128 lines
4.8 KiB
Python
128 lines
4.8 KiB
Python
from .AOpticalComponent import AOpticalComponent
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from ..IRadiant import IRadiant
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from ..SpectralQty import SpectralQty
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from ..Entry import Entry
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from ...lib.logger import logger
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import astropy.units as u
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from astropy.io import ascii
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from astropy.modeling.models import BlackBody
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from typing import Union
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class Atmosphere(AOpticalComponent):
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"""
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A class to model the atmosphere including the atmosphere's spectral transmittance and emission.
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"""
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def __init__(self, **kwargs):
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"""
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Initialize a new atmosphere model
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Parameters
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----------
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parent : IRadiant
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The parent element of the atmosphere from which the electromagnetic radiation is received.
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This element is usually of type Target or StrayLight.
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transmittance : str
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Path to the file containing the spectral transmittance-coefficients of the atmosphere.
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The format of the file will be guessed by `astropy.io.ascii.read()`.
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emission : str
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Path to the file containing the spectral radiance of the atmosphere.
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The format of the file will be guessed by `astropy.io.ascii.read()`.
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"""
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args = dict()
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if "temp" in kwargs:
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args = self._fromATRAN(**kwargs)
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elif "transmittance" in kwargs:
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args = self._fromFiles(**kwargs)
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else:
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logger.error("Wrong parameters for class Atmosphere.")
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super().__init__(parent=args["parent"], transreflectivity=args["transmittance"], noise=args["emission"])
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def _fromFiles(self, parent: IRadiant, transmittance: str, emission: str = None):
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"""
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Initialize a new atmosphere model from two files
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Parameters
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----------
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parent : IRadiant
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The parent element of the atmosphere from which the electromagnetic radiation is received.
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This element is usually of type Target or StrayLight.
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transmittance : str
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Path to the file containing the spectral transmittance-coefficients of the atmosphere.
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The format of the file will be guessed by `astropy.io.ascii.read()`.
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emission : str
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Path to the file containing the spectral radiance of the atmosphere.
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The format of the file will be guessed by `astropy.io.ascii.read()`.
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"""
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# Read the transmittance
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transmittance = SpectralQty.fromFile(transmittance, wl_unit_default=u.nm,
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qty_unit_default=u.dimensionless_unscaled)
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if emission is None:
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emission = 0
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else:
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emission = SpectralQty.fromFile(emission, wl_unit_default=u.nm,
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qty_unit_default=u.W / (u.m ** 2 * u.nm * u.sr))
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return {"parent": parent, "transmittance": transmittance, "emission": emission}
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def _fromATRAN(self, parent: IRadiant, transmittance: str, temp: u.Quantity):
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transmittance = "data_sofia/atmospheric_transmittance.dat"
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# Read the file
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data = ascii.read(transmittance, format=None)
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# Set units
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data["col2"].unit = u.um
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data["col3"].unit = u.dimensionless_unscaled
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# Create spectral quantity
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transmittance = SpectralQty(data["col2"].quantity, data["col3"].quantity)
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# Create black body
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bb = self.__gb_factory(temp)
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# Calculate emission
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emission = SpectralQty(transmittance.wl, bb(transmittance.wl)) * transmittance
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return {"parent": parent, "transmittance": transmittance, "emission": emission}
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@staticmethod
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def check_config(conf: Entry) -> Union[None, str]:
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"""
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Check the configuration for this class
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Parameters
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----------
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conf : Entry
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The configuration entry to be checked.
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Returns
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-------
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mes : Union[None, str]
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The error message of the check. This will be None if the check was successful.
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"""
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mes = conf.check_file("transmittance")
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if mes is not None:
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return mes
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if hasattr(conf, "emission"):
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mes = conf.check_file("emission")
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if mes is not None:
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return mes
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@staticmethod
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@u.quantity_input(temp=[u.Kelvin, u.Celsius])
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def __gb_factory(temp: u.Quantity, em: Union[int, float] = 1):
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"""
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Factory for a grey body lambda-function.
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Parameters
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----------
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temp : Quantity in Kelvin / Celsius
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The temperature fo the grey body.
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em : Union[int, float]
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Emissivity of the the grey body
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Returns
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-------
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bb : Callable
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The lambda function for the grey body.
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"""
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bb = BlackBody(temperature=temp, scale=em * u.W / (u.m ** 2 * u.nm * u.sr))
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return lambda wl: bb(wl)
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