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Module gps

celestial_time::scales

Module gps 

Source
Expand description

GPS Time scale.

GPS Time is the time standard used by GPS satellites. It is synchronized with TAI but offset by exactly 19 seconds: TAI = GPS + 19s.

§Background

GPS Time started on January 6, 1980 at 00:00:00 UTC. At that moment, GPS and UTC were synchronized, and TAI was already 19 seconds ahead of UTC. GPS does not include leap seconds, so the TAI-GPS offset remains constant while UTC-GPS diverges with each new leap second.

As of 2024, UTC is 18 seconds behind GPS (37 seconds behind TAI).

§Representation

Internally stored as a split Julian Date for nanosecond-level precision. See JulianDate for details on the two-part representation.

§Usage

use celestial_time::{GPS, JulianDate};

// From calendar date
let gps = celestial_time::scales::gps::gps_from_calendar(2024, 3, 15, 12, 0, 0.0);

// From Julian Date
let gps = GPS::from_julian_date(JulianDate::j2000());

// Arithmetic
let later = gps.add_seconds(3600.0);
let next_day = gps.add_days(1.0);

§Conversions

GPS converts to/from TAI via a fixed 19-second offset. See scales::conversions::gps_tai for the conversion traits.

Structs§

GPS
GPS Time representation.

Functions§

gps_from_calendar
Creates GPS time from calendar components.