tobari

Earth environment models for orbital mechanics.

Atmosphere

Provides pluggable atmospheric density models behind the AtmosphereModel trait.

• Exponential — US Standard Atmosphere 1976, altitude-only (simplest, no epoch needed)
• HarrisPriester — diurnal density variation using Sun position
• Nrlmsise00 — full empirical model driven by solar and geomagnetic activity indices

All models implement AtmosphereModel and can be swapped at runtime via Box<dyn AtmosphereModel>.

Magnetic field

Provides pluggable geomagnetic field models behind the magnetic::MagneticFieldModel trait.

• magnetic::TiltedDipole — simple tilted dipole approximation (fastest)

Space weather

The space_weather module defines SpaceWeather conditions and the SpaceWeatherProvider trait for supplying time-varying solar/geomagnetic data. CssiSpaceWeather parses CelesTrak CSSI-format files and (with the fetch feature) downloads them automatically with local caching.

Data attribution

Space weather indices are sourced from:

• Kp/Ap geomagnetic indices: GFZ Helmholtz Centre for Geosciences (CC BY 4.0)
• F10.7 solar radio flux: NOAA SWPC / NRCan DRAO (public domain)
• Aggregated and distributed by CelesTrak (https://celestrak.org/SpaceData/)

Traits

Name	Description
MagneticFieldModel	A geomagnetic field model.
SpaceWeatherProvider	Provider of space weather data for a given epoch.
AtmosphereModel	An atmospheric density model.

Structs

Name	Description
CssiDailyRecord	alloc — A single daily record from CSSI space weather data.
CssiData	alloc — Parsed CSSI space weather data, sorted by date.
CssiSpaceWeather	alloc — Space weather provider backed by CSSI historical data.
Exponential	Piecewise exponential atmosphere model based on US Standard Atmosphere 1976.
HarrisPriester	Harris-Priester atmospheric density model.
TiltedDipole	Tilted dipole geomagnetic field model with ECEF-fixed axis.
GaussCoefficients	Gauss coefficient set for a single epoch.
Igrf	IGRF (International Geomagnetic Reference Field) model.
MagneticFieldInput	Pre-computed input for magnetic field evaluation.
Nrlmsise00Output	Full output of the NRLMSISE-00 model.
Nrlmsise00Input	Input parameters for a single NRLMSISE-00 evaluation.
Nrlmsise00	NRLMSISE-00 empirical atmosphere model.
SpaceWeather	Space weather conditions at a given epoch.
ConstantWeather	Constant space weather — returns the same F10.7 and Ap for all epochs.
AtmosphereInput	Pre-computed input for atmospheric density evaluation.

Enums

Name	Description
CssiParseError	alloc — Parse error for CSSI space weather files.
OutOfRangeBehavior	alloc — Behavior when the requested epoch is outside the data range.
GfzParseError	alloc — Parse error for GFZ space weather files.
SpaceWeatherFormat	alloc — Detected space weather data format.

Functions

Name	Description
density	Compute atmospheric density [kg/m³] at the given altitude [km].
parse_gfz	alloc — Parse GFZ Kp_ap_Ap_SN_F107_*.txt format into [CssiData].
detect_format	alloc — Detect whether text is CSSI or GFZ format.
simple_eci_to_geodetic_latlon	Convert a simple-path ECI position to WGS-84 geodetic latitude and
precise_gcrs_to_geodetic_latlon	Convert a GCRS position + UTC epoch + EOP provider to WGS-84
epoch_to_day_of_year_and_ut	Convert epoch to (day_of_year, ut_seconds).
local_solar_time	Compute local apparent solar time [hours].

Type Aliases

Name	Description
IgrfCoeffArray	Fixed-size array type for IGRF Gauss coefficients.

Constants

Name	Description
TEMP_COEFFICIENTS	Exospheric temperature variation coefficients (150 terms).
DENSITY_COEFFICIENTS	Density variation coefficients for each species (9 species x 150 terms).
GRADIENT_COEFFICIENTS	Temperature gradient (S-parameter) variation coefficients (150 terms).
CORRECTION_PARAMS	Composition and turbopause correction parameters (2 x 25 terms).
TEMP_BOUNDARY	Temperature boundary and reference values (50 terms).
DENSITY_BOUNDARY	Density boundary parameters per species (8 species x 10 terms).
TEMP_NODE_COEFFICIENTS	Temperature node correction coefficients (4 nodes x 100 terms).
MID_ATMO_COEFFICIENTS	Middle atmosphere variation coefficients (10 x 100 terms).
SAM_COEFFICIENTS	Semiannual multiplier coefficients (100 terms).
MID_ATMO_AVERAGES	Middle atmosphere average values (10 terms).