Telescope

Initialize a Telescope object for adaptive optics simulations.

Parameters:

Name	Type	Description	Default
resolution	float	Resolution of the pupil mask (number of pixels across diameter).	required
diameter	float	Physical diameter of the telescope in meters.	required
samplingTime	float	Time step of the AO loop, used for updating atmospheric phase screens.	0.001
centralObstruction	float	Central obstruction diameter as a fraction of telescope diameter (0–1).	0
fov	float	Field of view in arcseconds.	0
pupil	bool or ndarray	User-defined pupil mask. If None, generates a circular pupil with optional obstruction.	None
pupilReflectivity	float or ndarray	Pupil reflectivity map or scalar. Defaults to 1.	1
logger	Logger	Logger instance for output. If None, a default logger is created.	None

Source code in SAOS/Telescope.py

def __init__(self,resolution:float,
             diameter:float,
             samplingTime:float=0.001,
             centralObstruction:float = 0,
             fov:float = 0,
             pupil:bool=None,
             pupilReflectivity:float=1,
             logger=None):
    """
    Initialize a Telescope object for adaptive optics simulations.

    Parameters
    ----------
    resolution : float
        Resolution of the pupil mask (number of pixels across diameter).
    diameter : float
        Physical diameter of the telescope in meters.
    samplingTime : float, optional
        Time step of the AO loop, used for updating atmospheric phase screens.
    centralObstruction : float, optional
        Central obstruction diameter as a fraction of telescope diameter (0–1).
    fov : float, optional
        Field of view in arcseconds.
    pupil : bool or np.ndarray, optional
        User-defined pupil mask. If None, generates a circular pupil with optional obstruction.
    pupilReflectivity : float or np.ndarray, optional
        Pupil reflectivity map or scalar. Defaults to 1.
    logger : logging.Logger, optional
        Logger instance for output. If None, a default logger is created.
    """

    if logger is None:
        self.queue_listerner = self.setup_logging()
        self.logger = logging.getLogger()
    else:
        self.external_logger_flag = True
        self.logger = logger

    self.isInitialized               = False                        # Resolution of the telescope
    self.resolution                  = resolution                   # Resolution of the telescope
    self.D                           = diameter                     # Diameter in m
    self.pixelSize                   = self.D/self.resolution       # size of the pixels in m
    self.centralObstruction          = centralObstruction           # central obstruction
    self.fov                         = fov                          # Field of View in arcsec converted in radian
    self.fov_rad                     = fov/206265                   # Field of View in arcsec converted in radian
    self.samplingTime                = samplingTime                 # AO loop speed
    self.user_defined_pupil          = pupil                        # input user-defined pupil
    self.pupilReflectivity           = pupilReflectivity            # Pupil Reflectivity <=> amplitude map

    self.tag                         = 'telescope'                  # tag of the object

    self.set_pupil()                                                # set the pupil

    self.isInitialized               = True

queue_listerner instance-attribute

queue_listerner = setup_logging()

logger instance-attribute

logger = getLogger()

external_logger_flag instance-attribute

external_logger_flag = True

resolution instance-attribute

resolution = resolution

D instance-attribute

D = diameter

pixelSize instance-attribute

pixelSize = D / resolution

centralObstruction instance-attribute

centralObstruction = centralObstruction

fov instance-attribute

fov = fov

fov_rad instance-attribute

fov_rad = fov / 206265

samplingTime instance-attribute

samplingTime = samplingTime

user_defined_pupil instance-attribute

user_defined_pupil = pupil

pupilReflectivity instance-attribute

pupilReflectivity = pupilReflectivity

tag instance-attribute

tag = 'telescope'

isInitialized instance-attribute

isInitialized = True

set_pupil

set_pupil()

Generate the pupil mask either from user input or by creating a circular aperture with optional central obstruction.

Updates the following: - self.pupil - self.pupilReflectivity - self.pixelArea - self.pupilLogical

Returns:

Type	Description
None

Source code in SAOS/Telescope.py

def set_pupil(self):
    """
    Generate the pupil mask either from user input or by creating a circular aperture
    with optional central obstruction.

    Updates the following:
    - self.pupil
    - self.pupilReflectivity
    - self.pixelArea
    - self.pupilLogical

    Returns
    -------
    None
    """
    # Case where the pupil is not input: circular pupil with central obstruction    
    if self.user_defined_pupil is None:
        D           = self.resolution+1
        x           = np.linspace(-self.resolution/2,self.resolution/2,self.resolution)
        xx,yy       = np.meshgrid(x,x)
        circle      = xx**2 + yy**2
        obs         = circle >= (self.centralObstruction*D/2)**2
        self.pupil  = circle < (D/2)**2 
        self.pupil  = self.pupil*obs
    else:
        self.logger.info('Telescope::set_pupil - User-defined pupil, the central obstruction will not be taken into account.')
        self.pupil  = self.user_defined_pupil.copy()        

    self.pupilReflectivity           = self.pupil.astype(float)*self.pupilReflectivity                    # A non uniform reflectivity can be input by the user
    self.pixelArea                   = np.sum(self.pupil)                                                 # Total number of pixels in the pupil area
    self.pupilLogical                = np.where(np.reshape(self.pupil,self.resolution*self.resolution)>0) # index of valid pixels in the pupil

apply_spiders

apply_spiders(
    angle, thickness_spider, offset_X=None, offset_Y=None
)

Add spiders to the telescope pupil mask.

