The objective of the TOLEOS project is the production of thermosphere density and crosswind observations derived from the accelerometer measurements of the CHAMP, GRACE, and GRACE-FO missions.
The new GRACE and GRACE-FO data are now available on our web server.
Top: Altitude evolution of accelerometer-carrying satellites launched since 2000. Colour indicates published data, while grey indicates unprocessed data (figure updated in January 2025). Bottom: Solar activity as indicated by the F10.7 solar radio flux index. The database spans now two solar cycles.
Detailed and accurate models of the satellite's geometry form the basis for aerodynamic and radiation pressure modelling. The geometry models are published as STL files here.
The flow of atoms and molecules around the satellite is simulated with the SPARTA DSMC code developed by Sandia National laboratories, taking into account the gas-surface interactions. The aerodynamic models are available as look-up tables here.
The effect of radiation pressure is modelled using ray tracing. Millions of light rays illuminate the satellite from every direction to simulate radiation pressure, accounting for the thermo-optical properties of the surfaces. The simulation results are stored as look-up tables, available here.
Project lead, accelerometer, density and crosswind data processing
Density and crosswind data validation
Validation of radiation pressure modelling
Density and crosswind data validation
TU Delft
Kluyverweg 1
2629 HS Delft
The Netherlands
AI Website Maker