from .AOpticalComponent import AOpticalComponent
from ..IRadiant import IRadiant
from ..SpectralQty import SpectralQty
from ..Entry import Entry
from ...lib.logger import logger
import astropy.units as u
from astropy.io import ascii
from astropy.modeling.models import BlackBody
from typing import Union
import re
import requests as req
import numpy as np
class Atmosphere(AOpticalComponent):
"""
A class to model the atmosphere including the atmosphere's spectral transmittance and emission.
"""
# defining the ATRAN-endpoint
ATRAN = "https://atran.arc.nasa.gov"
def __init__(self, **kwargs):
"""
Initialize a new atmosphere model
Parameters
----------
parent : IRadiant
The parent element of the atmosphere from which the electromagnetic radiation is received.
transmittance : str
Path to the file containing the spectral transmittance-coefficients of the atmosphere.
The format of the file will be guessed by `astropy.io.ascii.read()`.
atran : str
Path to the ATRAN output file containing the spectral transmittance-coefficients of the atmosphere.
altitude : u.Quantity
The observatory altitude in feet.
wl_min : u.Quantity
The minimal wavelength to consider in micrometer.
wl_max : u.Quantity
The maximal wavelength to consider in micrometer.
latitude : u.Quantity
The observatory's latitude in degrees.
water_vapor : u.Quantity
The water vapor overburden in microns (0 if unknown).
n_layers : int
The number of considered atmopsheric layers.
zenith_angle : u.Quantity
The zenith angle of the observation in degrees (0 is towards the zenith).
resolution : int
The resolution for smoothing (0 for no smoothing).
emission : str
Path to the file containing the spectral radiance of the atmosphere.
The format of the file will be guessed by `astropy.io.ascii.read()`.
temp : u.Quantity
The atmospheric temperature for the atmosphere's black body radiation.
"""
args = dict()
if "atran" in kwargs:
args = self._fromATRAN(**{x: kwargs[x] for x in kwargs.keys() if x not in ["emission", "temp"]})
elif "altitude" in kwargs:
logger.info("Requesting ATRAN transmission profile.")
data = self.__call_ATRAN(**{x: kwargs[x] for x in kwargs.keys() if x not in ["parent", "temp"]})
args = self._fromATRAN(parent=kwargs["parent"], atran=data)
elif "transmittance" in kwargs:
args = self._fromFiles(**{x: kwargs[x] for x in kwargs.keys() if x not in ["emission", "temp"]})
else:
logger.error("Wrong parameters for class Atmosphere.")
if "temp" in kwargs:
# Create black body
bb = self.__gb_factory(kwargs["temp"])
# Calculate emission
args["emission"] = SpectralQty(args["transmittance"].wl, bb(args["transmittance"].wl)) * (
-1 * args["transmittance"] + 1)
elif "emission" in kwargs:
args["emission"] = SpectralQty.fromFile(kwargs["emission"], wl_unit_default=u.nm,
qty_unit_default=u.W / (u.m ** 2 * u.nm * u.sr))
super().__init__(parent=args["parent"], transreflectivity=args["transmittance"], noise=args["emission"])
def _fromFiles(self, parent: IRadiant, transmittance: str):
"""
Initialize a new atmosphere model from two files
Parameters
----------
parent : IRadiant
The parent element of the atmosphere from which the electromagnetic radiation is received.
transmittance : str
Path to the file containing the spectral transmittance-coefficients of the atmosphere.
The format of the file will be guessed by `astropy.io.ascii.read()`.
Returns
-------
args : dict
The arguments for the class instantiation.
"""
# Read the transmittance
transmittance = SpectralQty.fromFile(transmittance, wl_unit_default=u.nm,
qty_unit_default=u.dimensionless_unscaled)
return {"parent": parent, "transmittance": transmittance}
def _fromATRAN(self, parent: IRadiant, atran: str):
"""
Initialize a new atmosphere model from an ATRAN output file
Parameters
----------
parent : IRadiant
The parent element of the atmosphere from which the electromagnetic radiation is received.
atran : str
Path to the ATRAN output file containing the spectral transmittance-coefficients of the atmosphere.
Returns
-------
args : dict
The arguments for the class instantiation.
"""
# Read the file
data = self.__parse_ATRAN(atran)
# Create spectral quantity
transmittance = SpectralQty(data["col2"].quantity, data["col3"].quantity)
return {"parent": parent, "transmittance": transmittance}
@u.quantity_input(altitude="length", latitude="angle", water_vapor="length", zenith_angle="angle", wl_min="length",
wl_max="length")
def __call_ATRAN(self, altitude: u.Quantity, wl_min: u.Quantity, wl_max: u.Quantity,
latitude: u.Quantity = 39 * u.degree, water_vapor: u.Quantity = 0 * u.um, n_layers: int = 2,
zenith_angle: u.Quantity = 0 * u.degree, resolution: int = 0):
"""
Call the online version of ATRAN provided by SOFIA
Parameters
----------
altitude : u.Quantity
The observatory altitude in feet.
wl_min : u.Quantity
The minimal wavelength to consider in micrometer.
wl_max : u.Quantity
The maximal wavelength to consider in micrometer.
latitude : u.Quantity
The observatory's latitude in degrees.
water_vapor : u.Quantity
The water vapor overburden in microns (0 if unknown).
n_layers : int
The number of considered atmopsheric layers.
zenith_angle : u.Quantity
The zenith angle of the observation in degrees (0 is towards the zenith).
resolution : int
The resolution for smoothing (0 for no smoothing).
