Contour Mapping from LiDAR Presented by: Dave Bullington Surdex Corporation St. Louis, MO

Surdex Corporation ■Surdex headquartered in St. Louis, MO area ■Over a half-century of photogrammetric mapping ~100 employees 8 aircraft – 4 Cessna 441 (Conquest) Turbine Aircraft 3 Intergraph Digital Mapping Cameras (DMC) 1 Microsoft Vexcel UltraCam XP Wide Angle 5 film cameras Leica ALS50 II LiDAR Sensor ■Very progressive R&D Large amount of proprietary algorithms and software Focus on cost-efficiency and performance

State of the Art Equipment

Surdex Aircraft

Surdex’s Client Base ■ Federal Government USACE, USDA, DNR, USGS, FEMA, EPA ■ State Government Statewide Programs, DOT’s, SEMA ■ Local Government County, City, RPC’s ■ Private Sector Civil Engineering, Real Estate, Development, Mining, Oil & Gas

Deliverables ■Digital Orthophotography (4 Band) ■LiDAR ■Planimetric Mapping ■Topographic Mapping ■Ground Control Survey ■GIS Services

LiDAR Processing GPS/IMU Processing IMU Data Reduction GC Check Position Attitude GPS LASER Measurements (Range, Angle, Time) Classification X,Y,Z Point Cloud Stereo QC / Edit Classified Points (Bare-earth, veg/building) Stereo Images Data Thinning TIN Break- lines DTM Surface AUTOMATIC MANUAL 2D Edit TIN LASER Intensity, RGB Ortho Photos

LiDAR Data ■First, middle, last return Position (X,Y) Elevation (Z) Intensity ■Products Intensity Image Digital Surface Model Digital Terrain Model Classification Contours

First Returns Second Returns Third Returns Last Returns All Returns

Elevation Cross Section

Ground Cross Section

First Return DEM Bare Earth DEM Calculations 1.Identify man made structures Determine ground elevation at edges 2. Identify vegetated areas Search for ground points within area 3. Identify open areas 4. Interpolate between available points 5. Filtering and clean- up

Bare Earth DEM Automatically extracted Bare Earth DEM Ground surface with vegetation and man-made structures removed Critical for terrain and hydrology modeling

Bare Earth DEM with 1 meter contours

Raw vs. Edited LiDAR Contours Contours from raw LiDAR data Contours from raw LiDAR data with photogrammetric edits

Types of LiDAR DTM & Contours ■Level I Classified to Bare earth only, automated ■Level II Classified to bare earth Automated, minimal cartographic edits ■Level III Classified to bare earth Break-lines added to hydrology Similar cartographic edits of Level II

Types of LiDAR DTM & Contours ■Level IV Level III plus: Stereo Compiled Breaklines Planimetric Features (optional)

Level 1-2 surface

Level 1

Level 1 Surface and Contours

Level 2 Contours

Level 2 Surface and Contours

Level 3 Breaklines

Level 3 surface

Level 1-2 SurfaceLevel 3 Surface

Level 3 Surface and Contours

Level 3 Contours

Level 3 Contours with Breaklines

Level 3

Level 4 Photogrammetric Enhanced