Source code for coolest.template.classes.observation
__author__ = 'aymgal'
from typing import Union
from coolest.template.classes.grid import PixelatedRegularGrid
from coolest.template.classes.noise import Noise
from coolest.template.classes.base import APIBaseObject
[docs]
class Observation(APIBaseObject):
"""Defines the observation itself, that is the image pixels,
the exposure time, the noise model and/or properties, the magnitude
zero-point and sky brightness.
Parameters
----------
pixels : PixelatedRegularGrid, optional
Regular 2D Grid instance for the observed / mock data pixels, by default None
noise : Noise, optional
Instance of a Noise object associated with the modeling
of the data pixels, by default None
mag_zero_point : float, optional
Zero-point magnitude, which corresponds to the 1 electron per second
hitting the detector (given in mag), by default None
mag_sky_brightness : float, optional
Magnitude due to sky brightness (given in mag per arcsec^2),
by default None
"""
def __init__(self,
pixels: PixelatedRegularGrid = None, # can be None for mock generation
exposure_time: Union[float, PixelatedRegularGrid] = None,
noise: Noise = None,
mag_zero_point: float = None,
mag_sky_brightness: float = None,
# time_delays: list = None,
# magnification_ratios: list = None
) -> None:
if pixels is None:
pixels = PixelatedRegularGrid()
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self.exposure_time = exposure_time
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self.mag_zero_point = mag_zero_point # magnitude zero-point (corresponds to 1 electron per second on the detector)
[docs]
self.mag_sky_brightness = mag_sky_brightness # sky brightness (magnitude per arcsec^2)
if noise is None:
noise = Noise()
# self.time_delays = time_delays
# self.magnification_ratios = magnification_ratios
super().__init__()
[docs]
def check_consistency_with_instrument(self, instrument):
"""Checks that the data image is consistent with instrument properties"""
width = abs(self.pixels.field_of_view_x[1] - self.pixels.field_of_view_x[0])
height = abs(self.pixels.field_of_view_y[1] - self.pixels.field_of_view_y[0])
num_pix_ra = round(width / instrument.pixel_size)
error_message_ra = f"Number of pixels along x is inconsistent (data: {self.pixels.num_pix_x}, instrument: {num_pix_ra})."
assert self.pixels.num_pix_x == num_pix_ra, error_message_ra
num_pix_dec = round(height / instrument.pixel_size)
error_message_dec = f"Number of pixels along y is inconsistent (data: {self.pixels.num_pix_y}, instrument: {num_pix_dec})."
assert self.pixels.num_pix_y == num_pix_dec, error_message_dec
# TODO: check pixel size value?
# def set_default_field_of_view(self, instrument):
# if not self.pixels.exists:
# return
# pixel_size = self.pixels.pixel_size
# num_pix_x, num_pix_y = self.pixels.shape
# self.field_of_view = ( num_pix_x*pixel_size/2, -num_pix_x*pixel_size/2) # RA is opposite to x
# self.field_of_view_dec = (-num_pix_y*pixel_size/2, num_pix_y*pixel_size/2)
# def _check_images(self):
# self._check_positive(self.wht_map, "WHT map")
# self._check_binary(self.arc_mask, "Arc mask")
# self._check_binary(self.likelihood_mask, "Likelihood mask")
# @staticmethod
# def _check_positive(fits_file, fits_name):
# if not fits_file.exists:
# return
# pixels, _ = fits_file.read()
# if not np.all(pixels > 0):
# raise ValueError(f"{fits_name} pixels should all be positive.")
# @staticmethod
# def _check_binary(fits_file, fits_name):
# if not fits_file.exists:
# return
# pixels, _ = fits_file.read()
# if not np.array_equal(pixels, pixels.astype(bool)):
# raise ValueError(f"{fits_name} pixels should be either 0 or 1.")
