DOI: 10.1016/j.jag.2014.02.009
Scopus记录号: 2-s2.0-84904480283
论文题名: Accuracy of vegetation height and terrain elevation derivedfrom ICESat/GLAS in forested areas
作者: Enßle F ; , Heinzel J ; , Koch B
刊名: International Journal of Applied Earth Observation and Geoinformation
ISSN: 15698432
出版年: 2014
卷: 31, 期: 1 起始页码: 37
结束页码: 44
语种: 英语
英文关键词: ALS
; Canopy height
; Elevation
; GLAS
; ICESat
; Lidar
Scopus关键词: airborne sensor
; altimetry
; canopy
; elevation
; Gaussian method
; height
; ICESat
; land surface
; lidar
; regression analysis
; slope angle
; terrain
; topography
; vegetation
; waveform analysis
英文摘要: This paper focuses on accuracy assessment of canopy top elevation, ground elevation and vegetationheight (VH) derived from space borne full-waveform LiDAR (Light Detection And Ranging) data acrossforested areas. Computed height metrics from LiDAR data which were acquired by the GLAS sensoraboard the ICESat (Ice Cloud and land Elevation Satellite) are compared against airborne laser scanning(ALS) based digital elevation models. Due to the dynamic topography of the sites under investigation,a wide range of slope angles could be investigated. ICESat's raw waveform data (GLA01) and the landsurface altimetry data (GLA14) products are used to determine height metrics with different methods.GLA14 based elevation and vegetation heights are computed from range offset information. Values areprovided for signal begin, signal end, land range and up to six Gaussian peaks for each received waveform.GLA01 based terrain heights are computed by locally weighted polynomial regression and peak detectionon the received waveform itself. A range of different smoothing spans and noise threshold values onthe original waveform, which is represented by 544 single values (bins), were tested. A new methodbased on the unsmoothed waveform was developed for the detection of the signal begin. By detectingthe location above the noise threshold, where the signal rises at least for 5 bins (75 cm), achieved moreprecise results, than the given signal begin in the GLA14 product. For ground peak detection by smoothingof the waveform it was found that noise thresholds of 4 and 4.5 times the standard deviation plus themean noise level give the best performance. For VH computation in areas of up to 10°terrain slope, asmoothing span of 10 bins achieved r2= 0.58, whereas the GLA14 based method achieved r2of 0.75 in flatterrain (0-5°). For these flat areas, best results in VH computation (r2= 0.91) were achieved by using thenew method for canopy top detection and the GLA14 based ground elevations. Determination of terrainelevations was observed to be best by computation with GLA14 based parameters. The stronger of secondlast two peaks was found to be closest to the ground level elevation. © 2014 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/79769
Appears in Collections: 气候变化事实与影响
There are no files associated with this item.
作者单位: Remote Sensing and Landscape Information Systems, University of Freiburg, Tennenbacherstraße, 4, D-79106 Freiburg, Germany; European Commission - Joint Research Centre, Institute forthe Protection and Security of the Citizen, Global Security and Crisis Management, Ispra, Italy
Recommended Citation:
Enßle F,, Heinzel J,, Koch B. Accuracy of vegetation height and terrain elevation derivedfrom ICESat/GLAS in forested areas[J]. International Journal of Applied Earth Observation and Geoinformation,2014-01-01,31(1)