Updated documentation, descriptions for v1.0 release.

scripts/USSA 1976/refraction_height.py

@@ -0,0 +1,91 @@
+#!/usr/bin/env Python3
+import numpy as np
+from pdb import set_trace
+import matplotlib.pyplot as plt
+from matplotlib.lines import Line2D
+import sys
+from AstroAtmosphere import *
+
+'''
+@ Author:		Joost van den Born 
+@ Contact:		born@astron.nl
+@ Description:	We plot the total refraction as a function of height.
+				We find that most refraction happens in the lower atmosphere
+				i.e. <10 km.
+'''
+
+def refractionIntegral2(n, R, z0, n0, R0):
+	z0 = np.deg2rad(z0)
+	return (n0 * R0 * np.sin(z0))/(n*np.sqrt((n*R)**2 - (n0 * R0 * np.sin(z0))**2 ))
+
+def n_for_heights(n0, z0, R0=None, useStandardAtmosphere=True, heightData=None, rhoData=None):
+	'''
+		Using data that gives temperature, pressure and density as a function of height, 
+		the gladstone-dale relation is invoked to calculate the path of a light ray 
+		along the atmosphere. This is allows us to also include atmospheric activity in 
+		different atmosphere layers.
+		Recommended use with the US Standard Atmosphere from 1976.
+		USSA1976 data generated from code supplied by http://www.pdas.com/atmos.html
+	'''
+	if useStandardAtmosphere:
+		_h, _, _, _, _Temp, _Press, _Dens,_,_,_ = np.genfromtxt('si1py_modified.txt', unpack=True, skip_header=6)
+	else:
+		_Dens = rhoData
+		_h 	  = heightData
+	z0 		= np.deg2rad(z0)
+	_Dens 	= np.asarray(_Dens)
+	_h 	 	= np.asarray(_h) 
+	_R 		= R0 + _h * 1000
+	
+	# Gladstone-Dale relation between refractive index and density
+	_n_h = 1 + (n0 - 1) / _Dens[0] * _Dens
+	_z_h = np.arcsin( (n0 * R0) / (_n_h * _R) * np.sin(z0) )
+
+	return _h, _n_h, np.degrees(_z_h)
+
+
+h, _, _, _, Temp, Press, Dens, vSound, _,_ = np.genfromtxt('si1py_modified.txt', unpack=True, skip_header=6)
+
+
+# Conditions
+T   = 288.15 	# k
+P   = 101324  	# Pa
+H   = 0.0
+xc  = 314   	# ppm
+lat = -24.5983 	# degrees
+h0   = 0  	# m
+l1  = 1.49 		# micron
+l2  = 1.78 		# micron
+zenith = 60 	# degrees
+
+# Calculate the index of refraction
+at  = Observatory()
+n1  = at.n_tph(l=l1, T=T, p=P, RH=H, xc=xc)
+n2  = at.n_tph(l=l2, T=T, p=P, RH=H, xc=xc)
+rho = at.rho(p=P, T=T, RH=H, xc=xc)
+
+refr = refraction(lat, h0) 
+refr.setReducedHeight(P, rho)
+disp = dispersion(lat, h0)
+disp.setReducedHeight(P, rho)
+
+
+fig = plt.figure(figsize=(5,4))
+ax = fig.add_subplot(111)
+ax.grid(True, alpha=0.3)
+ax.set_xlabel('Height (km)')
+ax.set_ylabel('Normalized cumulative refraction')
+ax.set_xlim([0, h[-1]])
+
+for z in [30]:
+	refList = []
+	dispList = []
+	for i in range(len(h)):
+		refList.append(refr.refractionIntegral(n1, z, useStandardAtmosphere=False, heightData=h[:i+1], rhoData=Dens[:i+1])*3600)
+		dispList.append(disp.refractionIntegral(n1, n2, z, useStandardAtmosphere=False, heightData=h[:i+1], rhoData=Dens[:i+1])*3.6e6)
+
+	ax.plot(h, np.asarray(refList)/refList[-1], 'k-', label='$\lambda=1.49$ $\mu$m, z=%i$^{\\circ}$' %z)	
+ax.set_ylim([0,1.1])
+
+plt.tight_layout()
+plt.show()