-
T. B. Abbe and D. R. Montgomery.
Patterns and processes of wood debris accumulation in the Queets river basin, Washington.
Geomorphology,
51:81-107,
2003.
@article{RefWorks:786,
author={T. B. Abbe and D. R. Montgomery},
year={2003},
title={Patterns and processes of wood debris accumulation in the Queets river basin, Washington},
journal={Geomorphology},
volume={51},
pages={81-107}
}
-
Tomas Brandtberg,
Timothy A. Warner,
Rick E. Landenberger,
and James B. McGraw.
Detection and analysis of individual leaf-off tree crowns in small footprint, high sampling density lidar data from the eastern deciduous forest in North America.
rse,
85(3):290-303,
2003.
[WWW
] Keyword(s): Image processing,
Individual tree,
Lidar,
Remote sensing,
Species classification.
Abstract: |
Leaf-off individual trees in a deciduous forest in the eastern USA are detected and analysed in small footprint, high sampling density lidar data. The data were acquired February 1, 2001, using a SAAB TopEye laser profiling system, with a sampling density of approximately 12 returns per square meter. The sparse and complex configuration of the branches of the leaf-off forest provides sufficient returns to allow the detection of the trees as individual objects and to analyse their vertical structures. Initially, for the detection of the individual trees only, the lidar data are first inserted in a 2D digital image, with the height as the pixel value or brightness level. The empty pixels are interpolated, and height outliers are removed. Gaussian smoothing at different scales is performed to create a three-dimensional scale-space structure. Blob signatures based on second-order image derivatives are calculated, and then normalised so they can be compared at different scale-levels. The grey-level blobs with the strongest normalised signatures are selected within the scale-space structure. The support regions of the blobs are marked one-at-a-time in the segmentation result image with higher priority for stronger blobs. The segmentation results of six individual hectare plots are assessed by a computerised, objective method that makes use of a ground reference data set of the individual tree crowns. For analysis of individual trees, a subset of the original laser returns is selected within each tree crown region of the canopy reference map. Indices based on moments of the first four orders, maximum value and number of canopy and ground returns, are estimated. The indices are derived separately for height and laser reflectance of branches for the two echoes. Significant differences (p<0.05) are detected for numerous indices for three major native species groups: oaks (Quercus spp.), red maple (Acer rubrum) and yellow poplar (Liriodendron tuliperifera). Tree species classification results of different indices suggest a moderate to high degree of accuracy using single or multiple variables. Furthermore, the maximum tree height is compared to ground reference tree height for 48 sample trees and a 1.1-m standard error (R2=68% (adj.)) within the test-site is observed. |
@Article{brandtberg03,
author = {Tomas Brandtberg and Timothy A. Warner and Rick E. Landenberger and James B. McGraw},
title = {Detection and analysis of individual leaf-off tree crowns in small footprint, high sampling density lidar data from the eastern deciduous forest in North America},
journal = rse,
year = {2003},
volume = {85},
pages = {290-303},
number = {3},
url = {http://www.sciencedirect.com/science/article/B6V6V-47VSCC2-1/2/7d551fda030a61c85782063f85888642},
keyword = { Image processing; Individual tree; Lidar; Remote sensing; Species classification},
abstract = {Leaf-off individual trees in a deciduous forest in the eastern USA are detected and analysed in small footprint, high sampling density lidar data. The data were acquired February 1, 2001, using a SAAB TopEye laser profiling system, with a sampling density of approximately 12 returns per square meter. The sparse and complex configuration of the branches of the leaf-off forest provides sufficient returns to allow the detection of the trees as individual objects and to analyse their vertical structures. Initially, for the detection of the individual trees only, the lidar data are first inserted in a 2D digital image, with the height as the pixel value or brightness level. The empty pixels are interpolated, and height outliers are removed. Gaussian smoothing at different scales is performed to create a three-dimensional scale-space structure. Blob signatures based on second-order image derivatives are calculated, and then normalised so they can be compared at different scale-levels. The grey-level blobs with the strongest normalised signatures are selected within the scale-space structure. The support regions of the blobs are marked one-at-a-time in the segmentation result image with higher priority for stronger blobs. The segmentation results of six individual hectare plots are assessed by a computerised, objective method that makes use of a ground reference data set of the individual tree crowns. For analysis of individual trees, a subset of the original laser returns is selected within each tree crown region of the canopy reference map. Indices based on moments of the first four orders, maximum value and number of canopy and ground returns, are estimated. The indices are derived separately for height and laser reflectance of branches for the two echoes. Significant differences (p<0.05) are detected for numerous indices for three major native species groups: oaks (Quercus spp.), red maple (Acer rubrum) and yellow poplar (Liriodendron tuliperifera). Tree species classification results of different indices suggest a moderate to high degree of accuracy using single or multiple variables. Furthermore, the maximum tree height is compared to ground reference tree height for 48 sample trees and a 1.1-m standard error (R2=68% (adj.)) within the test-site is observed.},
}
-
D. R. Butler,
G. P. Malanson,
M. F. Bekker,
and L. M. Resler.
