TechnicalSGP4
Simplified General Perturbations 4
The standard propagation model used with TLE data to predict satellite positions.
SGP4 is the mathematical model for propagating TLE orbital data.
Characteristics
- Used with Two-Line Elements
- Accounts for atmospheric drag, J2, etc.
- Accuracy degrades over time
- Free and widely available
Limitations Position accuracy ~1-3 km at epoch, degrading to ~10+ km over days.