"""
compare own results against references
from the Ulaby example codes provided
http://mrs.eecs.umich.edu/codes/Module10_5/Module10_5.html
for the Oh92 model (PRISM1)
"""
import sys
import os
sys.path.append(os.path.abspath(os.path.dirname(__file__)) + os.sep + '..')
from sense.surface import Oh92
from sense.util import f2lam
import matplotlib.pyplot as plt
import numpy as np
plt.close('all')
eps = 30.8 - 40.j # note that normally the imagionary part is supposed to be negative!
freq = 1. # GH
s = 0.05 # m
ks = (2. * np.pi / f2lam(freq)) * s
theta = np.deg2rad(np.arange(0., 70.))
O = Oh92(eps, ks, theta)
O.plot()
plt.show()
from sense.util import f2lam
from sense.model import RTModel
from sense.soil import Soil
from sense.canopy import OneLayer
import matplotlib.pyplot as plt
import pdb
plt.close('all')
theta_deg = np.arange(0., 70.)
# theta_deg = 40.
theta = np.deg2rad(theta_deg)
f = 13. # GHz
lam = f2lam(f) # m
s = 0.0015 # m
l = 0.015 # m
omega = 0.1
#guessed from figure in chapter 4 for the time being
eps = 15. - 4.0j
models = {'surface': 'Oh92', 'canopy': 'turbid_rayleigh'}
pol = 'vv'
# short alfalfa
d = 0.17
def test_scat_rayleigh(self):
theta = self.theta*1.
#theta = np.array([np.deg2rad(90.)])
stype = 'turbid_rayleigh'
models = {'surface': 'Oh92', 'canopy': stype}
eps = 15. -3.j
d = 2.
ke = 0.05
omega=0.5
soil = Soil(eps=eps, f=5., s=0.02)
can = OneLayer(ke_h=ke, ke_v=ke, d=d, ks_h = omega*ke, ks_v = omega*ke)
S = model.SingleScatRT(surface=soil, canopy=can, models=models, theta=theta, freq=self.freq)
S.sigma0()
models = {'surface': 'Dubois95', 'canopy': stype}
S = model.SingleScatRT(surface=soil, canopy=can, models=models, theta=theta, freq=self.freq)
S.sigma0()
# compare results against results obtained through Eq. 11.23 (analytic way)
SMODEL = Dubois95(eps, soil.ks, theta, lam=f2lam(soil.f))
s_hh_surf = SMODEL.hh
s_vv_surf = SMODEL.vv
trans = np.exp(-d*ke/np.cos(theta))
n=2. # 2== coherent
RHO_h = S.G.rho_h
RHO_v = S.G.rho_v
ref_hh = trans**2. * s_hh_surf + (0.75*omega)*np.cos(theta)*(1.-trans**2.)*(1.+RHO_h**2.*trans**2.)+3.*n*omega*ke*d*RHO_h*trans**2.
ref_vv = trans**2. * s_vv_surf + (0.75*omega)*np.cos(theta)*(1.-trans**2.)*(1.+RHO_v**2.*trans**2.)+3.*n*omega*ke*d*RHO_v*trans**2.
pol = 'hh'
self.assertEqual(len(ref_hh), len(S.stot[pol]))
for i in xrange(len(ref_hh)):
#print np.rad2deg(theta[i]), ref_hh[i]
if np.isnan(ref_hh[i]):
self.assertTrue(np.isnan(S.stot[pol][i]))
else:
# check components first
self.assertAlmostEqual(S.s0g[pol][i], s_hh_surf[i]*trans[i]**2.) # attenuated ground
self.assertAlmostEqual(S.s0c[pol][i]+S.s0gcg[pol][i], 0.75*omega*np.cos(theta[i])*(1.-trans[i]**2.)*(1.+RHO_h[i]**2.*trans[i]**2.))
# gcg
xx=3.*n*omega*ke*d*RHO_h[i]*trans[i]**2.
print np.rad2deg(theta[i]), S.s0gcg[pol][i],xx, S.s0gcg[pol][i]/xx
self.assertAlmostEqual(S.s0cgt[pol][i],xx)
db1=db(ref_hh[i])
db2=db(S.stot[pol][i])
self.assertAlmostEqual(db1,db2)
pol = 'vv'
self.assertEqual(len(ref_vv), len(S.stot[pol]))
for i in xrange(len(ref_vv)):
#print theta[i], ref_vv[i]
if np.isnan(ref_vv[i]):
self.assertTrue(np.isnan(S.stot[pol][i]))
else:
self.assertAlmostEqual(db(ref_vv[i]), db(S.stot[pol][i]))