Lithologic, structural, and geomorphic controls on ribbon forest patterns in a glaciated mountain environment.
Geomorphology,
55(1-4):203-217,
2003.
@article{RefWorks:794,
author={D. R. Butler and G. P. Malanson and M. F. Bekker and L. M. Resler},
year={2003},
title={Lithologic, structural, and geomorphic controls on ribbon forest patterns in a glaciated mountain environment},
journal={Geomorphology},
volume={55},
number={1-4},
pages={203-217}
}
-
D.L.A Gaveau and R.A. Hill.
Quantifying canopy height underestimation by laser pulse penetration in small-footprint airborne laser scanning data..
cjrs,
29:650-657,
2003.
Abstract: |
There is a well-reported tendency for canopy height to be underestimated in small-footprint ALS data of coniferous woodland. This is commonly explained by a failure to record tree-tops because of insufficient ALS sampling density. This study examines the accuracy of canopy height estimates retrieved from small-footprint dual-return ALS data of broad-leaf woodland. A novel field sampling method was adopted to collect reference canopy upper surface measurements of known horizontal (x-, y-) and vertical (z-) position that had sub-metre accuracy. By investigating the z- differences between ALS and reference canopy measurements with matching x- and y- locations the effects of ALS sampling density were removed from the analysis. For raw point-sample ALS data, a negative bias was observed of 0.91 m for sample shrub canopies and 1.27 m for sample tree canopies. These results suggest that for broad-leaf woodland, a small-footprint laser pulse hitting the upper surface of a canopy often advances into the canopy before reflecting a signal strong enough to be detected by the scanner as a first-return. The depth of laser pulse penetration will vary with canopy structural characteristics and ALS device configuration. Interpolating the point-sample ALS canopy measurements into a grid-based Digital Canopy Height Model propagated the observed errors, resulting in a negative bias of 1.02 m for shrub canopies and 2.12 m for tree canopies. Here the sampling density in relation to canopy surface roughness was important. |
@Article{gaveau03,
author = {D.L.A Gaveau and R.A. Hill},
title = {Quantifying canopy height underestimation by laser pulse penetration in small-footprint airborne laser scanning data.},
journal = cjrs,
year = {2003},
volume = {29},
pages = {650-657},
number = {},
url = {},
keyword = {},
abstract = {There is a well-reported tendency for canopy height to be underestimated in small-footprint ALS data of coniferous woodland. This is commonly explained by a failure to record tree-tops because of insufficient ALS sampling density. This study examines the accuracy of canopy height estimates retrieved from small-footprint dual-return ALS data of broad-leaf woodland. A novel field sampling method was adopted to collect reference canopy upper surface measurements of known horizontal (x-, y-) and vertical (z-) position that had sub-metre accuracy. By investigating the z- differences between ALS and reference canopy measurements with matching x- and y- locations the effects of ALS sampling density were removed from the analysis. For raw point-sample ALS data, a negative bias was observed of 0.91 m for sample shrub canopies and 1.27 m for sample tree canopies. These results suggest that for broad-leaf woodland, a small-footprint laser pulse hitting the upper surface of a canopy often advances into the canopy before reflecting a signal strong enough to be detected by the scanner as a first-return. The depth of laser pulse penetration will vary with canopy structural characteristics and ALS device configuration. Interpolating the point-sample ALS canopy measurements into a grid-based Digital Canopy Height Model propagated the observed errors, resulting in a negative bias of 1.02 m for shrub canopies and 2.12 m for tree canopies. Here the sampling density in relation to canopy surface roughness was important.},
}
-
P. Gong,
R. Pu,
G. S. Biging,
and M. R. Larrieu.
Estimation of forest leaf area index using vegetation indices derived from Hyperion hyperspectral data.
Geoscience and Remote Sensing, IEEE Transactions on,
41(6):1355-1362,
2003.
Note: Note: Issue: 6.
@article{RefWorks:832,
author={P. Gong and R. Pu and G. S. Biging and M. R. Larrieu},
year={2003},
title={Estimation of forest leaf area index using vegetation indices derived from Hyperion hyperspectral data},
journal={Geoscience and Remote Sensing, IEEE Transactions on},
volume={41},
number={6},
pages={1355-1362},
note={note: Issue: 6}
}
-
R. A. Haugerud,
D. J. Harding,
S. Y. Johnson,
J. L. Harless,
C. S. Weaver,
and B. L. Sherrod.
High-Resolution Lidar Topography of the Puget Lowland, Washington - A Bonanza for Earth Science.
GSA Today, Geological Society of America,
13(6):4-10,
2003.
