Comparison with GMAT

General Mission Analysis Tool (GMAT)

It is a free, open-source space mission analysis and design tool developed by NASA. GMAT is designed to support the modeling and simulation of spacecraft trajectories, including orbit determination, maneuver planning, and mission analysis. It provides a user-friendly interface for defining spacecraft dynamics, mission scenarios, and trajectory optimization.

Results

The following figures show the comparison between the results obtained from the 2BP model and GMAT (considering perturbations) for the same initial conditions. The results are for a LEO satellite called “XPOSAT” which was launched by ISRO in 2024.

The initial state in classical orbital elements is:

  • Semi-major axis (a): 7025.051 km
  • Eccentricity (e): 0.00233490
  • Inclination (i): 5.9310°
  • Right Ascension of Ascending Node (RAAN): 337.4084°
  • Argument of Periapsis (ω): 250.2758°
  • Initial True Anomaly (θ₀): 30.15°
Absolute Error in position magnitude

Figure 8.1: Absolute Error in position magnitude

Absolute Error in velocity magnitude

Figure 8.2: Absolute Error in velocity magnitude

Absolute Error in position (components)

Figure 8.3: Absolute Error in position (components)

Absolute Error in velocity (components)

Figure 8.4: Absolute Error in velocity (components)