Parameters:

Name	Type	Description	Default
angle	list of float	List of angles [deg] defining the spider orientation.	required
thickness_spider	float	Width of the spider arms in meters.	required
offset_X	list of float	X offsets per spider. Same length as angle.	None
offset_Y	list of float	Y offsets per spider. Same length as angle.	None

Returns:

Type	Description
None

Source code in SAOS/Telescope.py

def apply_spiders(self,angle,thickness_spider,offset_X = None, offset_Y=None):
    """
    Add spiders to the telescope pupil mask.

    Parameters
    ----------
    angle : list of float
        List of angles [deg] defining the spider orientation.
    thickness_spider : float
        Width of the spider arms in meters.
    offset_X : list of float, optional
        X offsets per spider. Same length as angle.
    offset_Y : list of float, optional
        Y offsets per spider. Same length as angle.

    Returns
    -------
    None
    """
    # Reset the pupil to the default one before adding the spiders
    self.set_pupil()

    if thickness_spider > 0:           
        pup = np.copy(self.pupil)

        max_offset = self.centralObstruction*self.D/2 - thickness_spider/2

        if offset_X is None:
            offset_X = np.zeros(len(angle))

        if offset_Y is None:
            offset_Y = np.zeros(len(angle))

        if np.max(np.abs(offset_X))>=max_offset or np.max(np.abs(offset_Y))>max_offset:
            self.logger.warning('Telescope::apply_spiders - The spider offsets are too large! Weird things could happen!')

        for i in range(len(angle)):
            angle_val = (angle[i]+90)%360
            x = np.linspace(-self.D/2,self.D/2,self.resolution)
            [X,Y] = np.meshgrid(x,x)
            X+=offset_X[i]
            Y+=offset_Y[i]

            map_dist = np.abs(X*np.cos(np.deg2rad(angle_val)) + Y*np.sin(np.deg2rad(-angle_val)))

            if 0<=angle_val<90:
                map_dist[:self.resolution//2,:] = thickness_spider
            if 90<=angle_val<180:
                map_dist[:,:self.resolution//2] = thickness_spider
            if 180<=angle_val<270:
                map_dist[self.resolution//2:,:] = thickness_spider
            if 270<=angle_val<360:
                map_dist[:,self.resolution//2:] = thickness_spider                
            pup*= map_dist>thickness_spider/2

        self.pupil = pup.copy()
        self.pupilReflectivity = self.pupil.astype(float) * self.pupilReflectivity
        self.pixelArea = np.sum(self.pupil)
        self.pupilLogical = np.where(np.reshape(self.pupil, self.resolution*self.resolution) > 0)

    else:
        self.logger.warning('Telescope::apply_spider - Thickness is <=0, returning default pupil.')

    return 

print_properties

print_properties()

Log and print key telescope properties: diameter, resolution, pixel size, surface area, central obstruction, and FOV.

Returns:

Type	Description
None

Source code in SAOS/Telescope.py

def print_properties(self):
    """
    Log and print key telescope properties: diameter, resolution, pixel size,
    surface area, central obstruction, and FOV.

    Returns
    -------
    None
    """        
    self.logger.info('%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% TELESCOPE %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%')
    self.logger.info('{: ^18s}'.format('Diameter')                     + '{: ^18s}'.format(str(self.D))                                        +'{: ^18s}'.format('[m]'   ))
    self.logger.info('{: ^18s}'.format('Resolution')                   + '{: ^18s}'.format(str(self.resolution))                               +'{: ^18s}'.format('[pixels]'   ))
    self.logger.info('{: ^18s}'.format('Pixel Size')                   + '{: ^18s}'.format(str(np.round(self.pixelSize,2)))                    +'{: ^18s}'.format('[m]'   ))
    self.logger.info('{: ^18s}'.format('Surface')                      + '{: ^18s}'.format(str(np.round(self.pixelArea*self.pixelSize**2)))    +'{: ^18s}'.format('[m2]'  ))
    self.logger.info('{: ^18s}'.format('Central Obstruction')          + '{: ^18s}'.format(str(100*self.centralObstruction))                   +'{: ^18s}'.format('[% of diameter]' ))
    self.logger.info('{: ^18s}'.format('Pixels in the pupil')          + '{: ^18s}'.format(str(self.pixelArea))                                +'{: ^18s}'.format('[pixels]' ))
    self.logger.info('{: ^18s}'.format('Field of View')                + '{: ^18s}'.format(str(self.fov))                                      +'{: ^18s}'.format('[arcsec]' ))
    self.logger.info('%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%')

setup_logging

setup_logging(logging_level=logging.WARNING)

Source code in SAOS/Telescope.py

def setup_logging(self, logging_level=logging.WARNING):
    #
    #  Setup of logging at the main process using QueueHandler
    log_queue = Queue()
    queue_handler = logging.handlers.QueueHandler(log_queue)
    root_logger = logging.getLogger()
    root_logger.setLevel(logging_level)  # Minimum log level

    # Setup of the formatting
    formatter = logging.Formatter(
        "%(asctime)s - %(levelname)s - %(message)s"
    )

    # Output to terminal
    console_handler = logging.StreamHandler()
    console_handler.setFormatter(formatter)

    # Qeue handler captures the messages from the different logs and serialize them
    queue_listener = logging.handlers.QueueListener(log_queue, console_handler)
    root_logger.addHandler(queue_handler)
    queue_listener.start()

    return queue_listener

__del__

__del__()

Source code in SAOS/Telescope.py

def __del__(self):
    if not self.external_logger_flag:
        self.queue_listerner.stop()