README for GEOSPACE Orbit Plots (most recent 90 day plots are updated daily)

Orbit plots are created at an 8 hour cadence in both GSE and SM coordinates.

1. The GSE plots are x-y orbit projections +/-30 RE in the equatorial plane.
2. The SM plots are x-y orbit projections +/-12 RE in the equatorial plane.

Only data that resides in the (SSCWeb database) are plotted. The plotting code calls the SSCWeb web-services API:
1. Makes a query of all spacecraft and their time ranges in the SSCWeb database
2. For time range of the plot, the target spacecraft within that time range are plotted
3. The target spacecraft are key NASA/ESA/JAXA missions plus GOES

Currently the target NASA/ESA/JAXA spacecraft are RBSPA, RBSPB, MMS1, CLUSTER4, GEOTAIL, ARASE, THEMIS-A, THEMIS-D, THEMIS-E.

For spacecraft flying in a constellation like MMS and CLUSTER only one spacecraft is selected the function sab_get_satinfo.pro contains this list and would have to be modified to add new spacecraft.

The dots on each orbit are spaced by 2 hours. The color assigned to each spacecraft is automatic can vary as new missions begin or old missions end.

The model magnetopause[1] and bow shock[2] are parameterized by Solar Wind and IMF. Solar Wind dynamic pressure, speed, proton density, and IMF used in the models, are from OMNI data[2] if available. If OMNI solar wind is not available nominal values are used 2.6 nPa, 8 cm^{-3}, 400 km/s, [-4, 4, 0] nT for Solar Wind dynamic pressure, speed, proton density, and IMF respectively.

Both the model Bow Shock&Magnetopause are corrected for aberration: atan(30 [km/s]/Solar Speed [km/s]). Note on the SM plot the MP and BS locations are only correct when the dipole tilt angle is 0 degrees.

On the GSE plot the dashed lines outside the bow shock connecting to the bow shock are in the direction of the IMF Bx, By, the bow shock normal is shown to help indicate whether that area of the bow shock is quasi-parallel or perpendicular.

Currently the plots are generated once a week over -/+ 90 day, interval, the -90 days to ensure that the OMNI data will be updated.

References
[1] Chao, J.K., D.J. Wu, C.-H. Lin, Y.-H. Yang, X.Y. Wang, M. Kessel, S.H. Chen, R.P. Lepping (2002), Models for the size and shape of the earth's magnetopause and bow shock, Pergamon, Volume 12, Pages 127-135, ISSN 0964-2749, ISBN 9780080440576, https://doi.org/10.1016/S0964-2749(02)80212-8.
[2] Papitashvili, Natalia E.; & King, Joseph H. (2020). OMNI Combined Heliopheric Observations (COHO), Merged Magnetic Field, Plasma and Ephermeris, Definitive Hourly Data [Data set]. NASA Space Physics Data Facility. https://doi.org/10.48322/6ffx-3441. Accessed on 2025-May-1.
[3] Shue, J.-H., et al. (1998), Magnetopause location under extreme solar wind conditions, J. Geophys. Res., 103(A8), 17691–17700, doi:10.1029/98JA01103.

Authors and curators:

Last updated: 2025