gLAB

Interactive educational multipurpose package to process and analyse GNSS data, i.e., a GNSS positioning simulator.

<p align="center"> <img src="https://github.com/user-attachments/assets/938b3cc9-8514-4109-9187-f470e91bee35"> </p>

Context: any version of the gLAB software can be downloaded here. However, in none of these links you will obtain the tutorial datafiles. Such a material is packaged in the GNSS tutoral link, together with the gLAB source code in a tarball file (see Software and Data Files [Linux] for Linux). On the one hand, at the time I am writing it (April 2024) , the gLAB source code packaged in this tarball is the version 5.2, which didn't work on Linux. On the other hand, the latest version of gLAB at the time of writing it (v5.5.1) worked perfectly on Linux.

Therefore, in order to create a straightfoward path to use any gLAB version with the computation homeworks, I've created this repository, which contains both the version v5.5.1 for Linux and the tutorial material.

Branches

• source-code-v5.5.1: contains the source code for gLAB version v5.5.1, but with a minor correction in the Makefile (see its README.md)
• tutorials: contains the computational homeworks that were retreived in previous version of gLAB.
• main: contains both contents plus install.sh, which is used to install it seamlessly.

Installing and usage

• To install glab, run ./install.sh. It should generate gLAB_linux and gLAB_linux_multithread. If it doesn't work, see README_install.txt.
• Use gLAB_GUI_64 for gLAB with GUI (on a 64-bits computer architecture) or gLAB_linux for the command line approach.

Directory structure

• FILES/: Contains the backup gzip files for each tutorial in TUTX/. You should not remove these files as ntpd_tutX.sh decompresses them to create new WORK/TUTX/ directories with the simulation results.
• PROG/:
  • Each TUTX/ directory just contains configuration plus symlink to gLAB executable.
• WORK/: Contains the unzipped files and the simulation results for each tutorial in TUTX. This directory is ignored by git as it contains large files that are result of simulation. Possible file types that you might find in each TUTX/ dir:
  • RINEX -> <sta><Doy>0.<yy><type>
    • <sta>: Station name.
    • <Doy>: Day of year.
    • <yy>: Year.
    • <type>: o -> observation RINEX file; n -> navigation RINEX file Example: amc3030.03o is the observation RINEX file for the amc station, on October 30th, 2003.
  • precise orbits & clocks -> .sp3 extension
  • Antenna Phase Center (APC) -> .atx.
  • Precise receiver coordinates -> .snx.
• ntpd_tutX.sh: Unix Shell script to run tutorial X. It basically creates WORK/TUTX/, and copies the config files from PROG/TUTX/ and data files from FILES/TUTX/ to it.