@article{RefWorks:809,
author={R. A. Haugerud and D. J. Harding and S. Y. Johnson and J. L. Harless and C. S. Weaver and B. L. Sherrod},
year={2003},
title={High-Resolution Lidar Topography of the Puget Lowland, Washington - A Bonanza for Earth Science},
journal={GSA Today, Geological Society of America},
volume={13},
number={6},
pages={4-10}
}
-
R.A. Hill,
S.A. Hinsley,
D.L.A Gaveau,
and P.E. Bellamy.
Predicting habitat quality for Great Tits (Parus major) with airborne laser scanning data.
ijrs,
24:in press.,
2003.
Abstract: |
Habitat quality is a fundamental concept in ecology that is difficult to quantify objectively. In avian ecology, habitat quality is often inferred from demographic rates (Riddington and Gosler 1995), patterns of territory occupancy and stability (Matthysen 1990), or measurements of resource availability (Seki and Takano 1998). Vegetation structure is an important component of bird habitat quality (Fuller and Henderson 1992, Beier and Drennan 1997). For woodland birds, mapping the three-dimensional complexity of their habitat by field survey can be a time-consuming and difficult task. Airborne Laser Scanning (ALS) is a remote sensing technique, operating on a principle of Light Detection And Ranging (LiDAR) that supplies fine-grained information on vegetation structure at a woodland scale (Næsset 2002). The cover image shows a predictive map of reproductive performance in Great Tits (Parus major) based on a woodland canopy height model derived from ALS data. Since Great Tits feed their young on tree-dwelling lepidopteran larvae, canopy structure influences habitat quality via effects on both food abundance and its availability to the birds. Such remote quantification of habitat quality could greatly enhance our ability to predict impacts of changing environmental pressures on biodiversity. |
@Article{,
author = {R.A. Hill and S.A. Hinsley and D.L.A Gaveau and P.E. Bellamy},
title = { Predicting habitat quality for Great Tits (Parus major) with airborne laser scanning data},
journal = ijrs,
year = {2003},
volume = {24},
pages = {in press.},
number = {},
url = {},
keyword = {},
abstract = {Habitat quality is a fundamental concept in ecology that is difficult to quantify objectively. In avian ecology, habitat quality is often inferred from demographic rates (Riddington and Gosler 1995), patterns of territory occupancy and stability (Matthysen 1990), or measurements of resource availability (Seki and Takano 1998). Vegetation structure is an important component of bird habitat quality (Fuller and Henderson 1992, Beier and Drennan 1997). For woodland birds, mapping the three-dimensional complexity of their habitat by field survey can be a time-consuming and difficult task. Airborne Laser Scanning (ALS) is a remote sensing technique, operating on a principle of Light Detection And Ranging (LiDAR) that supplies fine-grained information on vegetation structure at a woodland scale (Næsset 2002). The cover image shows a predictive map of reproductive performance in Great Tits (Parus major) based on a woodland canopy height model derived from ALS data. Since Great Tits feed their young on tree-dwelling lepidopteran larvae, canopy structure influences habitat quality via effects on both food abundance and its availability to the birds. Such remote quantification of habitat quality could greatly enhance our ability to predict impacts of changing environmental pressures on biodiversity.},
}
-
J. R. Kupfer and J. A. Runkle.
Edge-mediated effects on stand dynamic processes in forest interiors: a coupled field and simulation approach.
Oikos,
101(1):135-146,
2003.
@article{RefWorks:816,
author={J. R. Kupfer and J. A. Runkle},
year={2003},
title={Edge-mediated effects on stand dynamic processes in forest interiors: a coupled field and simulation approach},
journal={Oikos},
volume={101},
number={1},
pages={135-146}
}
-
J.L. Lovell,
D.L.B. Jupp,
D.S. Culvenor,
and N.C. Coops.
Using airborne and ground-based ranging lidar to measure canopy structure in Australian forests.
cjrs,
29(5):607-622,
2003.
