Simulator

This module defines the main interface to run orbit simulation. It supports both 2D (polar) and 3D (spherical) modes. Outputs are written to files for later use in prediction and visualization modules.

def run_simulator(mode, H_dark=20_000, 
                  recorded_times=np.linspace(0, 6000, 6001), 
                  radar_angle=np.pi/2,
                  radar_noise_base=100, 
                  radar_noise_scalefactor=0.05, 
                  input_path=None, 
                  output_path=None):
    ...

  • Purpose: Simulates the motion of a satellite and generates trajectory.

  • Parameters:

    • mode (str): Simulation mode, determines which variant of the trajectory generation and radar system to use. Typically '1D', '2D', or '3D'.

    • H_dark (float, default=20000): Altitude of radar stations above Earth’s surface (in meters).

    • recorded_times (np.ndarray): Array of timestamps at which the satellite’s true position is computed (e.g., 0 to 6000 seconds at 1-second intervals).

    • radar_angle (float, default=π/2): Field-of-view angle of each radar station (in radians), used in visibility checks.

    • radar_noise_base (float, default=100): Base level of Gaussian noise to add to radar measurements.

    • radar_noise_scalefactor (float, default=0.05): Factor scaling noise based on distance or angle.

    • input_path (str or None): Path to write the ground-truth (noise-free) trajectory data.

    • output_path (str or None): Path to write the noisy radar measurement data.

  • Implementation:

    • Generate True Trajectory:

      • Uses NumericalIntegrator.Integrator with the selected mode.

      • Simulates the satellite’s physical trajectory in polar or spherical space.

      • Writes to input_path using a mode-specific file writer (e.g., write_to_file_2D).

    • Setup Radar Stations:

      • Calls distribute_radarsMODE() (e.g., distribute_radars3D) to position radars.

      • Initializes radar objects with angle-of-view and noise characteristics.

    • Simulate Radar Measurements:

      • Each radar records satellite positions at given times if within view.

      • Measurement noise is added to simulate real-world uncertainty.

    • Aggregate and Write Noisy Data:

      • Combines radar data into a unified noisy trajectory.

      • Writes to output_path using the same file writer.