GIS/MEA 584:
Mapping and Analysis Using UAS



Topic 2: Structure from Motion

A. From images to 3D models: Photogrammetry and Structure from Motion concepts

Outline:

  • principles of photogrammetry
  • UAS low range flight and consumer camera image acquisition
  • lateral and forward overlap, stereoscopic coverage
  • principles of Structure from Motion
  • 3D reconstruction from multiple overlapping imagery

Lecture:

Supplemental materials:

Assignment 2A

Perform an experiment to investigate impact of the number and orientation of photos, light, as well as shape and features of a photographed object on its 3D reconstruction from multiple overlapping imagery.

Homework:

Prepare short report on your 3D modeling experiment.

3D models from previous courses are available on OsgeoLab Skechfab account. If you would like your model to be added to the collectionl please indicate at the end of your report
"I agree for my 3D model to be uploaded to the OsgeoLab Skechfab collection and I want(/don't want) my name to be listed as an author in the model description"
and submit on through moodle your 3D model (preferably in the .obj format with accompaning .mtl and .jpg files, or check other formats supported by Sketchfab)

B. Imagery processing and structure from motion (SfM)

Outline:

  • aerial imagery distortions
  • orthorectification process
  • interior and exterior orientation
  • Bundle Block Adjustment
  • Ground control points
  • image mosaic and point cloud results
  • structure from motion

Lecture:

Supplemental materials:

  • Y. Furukawa and C. Hernández . Multi-View Stereo: A Tutorial. Foundations and TrendsR in Computer Graphics and Vision, vol. 9, no. 1-2, pp. 1–148, 2013.

Assignment 2B:

Homework:

Prepare report on generating orthomosaic and Digital Surface Model using images taken by the UAS Trimble UX5 Rover and performing the processing in Agisoft Metashape. Explain the report generated by Agisoft including the data accuracy.