#include <novas.h>

Data Fields
enum novas_accuracy	accuracy
	NOVAS_FULL_ACCURACY or NOVAS_REDUCED_ACCURACY.

double	beta
	Observer relativistic β rel SSB.

double	deps0
	[rad] Modeled Earth orientation ε (not including polar wobble)

double	dpsi0
	[rad] Modeled Earth orientation ψ (not including polar wobble)

double	dx
	[mas] Polar wobble parameter dx.

double	dy
	[mas] Polar wobble parameter dy.

double	earth_pos [3]
	[AU] Earth's geometric position, rel SSB.

double	earth_vel [3]
	[AU/day] Earth's velocity, rel SSB.

double	ee
	[rad] Equation of the equinoxes

double	era
	[deg] Earth Rotation Angle (ERA);

double	gamma
	Observer Lorentz factor Γ rel SSB.

novas_matrix	gcrs_to_cirs
	GCRS to CIRS conversion matrix.

double	gst
	[h] Greenwich (Apparent) Sidereal Time (GST / GAST)

novas_matrix	icrs_to_j2000
	ICRS to J2000 matrix.

double	mobl
	[rad] Mean obliquity

novas_matrix	nutation
	nutation matrix (Lieske 1977 method)

double	obs_pos [3]
	[AU] Observer position rel. to barycenter

double	obs_vel [3]
	[AU/day] Observer movement rel. to barycenter

observer	observer
	The observer location, or NULL for barycentric.

novas_planet_bundle	planets
	Planet positions and velocities.

novas_matrix	precession
	precession matrix

uint64_t	state
	An internal state for checking validity.

double	sun_pos [3]
	[AU] Sun's geometric position, rel SSB.

double	sun_vel [3]
	[AU/day] Sun's velocity, rel SSB.

novas_timespec	time
	The instant of time for which this observing frame is valid.

double	tobl
	[rad] True obliquity

double	v_obs
	[AU/day] Magnitude of observer motion rel. to barycenter

Detailed Description

A set of parameters that uniquely define the place and time of observation. The user may initialize the frame with novas_make_frame(). Once the observer frame is set up, it can be used repeatedly to perform efficient calculations of multiple objects in the coordinate system of choice, much faster than what place() can do. Frames also allow for transforming coordinates calculated for one coordinate syste, into another coordinate system with little effort.

You should never set or change fields in this structure manually. Instead the structure should always be initialized by an appropriate call to novas_make_frame(). After that you may change the observer location, if need be, with novas_change_observer().

The structure may expand with additional field in the future. Thus neither its size nor its particular layout should be assumed fixed over SuperNOVAS releases.

Since: 1.1

See also: novas_make_frame(); novas_change_observer()

The documentation for this struct was generated from the following file:

include/novas.h

Data Fields

Detailed Description