Models

Dynamics

Functions

fixed_centres([Gconst, masses, positions])	Produces the expressions for the dynamics in a fixed-centres problem.
pendulum([gconst, length])	Produces the expression for the dynamics of the simple pendulum.

Coordinate transformations

Functions

cart2geo(xyz[, ecc2, R_eq, n_iters])	Transform Cartesian coordinates into geodetic coordinates.
geo2cart(geo[, ecc2, R_eq])	Transform geodetic coordinates into Cartesian coordinates.
rot_fk5j2000_icrs(xyz)	Rotation from FK5 to ICRS.
rot_icrs_fk5j2000(xyz)	Rotation from ICRS to FK5.
rot_itrs_icrs(xyz[, time_expr, thresh, eop_data])	Rotation from ITRS to ICRS.
rot_icrs_itrs(xyz[, time_expr, thresh, eop_data])	Rotation from ICRS to ITRS.

Time transformations

Functions

delta_tdb_tt([time_expr])

Difference between TDB and TT.

Attributes

delta_tt_tai

Difference between TT and TAI.

Atmospheric models

Functions

nrlmsise00_tn(geodetic, f107, f107a, ap, ...)	Produces the expression of the thermospheric density as a function of geodetic coordinates and weather indices.
jb08_tn(geodetic, f107, f107a, s107, s107a, ...)	Produces the expression of the thermospheric density as a function of geodetic coordinates and weather indices.

Earth orientation and space weather

Functions

era([time_expr, eop_data])	Earth rotation angle.
erap([time_expr, eop_data])	Derivative of the Earth rotation angle.
pm_x([time_expr, eop_data])	Polar motion (x component).
pm_xp([time_expr, eop_data])	Derivative of the polar motion (x component).
pm_y([time_expr, eop_data])	Polar motion (y component).
pm_yp([time_expr, eop_data])	Derivative of the polar motion (y component).
dX([time_expr, eop_data])	Correction to the Earth's precession/nutation model (x component).
dXp([time_expr, eop_data])	Derivative of the correction to the Earth's precession/nutation model (x component).
dY([time_expr, eop_data])	Correction to the Earth's precession/nutation model (y component).
dYp([time_expr, eop_data])	Derivative of the correction to the Earth's precession/nutation model (y component).
Ap_avg([time_expr, sw_data])	Average of the geomagnetic Ap indices.
f107([time_expr, sw_data])	Observed 10.7-cm solar radio flux.
f107a_center81([time_expr, sw_data])	Average of the 10.7-cm solar radio flux.

Analytical theories and models

Functions

iau2006([time_expr, thresh])	IAU2000/2006 precession-nutation theory.
egm2008_pot(xyz, n, m[, mu, a])	Geopotential (EGM2008).
egm2008_acc(xyz, n, m[, mu, a])	Gravitational acceleration (EGM2008).

SGP4 propagation

Classes

sgp4_propagator_dbl	SGP4 propagator (double precision).
sgp4_propagator_flt	SGP4 propagator (single precision).

Functions

sgp4([inputs])	Produces the expressions for the SGP4 propagator.
gpe_is_deep_space(n0, e0, i0)	Check whether a GPE is deep-space.
sgp4_propagator(sat_list[, diff_order])	Construct an SGP4 propagator.