Pelatihan : Techniques in Active Tectonic Study Juni 20-Juli 2, 2013 Instruktur: Prof. J Ramon Arrowsmith (JRA) Dari Arizona State University (ASU) - US Tempat Pelaksanaan: Ruang Pangea, Laboratorium Gempabumi (LabEarth) – Puslit Geoteknologi LIPI dan Kuliah lapangan akan dilakukan disekitar Sesar Lembang, Jawa Barat. * Lebih jelas baca TOR/KAK dan daftar acara

High resolution topography exercise and discussion

Airborne Laser Swath Mapping (ALSM) 1.Laser scanner 2.Inertial Measurement Unit (IMU) 3.GPS -Phillips, UNAVCO

R. Haugerud, U.S.G.S D. Harding, NASA Answer science question Gridded products Geodesy and signal processing Point Cloud x n, y n, z n, i n ALSM workflow: Survey->Process->Classify->Interpolate/Grid->Analyze

Ecology Applications: 3D vegetation information & interactions between vegetation and topography 3D vegetation structure: –estimation of stand height –total aboveground biomass –foliage biomass –basal area –tree density, –canopy base height –canopy bulk density Stoker et al., 2006

Comparisons of Techniques for measuring surfaces and detecting changes in surfaces* GPSInSARALSMTLS Sample Density 1 site/10 km 2 10,000 pixels/ km hits/ m hits/ m 2 Position Precision 1-20 mm2-3 m5-15 cm0.6-5 cm Change Detection 1 mm1-2 cm10 cm1 cm Scale Global100 km Km1 km * Ball park numbers for typical applications -Phillips, Meertens, and Jackson, UNAVCO

x,y,z + attributes Filtering algorithms allow classification by return type: –Ground, vegetation, building … LiDAR “point cloud”

Digital Elevation Models Digital representation of topography / terrain –“Raster” format – a grid of squares or “pixels” –Continuous surface where Z (elevation) is estimated on a regular X,Y grid –“2.5D” Grid resolution is defined by the size in the horizontal dimension of the pixel – 1 meter DEM has pixels 1 m x 1m assigned a single elevation value. Source:

1 meter grid LiDAR returns from EarthScope data collection Example from flat area with little or no vegetation so ground is sampled approx. 5+ times per square meter How do we best fit a continuous surface to these points? Ultimately wish to represent irregularly sampled data on a regularized grid. 1 meter

Facilitate community access to high-resolution, Earth science- oriented, topography data, and related tools and resources.

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