iers.c File Reference

Macros
#define	_GNU_SOURCE
	fmemopen (before glibc 2.10)

Functions
int	novas_fetch_eop (double jd, long timeout_millis, novas_eop *eop)
	Obtains interpolated Earth Orientation Parameter data from the International Earth Rotation and Reference Systems Service (IERS).
int	novas_fetch_eop_unix (time_t t, long timeout_millis, novas_eop *eop)
	Obtains interpolated Earth Orientation Parameter data from the International Earth Rotation and Reference Systems Service (IERS) around the current system time, using the rapid service data (finals.all).
int	novas_get_eop_itrf_year (enum novas_eop_series series)
	Returns the ITRF realization year for a given IERS Earth Orientation Parameter (EOP) series.
const char *	novas_get_eop_url (enum novas_eop_series series)
	Returns the URL currently configured for a given IERS Earth Orientation Parameter (EOP) series.
int	novas_is_auto_fetch_eop ()
	Checks if automatic fetching of Earth Orientation Parameter values from IERS is allowed.
int	novas_lookup_leap (time_t t)
	Returns the leap seconds for the given UNIX timestamp, based either on a locally supplied leap seconds list (see novas_set_leap_list()), or else from data obtained as needed from IERS (provided that fetching it is allowed).
void	novas_reset_eop ()
	Releases resources used by URL handles used for obtaining Earth Orientation Parameter (EOP) data from the International Earth Rotation and Reference Systems Service (IERS), including the leap seconds list supplied earlier or obtained from IERS.
int	novas_set_auto_fetch_eop (int enabled)
	Disable or Re-enabled the automatic fetching of Earth Orientation Parameter values from IERS, when these are left undefined (NAN) when initializing astrometric time or observing frame instances.
int	novas_set_eop_url (enum novas_eop_series series, int itrf_year, const char *url)
	Specify a URL to use for a given IERS Earth Orientation Parameter (EOP) series.
int	novas_set_leap_list (const char *filename)
	Specifies a local file containing the official leap seconds list, i.e.

Detailed Description

Date

Created on Apr 18, 2026

Author

Attila Kovacs

Functions to obtain and manage Earth Orientation data from the International Earth Rotation and Reference Systems Service (IERS) via HTTPS, or using other (remote or local) URLs.

The functions in this module are generally thread-safe. That is, you may call all functions from concurrent threads without data corruption. However, note that the EOP resources (URLs and/or local files), and the setting that enables/disables automatic fetching, are global settings. Thus, changing these in one thread will effect subsequent EOP fetch calls in other threads also.

See also

Earth orientation

Macro Definition Documentation

_GNU_SOURCE

#define _GNU_SOURCE

fmemopen (before glibc 2.10)