def test_HenyeyGreenstein(self):
V = HenyeyGreenstein(omega=0.2, tau=1.7, t=0.7, ncoefs=20)
self.assertEqual(V.t, 0.7)
t_0 = np.pi / 2.
t_ex = 0.234234
p_0 = np.pi / 2.
p_ex = 0.
#--> cos(THETA) = 0
p = V.p(t_0, t_ex, p_0, p_ex)
self.assertAlmostEqual(p, (1. - 0.7 * 0.7) /
(4. * np.pi * (1. + 0.7 * 0.7)**1.5), 10)
def set_V_SRF(frac, omega, SM, VOD, v, v2, **kwargs):
SRFchoices = [[frac, HG_nadirnorm(t=0.01, ncoefs=2, a=[-1., 1., 1.])],
[(1. - frac),
HG_nadirnorm(t=0.6, ncoefs=10, a=[1., 1., 1.])]]
SRF = LinCombSRF(SRFchoices=SRFchoices, NormBRDF=SM)
V = HenyeyGreenstein(t=v, omega=omega, tau=v2 * VOD, ncoefs=8)
return V, SRF
def test_fn_coefficients_HGIso(self):
# test if calculation of fn coefficients is correct
# this is done by comparing the obtained coefficients
# against the analytical solution using a Rayleigh volume
# and isotropic surface scattering phase function
S = Isotropic()
t_0 = 0.
t_ex = 0.
p_0 = 0.
p_ex = np.pi
V = HenyeyGreenstein(omega=0.2, tau=1.7, t=0.7, ncoefs=1)
RT = RT1(self.I0, t_0, t_ex, p_0, p_ex, V=V, SRF=S, geometry='ffff')
r = RT._fnevals(t_0, p_0, t_ex, p_ex)
self.assertTrue(np.allclose(r[0], 1. / (2. * np.pi)))
def test_example_2_int(self):
print('Testing Example 2 ...')
inc = self.inc2
# ---- evaluation of second example
V = HenyeyGreenstein(tau=0.7, omega=0.3, t=0.7, ncoefs=20)
SRF = CosineLobe(ncoefs=10, i=5, NormBRDF=np.pi)
R = RT1(1.,
np.deg2rad(inc),
np.deg2rad(inc),
np.zeros_like(inc),
np.full_like(inc, np.pi),
V=V,
SRF=SRF,
geometry='mono')
self.assertTrue(np.allclose(self.int_num_2, R.calc()[3], atol=1e-6))
example = 3
# ----------- definition of examples -----------
if example == 1:
# define incidence-angle range for generation of backscatter-plots
inc = np.arange(1., 89., 1.)
# Example 1
V = Rayleigh(tau=0.55, omega=0.24)
SRF = CosineLobe(ncoefs=15, i=6, a=[.28, 1., 1.])
label = 'Example 1'
elif example == 2:
# define incidence-angle range for generation of backscatter-plots
inc = np.arange(1., 89., 1.)
V = HenyeyGreenstein(tau=0.7, omega=0.3, t=0.7, ncoefs=20)
SRF = CosineLobe(ncoefs=10, i=5)
label = 'Example 2'
elif example == 3:
# define incidence-angle range for generation of backscatter-plots
inc = np.arange(1., 89., 1.)
# list of volume-scattering phase-functions to be combined
phasechoices = [
# forward-scattering-peak
HenyeyGreenstein(t=0.5, ncoefs=10, a=[-1., 1., 1.]),
# backscattering-peak
HenyeyGreenstein(t=-0.2, ncoefs=10, a=[-1., 1., 1.]),
# downward-specular peak
HenyeyGreenstein(t=-0.5, ncoefs=10, a=[1., 1., 1.]),
# upward-specular peak
HenyeyGreenstein(t=0.2, ncoefs=10, a=[1., 1., 1.]),
def test_HenyeyGreenstein_coefficients(self):
V = HenyeyGreenstein(omega=0.2, tau=1.7, t=0.7, ncoefs=20)
self.assertEqual(V._get_legcoef(0), 1. / (4. * np.pi))
self.assertEqual(V._get_legcoef(1), 3. * 0.7 / (4. * np.pi))