PROPRIETARY INFORMATION, EARTHDATA INTERNATIONAL UNAUTHORIZED DUPLICATION OR USE NOT PERMITTED WITHOUT PRIOR WRITTEN CONSENT

NC 2004 Lidar Workshop

Presentation:Generating Contours From

Lidar Data

Prepared by: Tonda Shelton & Bob Ryan

EarthData International

Methods for Generating Contours

• Bare earth points only

• Bare earth “filtered” points

• Filtered points with “draped” breaklines

• Filtered points with stereo compiled 3D breaklines

Bare Earth Only

ContoursGenerated

FromBare Earth

Only

Filtered Bare Earth• Proprietary Program: “LidTinFilter”

• Input: bare earth points

• Define contour interval

• Performs a distance and slope analysis to determine point thinning required

• Output: filtered points

ContoursGenerated

FromFiltered Pts

Only

Bare Earth Points

Filtered Points

ContoursGenerated

FromFiltered Pts

and “Draped”Breaklines

Contoursgenerated

from:Filtered Pts

and Compiled

3D Breaklines