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Interoperable Data Systems for Satellite, Airborne and Terrestrial LiDAR Data. C. Meertens and J. McWhirter, UNAVCO S-J. S.Khalsa and T. Haran, NSIDC/CU C. Baru and C. Crosby, SDSC/UCSD D. Harding and B. Blair, NASA/GSFC and M. Hofton, U. Maryland.
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Interoperable Data Systems for Satellite, Airborne and Terrestrial LiDAR Data C. Meertens and J. McWhirter, UNAVCO S-J. S.Khalsa and T. Haran, NSIDC/CU C. Baru and C. Crosby, SDSC/UCSD D. Harding and B. Blair, NASA/GSFC and M. Hofton, U. Maryland ACCESS: Advancing Collaborative Connections for Earth System Science
LiDAR Data Platforms Distributed and Large Collections from a diverse set of LiDAR Platforms 5 million points/day 10 km altitude 10 m footprint ~500 thousand points/day 600 km altitude 70 m footprint High Altitude Airborne Laser Vegetation Imaging System ( LVIS) Satellite - Icesat 500 million-1 billion/day 0.5 km altitude 20 cm footprint 100-500 million points/day tripod 1 cm footprint Low Altitude Airborne Laser Scanning Terrestrial LiDAR Scanning
NLAS System Overview Objective of NLAS Project (NASA Laser Access System) • Provide an integrated system (NLAS) for web services-based access to distributed NASA airborne (LVIS) and satellite (ICESAT/GLAS) LiDAR data archives using OpenTopography technologies. (Google NLAS Opentopography)
NLAS System Overview • OpenTopography Currently: • Provides users access to ten’s of billions of LiDAR point cloud measurements and in industry standard formats (e.g. ascii, LAS) • Provides on-demand processing services to enable generation of digital elevation models (DEMs), derivative products and visualizations. • NLAS will provide: • Web Services access to distributed archives using a downloadable data repository package (NLAS/RAMADDA) • Integrated access to NLAS data via OpenTopography • An extensible Java package for reading and writing various LiDAR formats • Add full waveform access and enhanced quality control (QC) metrics for ICESat/GLAS and LVIS USERS OpenTopography NLAS RAMADDA LVIS ICESat/GLAS
Open Topography • OpenTopography Search • Map Interface • Metadata about Dataset • Access to download and processing interface • See demo at OpenTopography Booth! OpenTopography is funded through the National Science Foundation
Open Topography – Data Access Data Downloading and Processing User specifies Download/Processing Parameters 1.) Select area from Map Interface 2.) Point Cloud - Select format (ASCII or LAS) 3.) DEM Generation -Select Gridding Method, parameters, and format
Open Topography - Results Page • OpenTopography • On-demand Processing Products: • Subset of point cloud data • Digital Elevation (DEM) Map • Visualization product and .kmz file if desired • DEM on browser embedded GoogleEarth LVIS example in Sierra Nevada
Open Topography - Other LiDAR Examples • Terrestrial Laser Scanning example • Subset area of interest • Download options include: ASCII Point Cloud, DEM, Hillshade & Slope Products, kmz, and image • ICESat/GLAS example • Subset area of interest (left) • Download ASCII Lat, Long, Elev (X,Y,Z) • Example of subsequent import into Excel and plot of shot number vrs elevation (right)
Interoperability with Data Repository Web Service Open Topography Visualization/Analysis Clients NLAS Interoperability HTML Interface NLAS Web Service NLAS/RAMADDA NLAS Web Service
NLAS Data Repository – LVIS Example NLAS/RAMADDA Capabilities and Data Queries Web services • Spatial queries • Spatial/temporal subset • Data Conversion • Product generation Open Topography Portal Metadata Database Responses and Data Metadata harvesting LiDAR Tools File store Ingest Other Clients LCE, LGE, LGW LVIS Data System LVIS Product Generation
NLAS/RAMADDA RAMADDA Overview • Data repository framework developed at Unidata/UCAR • Freely available Java based open source package • Extensible plugin architecture • Basic content management functionality NLAS/RAMADDA plugin to support LiDAR data services • LiDAR data ingest, metadata harvesting and publication • Services include: • Map overview, time series and waveform displays • Spatial subset, decimation • Conversion to multiple data format: original binary, LAS, ASCII CSV, … • Product generation - Image, hill shade image, KMZ
NLAS/LiDAR Tools NLAS/LiDAR Tools Stand-alone Extensible Java package for reading and writing various LiDAR formats • LAS • LVIS (including waveform) • ICESAT/GLAS products • Other Icebridge formats – ATM, MCORDS, PARIS • Terrestrial Laser Scanning formats – text, PTX • Transforms global XYZ to Lat, Long, Elevation • …
LiDAR Subset Form Data Access direct from NLAS/RAMADDA
LiDAR Waveform Data Full Waveform LiDAR Data Transmit Pulse Alternate Signal Start Outer Canopy Relief Canopy Inflection Standard Gaussian Fit Within Canopy Light Extinction Ground Relief Alternate Signal End 1064 nm laser pulse footprint ~ 70 m diameter spaced 175 m along profile Amplitude (volts)
NLAS/RAMADDA Waveform Display NLAS/RAMADDA Waveform Display
Status and Next Steps Accomplishments • LiDAR data repository framework • NLAS/RAMADDA Data Repository • LiDAR Data translation software tool • End-to-end proof of concept • LVIS, ICESat GLAS, TLS • New GLAS product • GLANL containing enhanced QC Some Next Steps • Define NLAS web service API • Data and metadata discovery • Data service access • Implement NLAS production servers for GLAS and LVIS data sets • Implement full wave form service into OpenTopography • Explore potential application of NLAS services to other data sets – ATM, TLS, etc. GSFC LVIS Antarctic Glacier Scan