For the InstructorThis material supports the Analyzing High Resolution Topography with TLS and SfM GETSI Module. If you would like your students to have access to this material, we suggest you either point them at the Student Version which omits the framing pages with information designed for faculty (and this box). Or you can download these pages in several formats that you can include in your course website or local Learning Managment System. Learn more about using, modifying, and sharing GETSI teaching materials.
- Design and conduct a complex TLS and/or SfM survey to address a geologic research question.
- Articulate the societal impetus for answering a given research question.
- Justify why TLS and/or SfM is the appropriate method in some circumstances.
Unit 1-TLS (Terrestrial Laser Scanning): Introduction to TLS
In this introductory module, you will learn the basics of designing and conducting a TLS survey. Laser scanners emit short pulses of light and detect the returned signal as the laser light bounces off the target object. The scanner calculates the distance to the target from the time delay of the returned signal. TLS requires a range of equipment, careful planning, and many hours of scanning in order to complete a successful survey, but it yields a high resolution topographic model valuable for addressing a range of geologic research questions. Unit 1-TLS may be used alone or concurrently with Unit 1-SfM.
- TLS Field Methods Manual (Acrobat (PDF) 24.7MB Nov1 16)
- TLS Data Processing and Exploration Manual (Acrobat (PDF) 1.6MB Sep22 16)
- Unit 1-TLS Student Exercise (Acrobat (PDF) 916kB Oct20 16)
Unit 1-SfM (Structure from Motion): Introduction to SfM
This is another introductory unit in which you learn how to design and conduct a Structure from Motion (SfM) photogrammetry survey. SfM method involves taking overlapping photographs of the same area or object. The processing software then creates a 3D model from changing position of the same points. SfM requires less expensive equipment and less field time but more processing time than TLS. In low-vegetation field areas, it can yield a similarly valuable high resolution topographic model applicable to a variety of geologic research questions. Unit 1-SfM may be used alone or concurrently with Unit 1-TLS.
- SfM Field Methods Manual for Students (Acrobat (PDF) 1MB Jun28 23)
- SfM Data Processing and Exploration Manual (Agisoft Metashape software) PDF (Acrobat (PDF) 8.4MB Nov16 19)
- Unit 1-SfM Student Exercise (Acrobat (PDF) 861kB May11 17)
Unit 2: Geodetic Survey of a Stratigraphic Section
Geodetic surveying techniques have many applications in sedimentology research, including lithological identification and analysis, sediment surface topography, and sequence stratigraphy. In this unit, you will design a survey of a sedimentary geologic outcrop to conduct a sequence stratigraphy analysis. The goal is to calculate deposition duration and sedimentation rate based on thicknesses extracted from the data. You will then tie these analyses back to societally important issues such as climatic change and energy extraction.
- Unit 2 Student Exercise - Stratigraphic Section Survey (Acrobat (PDF) 981kB Jul22 16)
Unit 3: Geodetic Survey of a Fault Scarp
Fault scarps are the topographic evidence of earthquakes large and shallow enough to break the ground surface. They are evidence of Quaternary fault activity. In this unit, you will design a survey of a fault scarp. The goal is to create a brief report summarizing the methods used and Quaternary history of displacements on the fault and thus important information about its potential earthquake hazard.
- Unit 3 Student Exercise - Fault Scarp Survey (Acrobat (PDF) 2.8MB Oct20 16)
- Unit 3 Student Exercise - Part B (Acrobat (PDF) 184kB Jul22 16)
This unit also includes an additional optional exercise in data processing (Unit 3.5), that your instructor may or may not include. If you do the data processing, you will learn to transform a point cloud into a digital elevation model (DEM) - also known as "high resolution topography". You will then be able to extract profiles of the scarp using ArcGIS and import these profiles into MATLAB to conduct hillslope diffusion analysis.
- Unit 3.5 Student Exercise - Optional hillslope diffusion with Matlab (Acrobat (PDF) 1.8MB Oct20 16)
Unit 4: Geodetic Survey for Geomorphic Change Detection
One major application of geodetic surveying techniques in geoscience research is quantifying change in geomorphological settings. This is done by finding the difference between repeat surveys of the same area. This application is used for analysis of river systems, forest fire effects, landslides, or any other erosional features. In this unit you will learn to clean up the data, remove vegetation, transform the point cloud to a DEM, and then compare that DEM to a previously collected data set to quantify change.
- Unit 4 Student Exercise - Geomorphic Change Detection (Acrobat (PDF) 752kB Oct20 16)
Unit 5: Analyzing High Resolution Topography Summative Assessment
Unit 5 is a final exercise and serves as your summative assessment for the module. In it you will demonstrate your skills in survey design, survey execution, and simple data exploration and analysis.
- Unit 5 Student Exercise - Module Summative Assessment (Acrobat (PDF) 970kB Jul22 16)
Prepared data sets
Some courses will not be collecting data in the field and will instead be using previously collected TLS and SfM data sets. Your instructor will tell you if you should work with any of these data sets.
- El Mayor Cucapah fault scarp - simple photo set (SfM) (Zip Archive 66.9MB Jun30 23), near Mexicali, Mexico
- Milligan Canyon sequence stratigraphy data (SfM) (Zip Archive 1433.4MB Jul3 23), Three Forks, Montana
- Dixon Canyon sequence stratigraphy data (SfM) (Zip Archive 221.8MB Jul3 23), Fork Collins, Colorado
- Fault scarp
- Landers fault scarp data (SfM) (Zip Archive 1238.5MB Jul3 23), Landers, California
- Change detection
- Aeolian dunes change detection (airborne lidar) (Zip Archive 18.5MB Jul3 23), White Sands National Monument, New Mexico
- Anthropogenic and geomorphic change detection at a beach (airborne & TLS) (Zip Archive 19.5MB Nov3 16), Muskegon State Park, Michigan
- Other applications
- Wasatch Fault Paleoseismic Trench (SfM), Utah - note: data set is fairly large so it is downloadable from Dropbox here