GIS/MEA 584:
Mapping and Analysis Using UAS

Topic 4: GIS Analytics

A. Analysis of UAS data processing results

Outline:

• Compare survey data and errors from different flights
• Recognize differences in geoprocessing products generated by different softwares
• Understand significance of using GCPs in the processing and their impact on the final products
• Recognize what processing steps need to be modified in order to improve particular errors
• Understand what causes the 'Bowl effect' and know the solutions to fix it
• Execute distance, area and volume measurements

Lecture:

• Lecture Slides

• Bowl effect explained: Mitigating systematic error in topographic models derived from UAVand ground-based image networks
• Image residuals, camera calibration and impact of GCPs: Evaluation of structure from motion for soil microtopography measurement
• Alternative to GCPs - RTK/PPK equipped UAS: Do RTK/PPK drones give you better results than using GCPs?

Assignment 4A.

• Execute measurements in Agisoft Metashape
• Analyze differences in DSMs generated using different techniques or acquired at different times. Distiguish between errors, artifacts and real change in vegetation and/or bare ground surface.

Homework:

B. Point cloud data analysis

Outline:

• characteristics of UAS SfM and lidar-based point cloud data
• point cloud data representation and formats
• point cloud data processing, visualization, and analysis
• bare earth point extraction
• working with classified point clouds
• computing DEM and topographic analysis
• voxel-based analysis and vertical profiles

Lecture:

• Lecture slides
• Lecture recordings: Properties, Processing, and DEMs and voxel models

• Processing point clouds in GRASS GIS, workshop presented at FOSS4G conference in Boston in 2017 (start with the section "Binning the point cloud").
• LAS specification v1.4-R13, July 2013
• Lidar and INS

Assignment 4B

• Processing lidar and UAS SfM point clouds

Homework: