01156154810.3390/rs15061548A Methodological Framework for Mapping Canopy Cover Using ICESat-2 in the Southern USALana L. Narine0Sorin C. Popescu1Lonesome Malambo2College of Forestry, Wildlife and Environment, Auburn University, Auburn, AL 36849, USADepartment of Ecology and Conservation Biology, Texas A&M University, College Station, TX 77843, USADepartment of Ecology and Conservation Biology, Texas A&M University, College Station, TX 77843, USANASA’s Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) provides exceptional opportunities for characterizing the structure of ecosystems through the acquisition of along-track, three-dimensional observations. Focusing on canopy cover as a fundamental parameter for assessing forest conditions, the overall goal of this study was to establish a framework for generating a gridded 30 m canopy cover product with ICESat-2. Specifically, our objectives were to (1) Determine and compare ICESat-2-derived canopy cover with airborne lidar-derived and the 2016 National Land Cover Database (NLCD) cover product estimates, and (2) Evaluate a methodology for wall-to-wall mapping of canopy cover. Using two Southern US sites, the Sam Houston National Forest (SHNF) in south-east Texas and the Solon Dixon Forestry Education Center (SDFEC) in southern Alabama, four measures of canopy cover estimated with ICESat-2′s Land-Vegetation Along-Track Product, or ATL08, were evaluated at the 30 m pixel scale. Comparisons were made using spatially coinciding NLCD pixels and airborne lidar-derived reference canopy cover. A suite of Landsat and Landsat-derived parameters were then used as predictors to model and map each measure of canopy cover with Random Forests (RF), and their accuracies were assessed and compared. Correlations (r) between ICESat-2-derived and airborne lidar canopy cover at the pixel scale ranged from 0.57 to 0.78, and R<sup>2</sup> up to 0.81 was produced between NLCD and ICESat-2-derived canopy cover. RF models developed for extrapolating ICESat-2-derived canopy cover estimate yielded R<sup>2</sup> values between 0.50 and 0.61 (RMSEs between 16% and 20%) when evaluated with airborne lidar-derived canopy cover. With a demonstrated capability of ICESat-2 to estimate vegetation biophysical parameters, the findings serve to support the spatially comprehensive mapping of other vegetation attributes, especially forest aboveground biomass, and contribute to the development of an up-to-date gridded canopy cover product.https://www.mdpi.com/2072-4292/15/6/1548ICESat-2ATL08canopy cover |
| spellingShingle | Lana L. Narine Sorin C. Popescu Lonesome Malambo A Methodological Framework for Mapping Canopy Cover Using ICESat-2 in the Southern USA Remote Sensing ICESat-2 ATL08 canopy cover |
| title | A Methodological Framework for Mapping Canopy Cover Using ICESat-2 in the Southern USA |
| title_full | A Methodological Framework for Mapping Canopy Cover Using ICESat-2 in the Southern USA |
| title_fullStr | A Methodological Framework for Mapping Canopy Cover Using ICESat-2 in the Southern USA |
| title_full_unstemmed | A Methodological Framework for Mapping Canopy Cover Using ICESat-2 in the Southern USA |
| title_short | A Methodological Framework for Mapping Canopy Cover Using ICESat-2 in the Southern USA |
| title_sort | methodological framework for mapping canopy cover using icesat 2 in the southern usa |
| topic | ICESat-2 ATL08 canopy cover |
| url | https://www.mdpi.com/2072-4292/15/6/1548 |
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