Abstract: |
Airborne and ground-based lidars are useful tools to probe the structure of forest canopies. Such information is not readily available from other remote sensing methods but is essential for modern forest inventory in which growth models and ecological assessment are becoming increasingly important. This study was undertaken to investigate the capacity of current airborne and ground-based ranging systems to provide data from which useful forest inventory parameters can be derived. Additional data collected included standard forest inventory, hemispherical photography, and optical point-quadrat sampling. Four contrasting study sites were established within an existing study area in the Bago and Maragle State Forests, New South Wales, Australia. A simple and standard set of models was fitted to the data to establish consistency between methods and current practice. Methods to reduce the bias induced by interaction of the size of the airborne laser scanner (ALS) footprint and thresholding used in ranging systems are demonstrated by the use of first and last returns and the intensity of the returns. A measure analogous to predominant height was calculated from an average of a number of the highest ALS returns within an area. This estimate agreed with field measured predominant heights within the uncertainty of the measurements. Data from a ground-based scanning rangefinder system were used to model leaf area index (LAI). These LAI estimates coincided with those from hemispherical canopy photographs. The validation work presented in this paper justifies further development of the instrumentation and analyses to combine results from multi-angular systems with data from airborne systems to alleviate some of the problems associated with the vertical view. Current laser ranging systems can be used to derive canopy structural parameters such as height, cover, and foliage profile provided information based on multiple returns or the intensity of returns is used to minimize the bias induced by the size of the footprint and the detection threshold. |
@Article{lovell03,
author = {J.L. Lovell and D.L.B. Jupp and D.S. Culvenor and N.C. Coops},
title = {Using airborne and ground-based ranging lidar to measure canopy structure in Australian forests },
journal = cjrs,
year = {2003},
volume = {29},
pages = {607-622},
number = {5},
url = {},
keyword = {},
abstract = {Airborne and ground-based lidars are useful tools to probe the structure of forest canopies. Such information is not readily available from other remote sensing methods but is essential for modern forest inventory in which growth models and ecological assessment are becoming increasingly important. This study was undertaken to investigate the capacity of current airborne and ground-based ranging systems to provide data from which useful forest inventory parameters can be derived. Additional data collected included standard forest inventory, hemispherical photography, and optical point-quadrat sampling. Four contrasting study sites were established within an existing study area in the Bago and Maragle State Forests, New South Wales, Australia. A simple and standard set of models was fitted to the data to establish consistency between methods and current practice. Methods to reduce the bias induced by interaction of the size of the airborne laser scanner (ALS) footprint and thresholding used in ranging systems are demonstrated by the use of first and last returns and the intensity of the returns. A measure analogous to predominant height was calculated from an average of a number of the highest ALS returns within an area. This estimate agreed with field measured predominant heights within the uncertainty of the measurements. Data from a ground-based scanning rangefinder system were used to model leaf area index (LAI). These LAI estimates coincided with those from hemispherical canopy photographs. The validation work presented in this paper justifies further development of the instrumentation and analyses to combine results from multi-angular systems with data from airborne systems to alleviate some of the problems associated with the vertical view. Current laser ranging systems can be used to derive canopy structural parameters such as height, cover, and foliage profile provided information based on multiple returns or the intensity of returns is used to minimize the bias induced by the size of the footprint and the detection threshold.},
}
-
R. Pike.
Forest Hydrologic Cycle Basics.
Streamline Watershed Management Bulletin,
7(1),
2003.
@article{RefWorks:871,
author={R. Pike},
year={2003},
title={Forest Hydrologic Cycle Basics},
journal={Streamline Watershed Management Bulletin},
volume={7},
number={1}
}
-
D. A. Roberts,
P. E. Dennison,
M. E. Gardner,
Y. Hetzel,
S. L. Ustin,
and C. T. Lee.
Evaluation of the potential of Hyperion for fire danger assessment by comparison to the Airborne Visible/Infrared Imaging Spectrometer.
Geoscience and Remote Sensing, IEEE Transactions on,
41:1297-1310,
2003.
Note: Note: Issue: 6.
@article{RefWorks:833,
author={D. A. Roberts and P. E. Dennison and M. E. Gardner and Y. Hetzel and S. L. Ustin and C. T. Lee},
year={2003},
title={Evaluation of the potential of Hyperion for fire danger assessment by comparison to the Airborne Visible/Infrared Imaging Spectrometer},
journal={Geoscience and Remote Sensing, IEEE Transactions on},
volume={41},
pages={1297-1310},
note={note: Issue: 6}
}
-
B. Tustison,
E. Foufoula-Georgiou,
and D. Harris.
Scale-recursive estimation for multisensor Quantitative Precipitation Forecast verification: A preliminary assessment.
Journal of Geophysical Research,
108(D8,8377),
2003.
@article{RefWorks:844,
author={B. Tustison and E. Foufoula-Georgiou and D. Harris},
year={2003},
title={Scale-recursive estimation for multisensor Quantitative Precipitation Forecast verification: A preliminary assessment},
journal={Journal of Geophysical Research},
volume={108},
number={D8,8377}
}
-
K. Zhang,
S. Chen,
D. Whitman,
J. Yan,
and C. Zhang.
A progressive morphological filter for removing nonground measurements from airborne LIDAR data.
IEEE Trans. Geosci. and Remote Sensing,
41(4),
2003.
@article{RefWorks:850,
author={K. Zhang and S. Chen and D. Whitman and J. Yan and C. Zhang},
year={2003},
title={A progressive morphological filter for removing nonground measurements from airborne LIDAR data},
journal={IEEE Trans. Geosci. and Remote Sensing},
volume={41},
number={4}
}