CGGTTS

Rust package to parse and generate CGGTTS data.

CGGTTS is a file format designed to describe a local clock state compared to GNSS time systems.
Exchanging CGGTTS files allows comparison of remote clocks by means of common satellite clocks in sight.
This is called the "common view" time transfer technique.

CGGTTS is specified by the Bureau International des Poids & des Mesures (BIPM): CGGTTS 2E specifications

This library only supports revision 2E, and will reject other revisions.

Set of tools

• cggtts is the main library. Compile it with the scheduler option to unlock full support of CGGTTS data production
• cggtts-cli is an application to analyze one or compare two CGGTTS files.
  Download its latest release from the github portal.

Ecosystem

CGGTTS heavily relies on Hifitime for accurate Epoch representation and Timescales knowledge. Check out Christopher's amazing libraries right here.

The RNX2CGGTTS application is the goto application when it comes to generate CGTTTS files. Use it to generate synchronous CGGTTS tracks from coherent RINEX contexts.
Checkout the RINEX Wiki for examples of CGGTTS file exchanges.

CGGTTS track scheduling

If you compiled the crate with the scheduler feature, you can access the Scheduler structure that helps you generate synchronous CGGTTS tracks.

Synchronous CGGTTS is convenient because it allows direct exchange of CGGTTS files and therefore, direct remote clocks comparison.

The Scheduler structure works according to the BIPM definitions but we allow for a different tracking duration. The default being 980s, you can use shorter tracking duration and faster CGGTTS generation. You can only modify the tracking duration if you can do so on both remote clocks, so they share the same production parameters at all times.

System Time delays

A built in API allows accurate system delay description as defined in CGGTTS.

CGGTTS-CLI

A command line application is developed to process one or two CGGTTS file for clock comparison.