3001 lidar services vgin presentation – december 2007
TRANSCRIPT
3001 LiDAR Services
VGIN Presentation – December 2007
3001 LiDAR History
• Co-developed one of the first commercial topographic LiDAR sensors – deployed in 1997
• Developed and continually upgraded proprietary LiDAR processing software, ELVIS®, to fill industry void
• Helped pioneer the application of LiDAR for floodplain mapping with work in the Everglades and in Southern Louisiana
• Helped pioneer the use of LiDAR for large scale topographic mapping programs on Louisiana’s Statewide LiDAR program
3001 LiDAR Sensors
• We offer the two most advanced LiDAR sensors on the market– Optech ALTM Gemini with Multipulse
• 167 kHz pulse rate– Leica ALS50 Phase II with Multipulse
• 150 kHz pulse rate
• Both ideal for large scale mapping
• Advances save the customer money– Higher pulse rate and Multipulse technology allows
higher collection altitude and less flight lines, equaling lower cost while still meeting FEMA standards and customer specifications
3001 Resources
• 3 LiDAR Sensors– Optech ALTM Gemini with Multipulse– Leica ALS50 Phase II with Multipulse– Leica ALS40
• 5 Digital Cameras– 2 Z/I DMCs (frame)– 3 Leica ADS40 Phase IIs (push-broom)
• 9 Aircraft– 7 Twin-Engine Cessnas– 2 LearJets
3001 LiDAR Experience
• 10+ years of LiDAR project and R&D experience
• Nationwide projects– From Alaska to Florida
• Customers include states, counties, cities, U.S. Army Corps of Engineers, U.S. Navy, FEMA, and the National Geospatial-Intelligence Agency
• We estimate our LiDAR past performance to encompass more than 150,000 square miles
• Recently awarded 5-year contract by the Federal government to provide worldwide operations and maintenance of the JALBTCX CHARTS system – bathymetric LiDAR mapping and hyperspectral imaging
Processing – Where It Counts
• There is typically little variation in raw LiDAR datasets given vendors follow standard collection protocol
• The real “finesse” with LiDAR is in processing– Boresighting– Filtering– Manual editing
• 3001 developed ELVIS® to give us abilities not available in COTS software
ELVIS®
• The result: the most robust LiDAR editing environment in the industry that allows the analyst to customize every aspect of the processing– Your product is not the result of a standard filter/edit setting; it
is a unique, customized throughput that provides an elevation model that truly represents your terrain
Meeting Federal Standards
• FEMA’s Guidelines and Specifications for Flood Hazard Mapping Partners is accepted by most as the national standard for elevation data
• Our data are certified to meet FEMA vertical accuracy specifications for 2’ contours (RMSEz = 18.5 cm / Accuracyz = 36.3 cm) at a nominal post spacing of 3 m
• Accuracy has two definitions with LiDAR– Accuracy identifying the elevation (Z) at a particular XY position– Accuracy depicting the true topography of the Earth
Two Definitions of Accuracy
• Accuracy identifying the elevation (Z) at a particular XY position (Vertical Accuracy)– Predominantly influenced by post-processing, editing, and ground
control surveying• Post-processing/boresighting ensures trajectory consistency across the
dataset• Accurate filtering and editing ensures only the points that reflect off the
ground are identified as such and remain in the bare-earth dataset
– A well planned and executed ground control survey can mean the difference between certifiable data and just a pretty picture
• 2 GPS base stations for coincident positioning and triangulation – operated during airborne data collection, not to exceed 35 km from aircraft at all times
• Land cover checkpoint surveys to verify positioning in the predominant land cover of the project area(s) – conducted post-airborne operations, minimum of 5 land cover classes, minimum 40 points per class
Two Definitions of Accuracy
• Accuracy depicting the true topography of the Earth (Model Accuracy)– Largely dependent on the data collection methodology, point
density, post-processing, and quality of the data filtering and editing• Successful flight planning ensures consistent point spacing across
the dataset and quality data with which to work• Higher point density means more detail – but is it necessary?• Diligent post-processing ensures consistency across the dataset• Accurate editing ensures ground points remain in the bare-earth
dataset
• Your dataset should meet both definitions for accuracy
Example Flight
Project Flight Path
BoresightFlight Path
GPS Base Station
Accuracy and the Sensor
• What is contingent upon the LiDAR sensor?– Flight/data collection parameters
• The sensor (and aircraft) dictates your operating altitude, pulse rate, flight line spacing, air speed, etc.
Data Density
• 1 m LiDAR product provides 25x more surface detail than a 5 m LiDAR product but also requires much more storage
• Next slide illustrates the difference in detail between 5 m and 1 m LiDAR models
5 m Bare-Earth LiDAR Model5 m Bare-Earth LiDAR Terrain Model1 m Bare-Earth LiDAR Terrain Model
3001 Data
• LiDAR products include– Elevation models (terrain and surface) ranging from 5 m to sub-meter– Breaklines– 2’ contours
• We certify our LiDAR data to meet FEMA 2’ contour specifications
• 100% of our data is better than 15 cm RMSEz
– Well exceeding FEMA standard (18.5 cm RMSEz)– 70% of our data is better than 9 cm RMSEz
• 2D and 3D breaklines developed– 2D collection and draping, and
• Most hydrographic features can be enforced in this manner– 3D LiDAR-grammetry where needed
• Best used for bridge aprons, edge of pavement, and building– Breaklines collected without supporting imagery are limited by LiDAR post
spacing and horizontal accuracy (+/- 0.5 m)
Quality Management is Key
LiDAR in Real Life
• Redefining flood plains
Q3 Flood Plain
LIDAR Flood Plain Additional homes in the flood plain
LiDAR in Real Life
• Emergency response routing and evacuation: According to State officials, 10 lives were saved in Louisiana by having 3001 LiDAR maps during the Katrina response
LiDAR in Real Life
• Forest metrics
LiDAR in Real Life
• River morphology
Contact Information
Tom Bertke
Area Director
Fairfax, VA
Office: 703.385.3001, ext. 1902
Mobile: 703.850.8032
Carter Christopher
Area Director
Fairfax, VA
Office: 703.385.3001, ext. 0199
Mobile: 504.810.4748