Files
AtmosphericModel/scripts/compare_models_with_SLALIB.py

248 lines
10 KiB
Python

#!/usr/bin/env Python
import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits.axes_grid1 import host_subplot
from AstroAtmosphere import *
from pyslalib import slalib
'''
@ Author: Joost van den Born
@ Contact: born@astron.nl
@ Description: This script was used to compare the impact of using the old
B&S equations, and the particular implementation of SLALIB.
The rest of the script is almost a one-to-one copy of other
script that compared the atmospheric models.
Modeling the atmospheric refraction using multiple models of
the atmosphere and then comparing them.
Models included:
- Full integration method
- Plane-parallel atmosphere
- Cassini's model
- Tan5 model (A*tan(z) + B*tan^3(z) + C*tan^5(z))
- Oriani's theorem (A*tan(z) + B*tan^3(z))
- Erf model (from Corbard et al., 2019)
- SLALIB
'''
class atmosphereSLALIB:
def __init__(self, T=279.65, P=712, H=0.22):
self.name = 'SLALIB atmosphere'
self.T = T
self.P = P
self.H = H
self.h = 3064
self.lat = -24.5983
self.TLR = 0.0065
self.prec = 1e-8
def atmModel(self, A, B, zenith):
zenith = np.radians(zenith)
return A * np.tan(zenith) + B * (np.tan(zenith)**3)
def dispersion(self, l1, l2, z):
A1, B1 = slalib.sla_refco(self.h, self.T, self.P, self.H, l1, np.deg2rad(self.lat), self.TLR, self.prec)
A2, B2 = slalib.sla_atmdsp(self.T, self.P, self.H, l1, A1, B1, l2)
D1 = np.degrees(self.atmModel(A1, B1, z)) * 3600
D2 = np.degrees(self.atmModel(A2, B2, z)) * 3600
dispersionValue = ((D1 - D2) * 1000)
return dispersionValue
def refractivity(self, l=None):
'''
SLALIB uses the same atmospheric model as ZEMAX
based on the works of Hohenkerk & Sinclair and Seidelmann.
They take the B&S refraction formula as a basis.
'''
zObs = np.deg2rad(45.06563)
h = 0
T = self.T
P = self.P
H = self.H
lat = 24
tlr = 0.0065
eps = 1e-10
if not l:
l = self.lrange
R = []
if type(l) == float:
l = [l]
for wl in l:
R.append(slalib.sla_refro(zObs, h, T, P, H, wl, lat, tlr, eps)+1)
return np.asarray(R)
if __name__ == '__main__':
plt.rc('font', family='serif')
# plt.rc('xtick', labelsize='x-small')
# plt.rc('ytick', labelsize='x-small')
plt.rc('axes', labelsize='large')
# Standard atmospheric conditions
# T = 279.65 # k
# P = 71200 # Pa
# H = 0.22
# xc = 450 # ppm
T = 288.15 # k
P = 101325 # Pa
H = 0.0
xc = 314 # ppm
lat = -24.5983 # degrees
h = 3064 # m
l1 = 1.49 # micron
l2 = 1.78 # micron
zenith = 30 # 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)
#######################################################
# DIRECT COMPARISON
ref = dispersion(lat, h)
ref.setReducedHeight(P, rho)
print('Ciddor refractivity: ', n1, n2)
print ('Cassini dispersion: %s mas' %(ref.cassini(n1, n2, zenith) * 3.6e6))
n1c = n1
n2c = n2
refraction = refraction(lat, h)
refraction.setReducedHeight(P, rho)
refractionValueCiddor = refraction.cassini(n1c, zenith) * 3.6e6 # in mas
# SLALIB
atSLALIB = atmosphereSLALIB(T, P/100, H)
n1 = atSLALIB.refractivity(l1)
n2 = atSLALIB.refractivity(l2)
print('B&S refractivity: ', n1, n2)
