2025 NSF GAGE/SAGE Community Science Workshop

2025 NSF GAGE/SAGE Community Science Workshop:

Introduction to OpenTopography Tools for Calculating Change at the Earth’s Surface

Sunday, May 18th, 2025, 1 pm – 5 pm

Conference Information

Location: Nakomis B, Radisson Blu Mall of America, Bloomington, MN

Instructors: Cassandra Brigham, Arizona State University & Christopher Crosby, EarthScope Consortium

Course Description:

The growing availability of multi-temporal high resolution topography datasets from lidar and photogrammetry offer the opportunity to reveal surface change from a variety of tectonic, geomorphic, and anthropogenic processes including earthquakes, volcanic eruptions, river erosion, landslides, sand dune migration, and urban development. OpenTopography is an NSF supported initiative that strives to streamline hosting, discovery, processing, visualization, and analysis of topographic data.

This short course will provide an introduction to the OpenTopography platform for accessing and processing high-resolution topography, with a focus on tools for computing topographic change from multi-temporal data. After a brief refresher on lidar and structure from motion photogrammetry, we will explore OpenTopography’s on-demand tools for calculating vertical differences between overlapping datasets. We will also discuss how to interpret topographic change results using a new uncertainty analysis tool. Through hands-on exercises, attendees will learn to process multi-temporal datasets to quantify landscape change, and to correctly interpret differencing results. This workshop is ideal for students, educators, researchers, and professional geoscientists looking to gain practical experience in using freely available, high-resolution topographic data and OpenTopography’s streamlined processing capabilities.

Participant Guidelines & Pre-course Preparations:

We will run this short course with the OpenTopography web-based interface and the Google Colaboratory web-based interface. To prepare for the course please complete the following tasks in advance of the course:

    1. Ensure you have a Gmail account and at least 500 MB of Google Drive space
    2. Create an OpenTopography account (if you do not already have one) at https://opentopography.org
    3. Bring a laptop capable of connecting to the conference WiFi network, ideally with a webGL enabled browser like Chrome or Firefox
    4. (optional) bring personal datasets for differencing, to be used if time permits

Tentative Agenda:

    1:00 pm Welcome and course introduction. Around the room intros. (Brigham & Crosby)

    1:30 pm Lecture & activity: Introduction to OpenTopography and short tour of the OT website. Get differencing jobs running via the OT-browser. (Crosby)

    2:15 pm Break

    2:30 pm Lecture: Differencing and error analysis in OpenTopography (Brigham)

    3:30 pm Discussion: Review participants' differencing results (Brigham & Crosby)

    3:45 pm Activity: Colab differencing and error exercise. (Brigham)

    4:45 pm Discussion

    5:00 pm Short Course End

Course Resources:

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