A Survey of Current Operations-Ready Thermospheric Density Models for Drag Modeling in LEO Operations

Area of Science:

• Space physics
• Aerospace engineering
• Satellite operations

Background:

• Atmospheric drag significantly impacts Low Earth Orbit (LEO) satellite trajectory predictions.
• The US Government's High Accuracy Satellite Drag Model (HASDM) is not publicly available, necessitating alternatives for commercial operators.
• Accurate thermospheric density models are crucial for collision risk assessment and operational decision-making in LEO.

Purpose of the Study:

• To evaluate and compare four operations-ready, open-source thermospheric density models for use in LEO.
• To provide satellite operators with performance data, computation times, and implementation guidance for these models.
• To inform the selection of state-of-the-art density models for improved satellite trajectory predictions.

Main Methods:

• Evaluated Drag Temperature Model (DTM), Jacchia-Bowman 2008 (JB2008), NRLMSIS 2.0, and TIE-GCM models.
• Compared model performance against global HASDM and local GRACE-FO and Swarm satellite densities.
• Analyzed computation time, space weather input requirements, and implementation considerations for each model.

Main Results:

• Performance metrics, computation times, and space weather dependencies of four open-source models are detailed.
• Comparisons reveal the strengths and weaknesses of each model against operational benchmarks.
• First-time public comparison of HASDM and Whole Atmosphere Model and Ionosphere Plasmasphere Electrodynamics (WAM-IPE) nowcast and forecast densities are presented.

Conclusions:

• Open-source thermospheric density models offer viable alternatives to proprietary US Government models for LEO operations.
• Informed selection of density models can significantly enhance trajectory prediction accuracy and operational safety.
• This research aids satellite operators in updating legacy systems with advanced, publicly available tools.