Laser altimeter canopy height profiles Methods and validation for closed-canopy, broadleaf forests.
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| Title: | Laser altimeter canopy height profiles Methods and validation for closed-canopy, broadleaf forests. |
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| Authors: | Harding, D.J., Lefsky, M.A., Parker, G.G., Blair, J.B. |
| Source: | Remote Sensing of Environment. Jun2001, Vol. 76 Issue 3, p283. 13p. 3 Diagrams, 5 Charts, 17 Graphs. |
| Subjects: | Forest canopies, Airborne profile recorder |
| Abstract: | Waveform-recording laser altimeter observations of vegetated landscapes provide a time-resolved measure of laser pulse backscatter energy from canopy surfaces and the underlying ground. Airborne laser altimeter waveform data was acquired using the Scanning Lidar Imager of Canopies by Echo Recovery (SLICER) for a successional sequence of four, closed-canopy, deciduous forest stands in eastern Maryland. The four stands were selected so as to include a range of canopy structures of importance to forest ecosystem function, including variation in the height and roughness of the outermost canopy surface and the vertical organization of canopy stories and gaps. The character of the SLICER backscatter signal is described and a method is developed that accounts for occlusion of the laser energy by canopy surfaces, transforming the backscatter signal to a canopy height profile (CHP) that quantitatively represents the relative vertical distribution of canopy surface area. The transformation applies increased weighting to the backscatter amplitude as a function of closure through the canopy and assumes a horizontally random distribution of the canopy components. SLICER CHPs, averaged over areas of overlap where altimeter ground tracks intersect, are shown to be highly reproducible. CHP transects across the four stands reveal spatial variations in vegetation, at the scale of the individual 10-m-diameter laser footprints, within and between stands. Averaged SLICER CHPs are compared to analogous height profile results derived from ground-based sightings to plant intercepts measured on plots within the four stands. The plots were located on the segments of the altimeter ground tracks from which averaged SLICER CHPs were derived, and the ground observations were acquired within 2 weeks of the SLICER data acquisition to minimize temporal change. The differences in canopy structure between the four stands is similarly described by the SLICER and ground-based CHP results. However,... [ABSTRACT FROM AUTHOR] |
| Copyright of Remote Sensing of Environment is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 8760573 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Laser altimeter canopy height profiles Methods and validation for closed-canopy, broadleaf forests. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Harding%2C+D%2EJ%2E%22">Harding, D.J.</searchLink><br /><searchLink fieldCode="AR" term="%22Lefsky%2C+M%2EA%2E%22">Lefsky, M.A.</searchLink><br /><searchLink fieldCode="AR" term="%22Parker%2C+G%2EG%2E%22">Parker, G.G.</searchLink><br /><searchLink fieldCode="AR" term="%22Blair%2C+J%2EB%2E%22">Blair, J.B.</searchLink> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Remote+Sensing+of+Environment%22">Remote Sensing of Environment</searchLink>. Jun2001, Vol. 76 Issue 3, p283. 13p. 3 Diagrams, 5 Charts, 17 Graphs. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Forest+canopies%22">Forest canopies</searchLink><br /><searchLink fieldCode="DE" term="%22Airborne+profile+recorder%22">Airborne profile recorder</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Waveform-recording laser altimeter observations of vegetated landscapes provide a time-resolved measure of laser pulse backscatter energy from canopy surfaces and the underlying ground. Airborne laser altimeter waveform data was acquired using the Scanning Lidar Imager of Canopies by Echo Recovery (SLICER) for a successional sequence of four, closed-canopy, deciduous forest stands in eastern Maryland. The four stands were selected so as to include a range of canopy structures of importance to forest ecosystem function, including variation in the height and roughness of the outermost canopy surface and the vertical organization of canopy stories and gaps. The character of the SLICER backscatter signal is described and a method is developed that accounts for occlusion of the laser energy by canopy surfaces, transforming the backscatter signal to a canopy height profile (CHP) that quantitatively represents the relative vertical distribution of canopy surface area. The transformation applies increased weighting to the backscatter amplitude as a function of closure through the canopy and assumes a horizontally random distribution of the canopy components. SLICER CHPs, averaged over areas of overlap where altimeter ground tracks intersect, are shown to be highly reproducible. CHP transects across the four stands reveal spatial variations in vegetation, at the scale of the individual 10-m-diameter laser footprints, within and between stands. Averaged SLICER CHPs are compared to analogous height profile results derived from ground-based sightings to plant intercepts measured on plots within the four stands. The plots were located on the segments of the altimeter ground tracks from which averaged SLICER CHPs were derived, and the ground observations were acquired within 2 weeks of the SLICER data acquisition to minimize temporal change. The differences in canopy structure between the four stands is similarly described by the SLICER and ground-based CHP results. However,... [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Remote Sensing of Environment is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1016/S0034-4257(00)00210-8 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 13 StartPage: 283 Subjects: – SubjectFull: Forest canopies Type: general – SubjectFull: Airborne profile recorder Type: general Titles: – TitleFull: Laser altimeter canopy height profiles Methods and validation for closed-canopy, broadleaf forests. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Harding, D.J. – PersonEntity: Name: NameFull: Lefsky, M.A. – PersonEntity: Name: NameFull: Parker, G.G. – PersonEntity: Name: NameFull: Blair, J.B. IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 06 Text: Jun2001 Type: published Y: 2001 Identifiers: – Type: issn-print Value: 00344257 Numbering: – Type: volume Value: 76 – Type: issue Value: 3 Titles: – TitleFull: Remote Sensing of Environment Type: main |
| ResultId | 1 |