Returns
-------
data : str
The ATRAN computation results
"""
# Select closest latitude from ATRAN options
latitude_ = min(np.array([9, 30, 39, 43, 59]) * u.degree, key=lambda x: abs(x - latitude.to(u.degree)))
# Select closest number of layers from ATRAN options
n_layers_ = min([2, 3, 4, 5], key=lambda x: abs(x - n_layers))
# Assemble the data payload
data = {'Altitude': altitude.to(u.imperial.ft).value,
'Obslat': '%d deg' % latitude_.value,
'WVapor': water_vapor.to(u.um).value,
'NLayers': n_layers_,
'ZenithAngle': zenith_angle.to(u.degree).value,
'WaveMin': wl_min.to(u.um).value,
'WaveMax': wl_max.to(u.um).value,
'Resolution': resolution}
# Send data to ATRAN via POST request
res = req.post(url=self.ATRAN + "/cgi-bin/atran/atran.cgi", data=data)
# Check if request was successful
if not res.ok:
logger.error("Error: Request returned status code " + str(res.status_code))
# Extract the content of the reply
content = res.text
# Check if any ATRAN error occured
match = re.search('ERROR!!
(.*)', content)
if match:
logger.error("Error: " + match.group(1))
# Extract link to ATRAN result file
match = re.search('href="(/atran_calc/atran.(?:plt|smo).\\d*.dat)"', content)
# Check if link was found
if not match:
logger.error("Error: Link to data file not found.")
# Request the ATRAN result via GET request
res = req.get(self.ATRAN + match.group(1))
# Check if request was successful
if not res.ok:
logger.error("Error: Request returned status code " + str(res.status_code))
# Extract the content of the reply
data = res.text
# Check if result is empty
if data == "":
logger.error("Error: Request returned empty response.")
return data
@staticmethod
def __parse_ATRAN(table: str):
"""
Parse an ATRAN result file and convert it to an astropy table
Parameters
----------
table : str
Path to the file or content of the file.
Returns
-------
data : astropy.Table
The parsed table object.
"""
# Read the file
data = ascii.read(table, format=None)
# Set units
data["col2"].unit = u.um
data["col3"].unit = u.dimensionless_unscaled
return data
@staticmethod
@u.quantity_input(temp=[u.Kelvin, u.Celsius])
def __gb_factory(temp: u.Quantity, em: Union[int, float] = 1):
"""
Factory for a grey body lambda-function.
Parameters
----------
temp : Quantity in Kelvin / Celsius
The temperature fo the grey body.
em : Union[int, float]
Emissivity of the the grey body
Returns
-------
bb : Callable
The lambda function for the grey body.
"""
bb = BlackBody(temperature=temp, scale=em * u.W / (u.m ** 2 * u.nm * u.sr))
return lambda wl: bb(wl)
@staticmethod
def check_config(conf: Entry) -> Union[None, str]:
"""
Check the configuration for this class
Parameters
----------
conf : Entry
The configuration entry to be checked.
Returns
-------
mes : Union[None, str]
The error message of the check. This will be None if the check was successful.
"""
if hasattr(conf, "transmittance"):
mes = conf.check_file("transmittance")
if mes is not None:
return mes
elif hasattr(conf, "atran"):
mes = conf.check_file("atran")
if mes is not None:
return mes
else:
mes = conf.check_quantity("altitude", u.imperial.ft)
if mes is not None:
return mes
mes = conf.check_quantity("wl_min", u.um)
if mes is not None:
return mes
mes = conf.check_quantity("wl_max", u.um)
if mes is not None:
return mes
if hasattr(conf, "latitude"):
mes = conf.check_quantity("latitude", u.degree)
if mes is not None:
return mes
if hasattr(conf, "water_vapor"):
mes = conf.check_quantity("water_vapor", u.um)
if mes is not None:
return mes
if hasattr(conf, "n_layers"):
mes = conf.check_float("n_layers")
if mes is not None:
return mes
if hasattr(conf, "zenith_angle"):
mes = conf.check_quantity("zenith_angle", u.degree)
if mes is not None:
return mes
if hasattr(conf, "resolution"):
mes = conf.check_float("resolution")
if mes is not None:
return mes
if hasattr(conf, "emission"):
mes = conf.check_file("emission")
if mes is not None:
return mes
elif hasattr(conf, "temp"):
mes = conf.check_quantity("temp", u.K)
if mes is not None:
return mes