Lab 9 - Corridor Analysis & Feature Extraction

GOAL AND BACKGROUND

The goal of this lab was to learn to project and navigate corridor LiDAR data. Feature extraction would also be explored.


METHODS

First, data's metadata was used to determine the projection of the data. The LAS tools in ArcMap were then used to define the projection for the data. The projected data was then opened in LP360, and some measurements were taken such as road widths and locations of power lines that were at risk for vegetation encroachment.

Next, building extraction was explored. Lake County data, classified in previous labs, was used for this. First, building footprints were extracted. Two shapefiles were created from this. One was a perfect outline of building points. The other was outlines with straight lines, which removed the noisy appearance of the footprints by making them more square. Lastly, the buildings heights were analyzed to determine qualification for FEMA's LOMA applications.

RESULTS

Shown below are two instances of vegetation encroachment on power lines found in the corridor data.

Shown below is an example of the difference between the non-squared footprints and the squared footprints, respectively. Notice the jagged lines in the non-squared footprints compared to the straight lines in the squared footprints.

Shown below is a map created of Lake County of buildings in the region that qualify for FEMA's LOMA applications. FEMA recently changed the cutoff from 810 ft ASL to 800 ft ASL. The map shows the buildings that the change affects.

SOURCES

Terrestrial LAS for Algoma, WI, project boundary KMZ, and metadata are from Ayres Associates.