Directory for sub-models

sub-models:

-drag model
-thermal model
-sun position
-atmoshphere model (for development purposes)

models/simple_atmosphere.py

@@ -0,0 +1,28 @@
+from input.natural_constants import *
+import numpy as np
+
+# ATMOSPHERE MODEL:
+
+def T_air(h):
+    if h >= 0 and h <= 11000:
+        res = 288.15 - 0.0065 * h
+        return res
+    elif h > 11000 and h <= 20000:
+        res = 216.65
+        return res
+    elif h >= 20000:
+        res = 216.65 + 0.0010 * (h - 20000)
+        return res
+def p_air(h):
+    if h >= 0 and h <= 11000:
+        res = 101325 * ((288.15 - 0.0065 * h)/288.15) ** 5.25577
+        return res
+    elif h > 11000 and h <= 20000:
+        res = 22632 * np.exp(-(h - 11000)/6341.62)
+        return res
+    elif h > 20000:
+        res = 5474.87 * ((216.65 + 0.0010 * (h - 20000))/216.65) ** (-34.163)
+        return res
+def rho_air(h):
+    res = p_air(h)/(R_air * T_air(h))
+    return res