From a531f0a26b20d4ad446457b6b8c8c28c2640f9b0 Mon Sep 17 00:00:00 2001
From: LukasK13 <spam.lukas.klass@gmail.com>
Date: Wed, 8 Apr 2020 09:56:04 +0200
Subject: [PATCH] Target added

---
 esbo_etc/classes/target/ATarget.py         | 44 +++++++++++++++++++
 esbo_etc/classes/target/BlackBodyTarget.py | 50 ++++++++++++++++++++++
 esbo_etc/classes/target/__init__.py        |  2 +
 3 files changed, 96 insertions(+)
 create mode 100644 esbo_etc/classes/target/ATarget.py
 create mode 100644 esbo_etc/classes/target/BlackBodyTarget.py
 create mode 100644 esbo_etc/classes/target/__init__.py

diff --git a/esbo_etc/classes/target/ATarget.py b/esbo_etc/classes/target/ATarget.py
new file mode 100644
index 0000000..ca6ccb7
--- /dev/null
+++ b/esbo_etc/classes/target/ATarget.py
@@ -0,0 +1,44 @@
+from abc import abstractmethod
+from ..ITransmissive import ITransmissive
+from ..SpectralQty import SpectralQty
+
+
+class ATarget(ITransmissive):
+    """
+    Abstract super class for target models
+    """
+    @abstractmethod
+    def __init__(self, sfd: SpectralQty):
+        """
+        Initialize a new target
+
+        Parameters
+        ----------
+        sfd: SpectralQty
+            The spectral flux density of the target
+        """
+        self._sfd = sfd
+
+    @abstractmethod
+    def calcNoise(self) -> SpectralQty:
+        """
+        Calculate the spectral radiance of the target's noise
+
+        Returns
+        -------
+        noise : SpectralQty
+            The spectral radiance of the target's noise
+        """
+        return SpectralQty(self.sfd.wl, [0] * len(self.sfd.wl))
+
+    def calcSignal(self) -> SpectralQty:
+        """
+        Calculate the spectral flux density of the target's signal
+
+        Returns
+        -------
+        signal : SpectralQty
+            The spectral flux density of the target's signal
+        """
+        return self.sfd
+
diff --git a/esbo_etc/classes/target/BlackBodyTarget.py b/esbo_etc/classes/target/BlackBodyTarget.py
new file mode 100644
index 0000000..35646ed
--- /dev/null
+++ b/esbo_etc/classes/target/BlackBodyTarget.py
@@ -0,0 +1,50 @@
+from ..target.ATarget import ATarget
+from ..SpectralQty import SpectralQty
+import astropy.units as u
+from astropy.modeling.models import BlackBody
+from esbo_etc.lib.helpers import error
+
+
+class BlackBodyTarget(ATarget):
+    """
+    This class models the spectral flux density of a star of given magnitude using as black body radiator
+    """
+    # Bands from Handbook of Space Astronomy and Astrophysics
+    # band_sfd = {"U": 1790*u.Jansky, "B": 4063*u.Jansky, "V": 3636*u.Jansky, "R": 3064*u.Jansky,
+    #            "I": 2416*u.Jansky, "J": 1590*u.Jansky, "H": 1020*u.Jansky, "K": 640*u.Jansky}
+    band_sfd = {"U": 4.175e-11, "B": 6.32e-11, "V": 3.631e-11, "R": 2.177e-11,
+                "I": 1.126e-11, "J": 3.15e-12, "H": 1.14e-12, "K": 3.96e-13}
+    band_sfd = {k: v * u.W / (u.m ** 2 * u.nm) for k, v in band_sfd.items()}
+    band_wl = {"U": 366 * u.nanometer, "B": 438 * u.nanometer, "V": 545 * u.nanometer, "R": 641 * u.nanometer,
+               "I": 798 * u.nanometer, "J": 1220 * u.nanometer, "H": 1630 * u.nanometer, "K": 2190 * u.nanometer}
+
+    @u.quantity_input(wl_bins='length', temp=[u.Kelvin, u.Celsius], mag=u.mag)
+    def __init__(self, wl_bins: u.Quantity, temp: u.Quantity = 5778 * u.K,
+                 mag: u.Quantity = 0 * u.mag, band: str = "V"):
+        """
+        Initialize a new black body point source
+
+        Parameters
+        ----------
+        wl_bins : length-Quantity
+            Wavelengths used for binning
+        temp : Quantity in Kelvin / Celsius
+            Temperature of the black body
+        mag : Quantity in mag
+            Desired apparent magnitude of the point source
+        band : str
+            Band used for fitting the planck curve to a star of 0th magnitude
+        """
+        if band not in self.band_wl.keys():
+            error("Band has to be one of '[" + ", ".join(list(self.band_wl.keys())) + "]'")
+        # Create blackbody model with given temperature
+        bb = BlackBody(temperature=temp, scale=1 * u.W / (u.m ** 2 * u.nm * u.sr))
+
+        # Calculate the correction factor for a star of 0th magnitude using the spectral flux density
+        # for the central wavelength of the given band
+        factor = self.band_sfd[band] / (bb(self.band_wl[band]) * u.sr)
+        # Calculate spectral flux density for the given wavelengths and scale it for a star of the given magnitude
+        sfd = bb(wl_bins) * factor * 10 ** (- 2 / 5 * mag / u.mag)
+
+        # Initialize super class
+        super().__init__(SpectralQty(self.band_wl, sfd))
diff --git a/esbo_etc/classes/target/__init__.py b/esbo_etc/classes/target/__init__.py
new file mode 100644
index 0000000..0b4b467
--- /dev/null
+++ b/esbo_etc/classes/target/__init__.py
@@ -0,0 +1,2 @@
+from esbo_etc.classes.target.ATarget import *
+from esbo_etc.classes.target.BlackBodyTarget import *