print ('SLALIB model: %s mas' %(atSLALIB.dispersion(l1, l2, zenith) ) )
# SLALIB refraction:
A1, B1 = slalib.sla_refco(atSLALIB.h, atSLALIB.T, atSLALIB.P, atSLALIB.H, l1, np.deg2rad(atSLALIB.lat), atSLALIB.TLR, atSLALIB.prec)
refractionValueSLALIB = np.degrees(atSLALIB.atmModel(A1, B1, zenith)) * 3.6e6 # in mas
print('Differential dispersion = {} mas'.format(atSLALIB.dispersion(l1, l2, zenith) - ref.cassini(n1c, n2c, zenith) * 3.6e6) )
print('Differential refraction = {} mas'.format( refractionValueSLALIB - refractionValueCiddor ) )
#######################################################
refractionAnalysis = True
dispersionAnalysis = True
tableCompare = True
if dispersionAnalysis:
# Initiate the refraction class
ref = dispersion(lat, h)
ref.setReducedHeight(P, rho)
# Compare the refraction models to check if the output is okay
print ('Plane - parallel atmosphere dispersion: %s mas' %(ref.planeParallel(n1, n2, zenith) * 3.6e6))
print ('Cassini dispersion: %s mas' %(ref.cassini(n1, n2, zenith) * 3.6e6))
print ('Tan5 dispersion: %s mas' %(ref.tan5(n1, n2, zenith) * 3.6e6))
print ('Oriani dispersion: %s mas' %(ref.oriani(n1, n2, zenith) * 3.6e6))
print ('Corbard dispersion: %s mas' %(ref.corbard(n1, n2, zenith)*3.6e6))
print ('Full integration: %s mas' %(ref.refractionIntegral(n1, n2, zenith)*3.6e6))
print ('SLALIB model: %s mas' %(atSLALIB.dispersion(l1, l2, zenith) ) )
# Now we calculate the dispersion over a wide range of zenith angles
# for ideal gas atmosphere
zenithRange = np.linspace(30, 85, 1000)
ppList = ref.planeParallel(n1, n2, zenithRange) * 3.6e6
cassiniList = ref.cassini(n1, n2, zenithRange) * 3.6e6
tan5List = ref.tan5(n1, n2, zenithRange) * 3.6e6
orianiList = ref.oriani(n1, n2, zenithRange) * 3.6e6
corbardList = [ref.corbard(n1, n2, z)[0] * 3.6e6 for z in zenithRange]
fullIntegrationList = np.asarray([ref.refractionIntegral(n1, n2, z) * 3.6e6 for z in zenithRange])
slalibList = atSLALIB.dispersion(l1, l2, zenithRange)
# for isothermal atmosphere
cassiniList_isotherm = ref.cassini(n1, n2, zenithRange, reduced_height=ref.H_isotherm(T)) * 3.6e6
tan5List_isotherm = ref.tan5(n1, n2, zenithRange, reduced_height=ref.H_isotherm(T)) * 3.6e6
orianiList_isotherm = ref.oriani(n1, n2, zenithRange, reduced_height=ref.H_isotherm(T)) * 3.6e6
corbardList_isotherm = [ref.corbard(n1, n2, z, reduced_height=ref.H_isotherm(T))[0] * 3.6e6 for z in zenithRange]
# check when the variation between the different models pass different values
dispersionWidth = []
widthList = []
for z in range(len(zenithRange)):
compList = [cassiniList[z], tan5List[z], orianiList[z], corbardList[z], cassiniList_isotherm[z], tan5List_isotherm[z], orianiList_isotherm[z], corbardList_isotherm[z], slalibList[z]]#, fullIntegrationList[z]]
width = np.max(compList) - np.min(compList)
widthList.append(width)
dispersionWidth.append((zenithRange[z], width))
masBorder = np.argmax(np.asarray(widthList)>1)
p1masBorder = np.argmax(np.asarray(widthList)>0.1)
p01masBorder = np.argmax(np.asarray(widthList)>0.01)
p001masBorder = np.argmax(np.asarray(widthList)>0.001)
plotAbsolute = 1
if plotAbsolute:
