Coastal Lidar BreakdownConcerns, Trends & Data Availability
Eric Morris
Northwest GIS User’s ConferenceOctober 16, 2014
Active System•Uses laser ranges, scan angle & positional IMU data to produce x,y,z and intensity for corresponding ground returns
Basics of Light Detection and Ranging
• Accuracies dependent on calibration and GPS base station
• Post-processing is costly• Collected, stored in “point
clouds”• ≥400,000 pulses/sec• ~a million data points
every 2.5 seconds.
Basics of Light Detection and Ranging
A (Brief) History of Lidar
• 1960s – lunar laser ranging (to aid Apollo landing)• 1977 – NOAA/NASA AOL looked to the clouds• 1993 – GPS & IMU allowed accurate airborne use• 2003 – ASPRS LAS 1.0 format (open source)• 2010 – National Enhanced Elevation Assessment (NEEA)
• 2012 – U.S. Interagency Elevation Inventory• 2014 – 3DEP • ~2020 – GEDI – worldwide canopy at 1 m
Airborne Lidar Bathymetry (ALB)
• Applicable to oceans, rivers, lakes
• Tides
• Snell’s Law
• Water Clarity
• Eye safety
• Air Space
• Refraction
“Requires more everything”
Tampa Bay, FL
Kirk Waters, PhD, Applied Sciences, NOAA OCM
Amar Nayegandhi, Director of Remote Sensing, Dewberry
Chris Parrish, PhD, formerly of the NOAA NGS and NOAA CCOM-JHC, now at Oregon State Univ.’s School of
Civil and Construction Engineering
Special Thanks and Acknowledgements