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2024 Technical Short Course: GNSS Data Processing and Analysis with GAMIT/GLOBK and track

Date(s): July 22-26, 2024
Location: Virtual

The course is designed to benefit anyone (undergraduate and above) who intends to process GNSS data, manipulate GNSS products for their research or understand more about the specifics of any GNSS product which they may use. Participants should have a basic understanding of and experience with command-line interaction to install and run the software. The course will be taught by a combination of presentations on the concepts to understand and practice times during which participants are expected to work on processing their own data sets, with the instructors available for direct tuition.  Some demonstrations will be offered by the instructors based on needs. 

The workshop will be divided into three parts to accommodate differing levels of experience, and both static and kinematic applications. Monday’s lectures will be a review of GAMIT and GLOBK commands and file structures, and useful Unix command-line sequences not incorporated into scripts. Tuesday afternoon through Thursday will feature lectures on reference frame realization, error analysis, and efficient processing of both continuous and survey-mode observations. On all four days, there will be time allotted for one-on-one tutoring using participants’ own data sets, which we recommend participants either have already or search for data with which to practice during the course.Friday will focus on kinematic measurements and various examples of applications. Participants interested only in static measurements may wish to remain through Friday for one-on-one tutoring in a parallel session. Participants interested only in static measurements may wish to remain through Friday for one-on-one tutoring in a parallel session.

Time: Two daily 90-minute plenary sessions, as well as two 90-minute office hour sessions.
Primary Audience: Intermediate to advanced level users of the GNSS processing software suite
GAMIT/GLOBK and kinematic module track.
Secondary Audience: Beginning users and those who wish to learn about GNSS processing from
raw data to time series and velocities, and their basic analysis for geophysics.

Learning Objectives 

This course is intended for those who plan to process raw GNSS data, either for static or kinematic experiments, or for those who would like to understand more about the generation and characteristics of GNSS products. The course is intended to teach the use of the GAMIT/GLOBK software, not the use of GNSS for geophysics in general.

After participating in the course, attendees will gain confidence in their ability to construct files and directories to process GNSS data with GAMIT. 

After participating in the course, attendees will gain confidence in utilizing raw GNSS data to generate position and velocity estimates, involving different noise sources with GAMIT and GLOBK. 

After participating in the course, attendees will gain confidence in their ability to propagate data results as well as phase processing results from other software into GLOBK. 

After participating in the course, attendees will gain confidence in their ability to plot the resulting time series and velocities, and combine and manipulate time series and velocity files from other sources with utility programs and scripts.

Participant Commitment

Participants will be expected to have installed GAMIT/GLOBK and demonstrably run the “test_install” package before acceptance to this course (expected time burden: half a day) and will be expected to attend at least the first day (for all interests), the second and third days for geophysical time series and velocity generation and analysis, the fourth day for advanced concepts and the fifth day for use of track. Instructors will be available for any topic of discussion on all days.

Prerequisites, Computer and Data

  • GAGE raw/RINEX data archive and time series and velocity products. EarthScope Engagement resources  such as hosting webinar recordings.
  • Laptop capable of running Unix-like environment (e.g. Linux, macOS, Windows Subsystem for Linux). 
  • GAMIT/GLOBK license (see http://geoweb.mit.edu/gg/) and associated prerequisites (e.g.http://geoweb.mit.edu/gg/pre.php).
  • At least 4 Mbps for remote participation through video conferencing software for the duration of the Short Course. Similar speeds and duration are required for efficient downloading of data and products with which to process using the software.
  • Some knowledge of the use of GNSS positioning and velocities for geophysics is preferable.
  • Basic command line interaction and some knowledge of compiling Fortran/C programs.

Brief Agenda

July 22 – Fundamentals of GNSS for geodesy
– Basics of processing workflow for GAMIT/GLOBK
– Batch processing with sh_gamit
July 23 – Post-processing with GLOBK
– Generating time series with glred
– Generating velocity solutions with globk
July 24 – Reference frames
– Time series and error analysis
– Dealing with earthquakes and non-linear motions
July 25 – Vertical loading and atmospheric parameters
– Processing large continuous networks
July 26 – Introduction to and basics of processing with track
– Examples using track

Assessment

GAMIT/GLOBK and track have many uses and types of output, so participants will gain the most from the course by defining their own ultimate goals before attending. Each participant ideally is expected to come with their own goals, and data to process, so we will judge their progress against their own criteria. At minimum, this will include setting up a processing experiment, ingesting data into GAMIT and generating outputs which may be anything relevant to their geophysical analysis (e.g. atmospheric delay estimates, position time series, tectonic velocities, earthquake displacements, etc.) For those who attend without a specific project or goal in mind, we will assign a generic example data set for them to use with the software. We will also judge participants on their level of direct interaction with the instructors throughout the course.

Instructors

  • Mike Floyd, Massachusetts Institute of Technology
  • Thomas Herring, Massachusetts Institute of Technology
  • Henry Berglund, EarthScope