# Plotting it all, with vertical lines where the variation between the models exceed 1, 0.1, 0.01 and 0.001 mas.
fig = plt.figure(figsize=(9,5))
ax = fig.add_subplot(111)
ax.set_xlim([30,85])
ax.set_xlabel('Zenith (degrees)')
ax.set_ylabel('Dispersion (mas)')
ax.grid(True, alpha=0.3)
ax.axvline(dispersionWidth[masBorder][0], linestyle='--', color='k', linewidth=0.5)
ax.text(dispersionWidth[masBorder][0]-0.5, 402, '1 mas', ha='center', va='bottom', rotation='vertical')
ax.axvline(dispersionWidth[p1masBorder][0], linestyle='--', color='k', linewidth=0.5)
ax.text(dispersionWidth[p1masBorder][0]-0.5, 402, '0.1 mas', ha='center', va='bottom', rotation='vertical')
ax.axvline(dispersionWidth[p01masBorder][0], linestyle='--', color='k', linewidth=0.5)
ax.text(dispersionWidth[p01masBorder][0]-0.5, 402, '10 $\mu$as', ha='center', va='bottom', rotation='vertical')
ax.axvline(dispersionWidth[p001masBorder][0], linestyle='--', color='k', linewidth=0.5)
ax.text(dispersionWidth[p001masBorder][0]-0.5, 402, '1 $\mu$as', ha='center', va='bottom', rotation='vertical')
ax.plot(zenithRange, ppList, 'k-', label='Plane-parallel', alpha=0.2)
ax.plot(zenithRange, cassiniList, 'g-', label='Cassini')
ax.plot(zenithRange, tan5List, 'b-', label='$Atan(z) - Btan^3(z) + Ctan^5(z)$')
ax.plot(zenithRange, orianiList, 'y-', label='$Atan(z) - Btan^3(z)$')
ax.plot(zenithRange, corbardList, 'r-', label='Error function')
ax.plot(zenithRange, fullIntegrationList, 'c-', label='Full integration')
ax.plot(zenithRange, cassiniList_isotherm, 'g--', label='Cassini (isotherm)')
ax.plot(zenithRange, tan5List_isotherm, 'b--', label='$Atan(z) - Btan^3(z) + Ctan^5(z)$ (isotherm)')
ax.plot(zenithRange, orianiList_isotherm, 'y--', label='$Atan(z) - Btan^3(z)$ (isotherm)')
ax.plot(zenithRange, corbardList_isotherm, 'r--', label='Error function (isotherm)')
ax.tick_params(axis ='both', direction='in')
ax.legend()
plt.tight_layout()
plt.show()
plotRelative = 1
if plotRelative:
# RELATIVE TO FULL INTEGRATION
fig = plt.figure(figsize=(9,6))
ax = fig.add_subplot(111)
ax.set_xlim([30,85])
ax.set_xlabel('Zenith (degrees)', fontsize=18)
ax.set_ylabel(r'$\log_{10}(|(\Delta R - \Delta R_{int})|$ mas$^{-1})$', fontsize=18)
ax.axhline(np.log10(0.4), linestyle='-', linewidth=1, color='red')
ax.text(30.5, np.log10(0.4)+0.05, 'Residual dispersion requirement', fontsize=12)
ax.grid(True, which='major', alpha=0.3)
ax.grid(True, which='minor', alpha=0.2)
ax.plot(zenithRange, np.log10(np.abs(ppList-fullIntegrationList)), color='k', linestyle='-', linewidth=2, label='Plane-parallel')
ax.plot(zenithRange, np.log10(np.abs(cassiniList-fullIntegrationList)), color='g', linestyle=(0, (1, 1)), linewidth=2, label='Cassini')
ax.plot(zenithRange, np.log10(np.abs(orianiList-fullIntegrationList)), color='y', linestyle='-.', linewidth=2, label='Oriani')
ax.plot(zenithRange, np.log10(np.abs(tan5List-fullIntegrationList)), color='b', linestyle=(0, (5, 1)), linewidth=2, label='Oriani incl. fifth order')
ax.plot(zenithRange, np.log10(np.abs(np.asarray(corbardList)-fullIntegrationList)), color='r', linestyle=(0, (3, 1, 1, 1, 1, 1)), linewidth=2, label='Error function')
ax.plot(zenithRange, np.log10(np.abs(np.asarray(slalibList)-fullIntegrationList)), color='m', linewidth=2, label='SLALIB')
ax.plot(zenithRange, np.log10(np.abs(cassiniList-fullIntegrationList)), color='g', linestyle=(0, (1, 1)), linewidth=2)
ax.set_ylim(top=2.6, bottom=-7.2)
ax.tick_params(axis ='both', direction='in', labelsize=16)
ax.legend(fontsize=14, labelspacing=0.3, columnspacing=0.5, handletextpad=0.3, ncol=1, loc='lower right')
plt.tight_layout()
plt.show()