Interoperable Data Systems for Satellite, Airborne and Terrestrial LiDAR Data

C. Meertens and J. McWhirter, UNAVCOS-J. S.Khalsa and T. Haran, NSIDC/CUC. 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

High Altitude AirborneLaser Vegetation Imaging System ( LVIS)

~500 thousand points/day600 km altitude70 m footprint

Terrestrial LiDAR Scanning

100-500 million points/daytripod1 cm footprint

Satellite - Icesat

Low Altitude Airborne Laser Scanning

500 million-1 billion/day0.5 km altitude20 cm footprint

LiDAR Data Platforms

5 million points/day10 km altitude10 m footprint

Distributed and Large Collections from a diverse set of LiDAR Platforms

NLAS System Overview

• 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)

Objective of NLAS Project(NASA Laser Access System)

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

OpenTopographyOpenTopography

LVIS

LVIS

ICESat/GLASICESat/GLAS

NLAS RAMADDANLAS RAMADDA

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

OpenTopographyOn-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

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)

Terrestrial Laser Scanning example• Subset area of interest• Download options include: ASCII Point Cloud, DEM, Hillshade & Slope Products, kmz, and image

NLAS Interoperability

NLAS/RAMADDA

Open Topography Visualization/Analysis Clients

NLAS Web Service

HTML Interface

NLAS Web Service

Interoperability with DataRepository Web Service

NLAS Data Repository – LVIS Example

NLAS/RAMADDA

Open Topography

Portal

Web services

•Spatial queries•Spatial/temporal subset•Data Conversion•Product generation

Ingest

MetadataDatabase

Other Clients

Capabilities and Data Queries

Responses and Data

Metadataharvesting

LVIS Data System

File store

LiDAR Tools

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

Transmit Pulse

Alternate Signal Start

Outer Canopy Relief

Canopy InflectionStandard Gaussian Fit

Within Canopy Light Extinction

Ground ReliefAlternate Signal End

Amplitude (volts)

1064 nm laser pulse footprint~ 70 m diameter spaced 175 m along profile

Full Waveform LiDAR Data

NLAS/RAMADDA Waveform Display

NLAS/RAMADDAWaveform 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 LVISAntarctic Glacier Scan