Obtaining the Space Indices
julia> using Datesjulia> using SpaceIndicesjulia> SpaceIndices.Scratch.clear_scratchspaces!(SpaceIndices)
After the initialization shown in Initialization of Space Indices, the user can obtain the space index value using the function:
space_index(::Val{:index}, jd::Number; kwargs...) -> Number
space_index(::Val{:index}, instant::DateTime; kwargs...) -> Numberwhere index is the desired space index and jd is the Julian Day to obtain the information. The latter can also be specified using instant, which is a DateTime object.
julia> SpaceIndices.init()[ Info: Downloading the file 'DTCFILE.TXT' from 'https://sol.spacenvironment.net/JB2008/indices/DTCFILE.TXT'... [ Info: Downloading the file 'SOLFSMY.TXT' from 'https://sol.spacenvironment.net/JB2008/indices/SOLFSMY.TXT'... [ Info: Downloading the file 'SW-All.csv' from 'https://celestrak.org/SpaceData/SW-All.csv'... [ Info: Downloading the file 'Hp30_ap30_complete_series.txt' from 'https://kp.gfz.de/app/files/Hp30_ap30_complete_series.txt'... [ Info: Downloading the file 'Hp60_ap60_complete_series.txt' from 'https://kp.gfz.de/app/files/Hp60_ap60_complete_series.txt'... [ Info: Downloading the file 'hpo_forecast_mean_bars_Hp30.json' from 'https://isdc-data.gfz.de/geomagnetism/HpoForecast/v0102/output/Hpo/json/hpo_forecast_mean_bars_Hp30.json'... [ Info: Downloading the file 'hpo_forecast_mean_bars_Hp60.json' from 'https://isdc-data.gfz.de/geomagnetism/HpoForecast/v0102/output/Hpo/json/hpo_forecast_mean_bars_Hp60.json'... [ Info: Downloading the file 'f107_observed_prediction_coefficients.csv' from 'https://raw.githubusercontent.com/JuliaSpace/SatelliteToolboxSpaceIndexSets/refs/heads/main/files/f107_observed_prediction_coefficients.csv'... [ Info: Downloading the file 'f107_adjusted_prediction_coefficients.csv' from 'https://raw.githubusercontent.com/JuliaSpace/SatelliteToolboxSpaceIndexSets/refs/heads/main/files/f107_adjusted_prediction_coefficients.csv'...julia> space_index(Val(:F10adj), DateTime(2020, 6, 19))70.2julia> space_index(Val(:F10adj), 2.4590195e6)70.2
The following space indices are currently supported:
| Space Index Set | Index | Description | Unit |
|---|---|---|---|
Celestrak | F10obs | Observed F10.7 (10.7-cm solar flux) | 10⁻²² W / (M² ⋅ Hz) |
F10obs_avg_center81 | Observed F10.7 (10.7-cm solar flux) averaged over 81 days centered | 10⁻²² W / (M² ⋅ Hz) | |
F10obs_avg_last81 | Observed F10.7 (10.7-cm solar flux) averaged over 81 last days | 10⁻²² W / (M² ⋅ Hz) | |
F10adj | Adjusted F10.7 (10.7-cm solar flux) | 10⁻²² W / (M² ⋅ Hz) | |
F10adj_avg_center81 | Observed F10.7 (10.7-cm solar flux) averaged over 81 days centered | 10⁻²² W / (M² ⋅ Hz) | |
F10adj_avg_last81 | Observed F10.7 (10.7-cm solar flux) averaged over 81 last days | 10⁻²² W / (M² ⋅ Hz) | |
Ap | Ap index computed every three hours | ||
Ap_daily | Daily Ap index | ||
Kp | Kp index computed every three hours | ||
Kp_daily | Daily Kp index | ||
Cp | Daily planetary character figure | ||
C9 | Daily magnetic index on Cp basis | ||
ISN | International sunspot number | ||
BSRN | Bartels solar rotation number | ||
ND | Number of days into Bartels solar rotation cycle | Days | |
JB2008 | DTC | Exospheric temperature variation caused by the Dst index | K |
S10 | EUV index (26-34 nm) scaled to F10.7 | 10⁻²² W / (M² ⋅ Hz) | |
M10 | MG2 index scaled to F10.7 | 10⁻²² W / (M² ⋅ Hz) | |
Y10 | Solar X-ray & Lya index scaled to F10.7 | 10⁻²² W / (M² ⋅ Hz) | |
S81a | 81-day averaged EUV index (26-34 nm) scaled to F10.7 | 10⁻²² W / (M² ⋅ Hz) | |
M81a | 81-day averaged MG2 index scaled to F10.7 | 10⁻²² W / (M² ⋅ Hz) | |
Y81a | 81-day averaged solar X-ray & Lya index scaled to F10.7 | 10⁻²² W / (M² ⋅ Hz) | |
Hpo | Hp30 | Geomagnetic index with 30-minute resolution | |
ap30 | Linear geomagnetic activity index (30-minute) | ||
Hp60 | Geomagnetic index with 60-minute resolution | ||
ap60 | Linear geomagnetic activity index (60-minute) | ||
Dst | Dst | Disturbance Storm Time index (hourly) | nT |
SatelliteToolboxSpaceIndexSets | F10obs_predicted | Predicted observed F10.7 (10.7-cm solar flux) from a harmonic model | 10⁻²² W / (M² ⋅ Hz) |
F10adj_predicted | Predicted adjusted F10.7 (10.7-cm solar flux, adjusted to 1 AU) from a harmonic model | 10⁻²² W / (M² ⋅ Hz) |
The Dst index set is not included in the default SpaceIndices.init() call. It must be initialized separately using SpaceIndices.init(SpaceIndices.Dst). See Initialization of Space Indices for details.
The F10obs_predicted and F10adj_predicted indices are long-term predictions obtained from harmonic models with six harmonics fitted to the observed and adjusted F10.7 data since 1957-10-02, respectively. They only capture the mean solar cycle behavior and must not be used as a short-term forecast of the solar activity.
Available Timespan
Some indices can inform the timespan in which their data is available using the function:
SpaceIndices.timespan(::Val{:index}) -> Union{Nothing, NTuple{2, Float64}}It returns a tuple with the initial and final Julian days (UTC) in which the data for the space index is available, or nothing if the index does not provide this information. If a tuple is returned, it is guaranteed that calling space_index for the same index does not fail for any instant inside the returned interval.
julia> ts = SpaceIndices.timespan(Val(:F10obs))(2.4361128333333335e6, 2.4613218333333335e6)julia> julian2datetime.(ts)(DateTime("1957-10-01T08:00:00"), DateTime("2026-10-08T08:00:00"))julia> SpaceIndices.timespan(Val(:F10obs_predicted)) === nothingtrue