Atmospheric Simulation#

phobos.modules.atmosphere.atmo_screen_kolmogorov(
size,
physical_size,
r0,
L0,
fc=25,
correc=1.0,
)[source]#

Generate a Kolmogorov-Von Karman type atmospheric phase screen.

Parameters:

  • size (int) – Screen size in pixels (size x size)

  • physical_size (float) – Physical extent of the screen in meters

  • r0 (float) – Fried parameter in meters (at a reference wavelength)

  • L0 (float) – Outer scale in meters

  • fc (float, optional) – Cutoff frequency for AO correction (in cycles across the screen)

  • correc (float, optional) – Amplitude correction factor up to fc

Returns:

Phase screen in radians (size x size)

Return type:

ndarray

phobos.modules.atmosphere.get_delays(
n_telescopes=4,
telescope_diameter=1.8,
telescope_positions=None,
r0=0.8,
L0=25.0,
wavelength=1.65e-06,
wind_speed=10.0,
wind_direction=45.0,
screen_size=512,
screen_physical_size=None,
time_step=0.1,
n_steps=100,
demo=False,
save_as=None,
)[source]#

Calculate atmospheric phase delays for multiple telescopes.

The atmosphere follows a Kolmogorov-Von Karman model that evolves in time by moving with a given wind speed and direction (frozen flow turbulence model).

Parameters:

  • n_telescopes (int, optional) – Number of telescopes (default: 4)

  • telescope_diameter (float, optional) – Telescope diameter in meters (default: 1.8 m)

  • telescope_positions (ndarray, optional) – Telescope positions in meters, array of shape (n_telescopes, 2). If None, uses a square configuration. (default: None)

  • r0 (float, optional) – Fried parameter in meters at reference wavelength 1.55 μm. Typical values at 1.55 μm: 0.5 m (poor), 0.8 m (average), 1.0 m (good), 1.5 m (excellent) (default: 0.8)

  • L0 (float, optional) – Outer scale of turbulence in meters (default: 25.0)

  • wavelength (float, optional) – Observation wavelength in meters (default: 1.65e-6, H-band)

  • wind_speed (float, optional) – Wind speed in m/s (default: 10.0)

  • wind_direction (float, optional) – Wind direction in degrees (0° = East, 90° = North) (default: 45.0)

  • screen_size (int, optional) – Phase screen size in pixels (default: 512)

  • screen_physical_size (float, optional) – Physical screen size in meters. If None, automatically calculated from telescope positions and diameter with 20% margin (default: None)

  • time_step (float, optional) – Time step in seconds (default: 0.1)

  • n_steps (int, optional) – Number of time steps to calculate (default: 100)

  • demo (bool, optional) – (default: False)

  • save_as (str, optional) – Path to save the animation as a GIF (e.g. “atmo.gif”). Only used if demo=True. (default: None)

Returns:

  • delays (ndarray) – Phase delays for each telescope in nanometers. Shape: (n_steps, n_telescopes)

  • times (ndarray) – Corresponding times in seconds. Shape: (n_steps,)

Examples

>>> # Simple configuration with 4 telescopes
>>> delays, times = get_delays(n_telescopes=4, demo=True)

>>> # Custom configuration
>>> positions = np.array([[0, 0], [10, 0], [10, 10], [0, 10]])
>>> delays, times = get_delays(
...     telescope_positions=positions,
...     wind_speed=15.0,
...     wind_direction=30.0,
...     demo=False
... )