#! /usr/bin/env python3
#
# Copyright 2018 California Institute of Technology
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
# ISOFIT: Imaging Spectrometer Optimal FITting
# Author: David R Thompson, david.r.thompson@jpl.nasa.gov
#
import numpy as np
import scipy.linalg
from isofit.configs import Config
from ..core.common import emissive_radiance, eps
from .surface_multicomp import MultiComponentSurface
[docs]
class ThermalSurface(MultiComponentSurface):
"""A model of the surface based on a Mixture of a hot Black Body and
Multicomponent cold surfaces."""
def __init__(self, full_config: Config):
"""."""
config = full_config.forward_model.surface
super().__init__(full_config)
# TODO: Enforce this attribute in the config, not here (this is hidden)
# Handle additional state vector elements
if "SURF_TEMP_K" not in self.statevec_names:
self.statevec_names.extend(["SURF_TEMP_K"])
self.init.extend([300.0]) # This is overwritten below
self.scale.extend([100.0])
self.bounds.extend([[250.0, 400.0]])
self.surf_temp_ind = len(self.statevec_names) - 1
self.emissive = True
self.n_state = len(self.init)
self.emissivity_for_surface_T_init = config.emissivity_for_surface_T_init
self.surface_T_prior_sigma_degK = config.surface_T_prior_sigma_degK
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def xa(self, x_surface, geom):
"""Mean of prior distribution, calculated at state x. We find
the covariance in a normalized space (normalizing by z) and then un-
normalize the result for the calling function."""
mu = MultiComponentSurface.xa(self, x_surface, geom)
mu[self.surf_temp_ind] = self.init[self.surf_temp_ind]
return mu
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def Sa(self, x_surface, geom):
"""Covariance of prior distribution, calculated at state x."""
Cov = MultiComponentSurface.Sa(self, x_surface, geom)
Cov[self.surf_temp_ind, self.surf_temp_ind] = self.surface_T_prior_sigma_degK**2
return Cov
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def fit_params(self, rfl_meas, geom, *args):
"""Given a reflectance estimate, find the surface reflectance"""
x_surface = MultiComponentSurface.fit_params(self, rfl_meas, geom)
x_surface[self.surf_temp_ind] = self.init[self.surf_temp_ind]
return x_surface
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def calc_rfl(self, x_surface, geom):
"""Reflectance. This could be overriden to add (for example)
specular components"""
return self.calc_lamb(x_surface, geom)
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def drfl_dsurface(self, x_surface, geom):
"""Partial derivative of reflectance with respect to state vector,
calculated at x_surface."""
return self.dlamb_dsurface(x_surface, geom)
[docs]
def calc_lamb(self, x_surface, geom):
"""Lambertian Reflectance."""
return MultiComponentSurface.calc_lamb(self, x_surface, geom)
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def dlamb_dsurface(self, x_surface, geom):
"""Partial derivative of Lambertian reflectance with respect to state
vector, calculated at x_surface."""
dlamb = MultiComponentSurface.dlamb_dsurface(self, x_surface, geom)
dlamb[:, self.surf_temp_ind] = 0
return dlamb
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def calc_Ls(self, x_surface, geom):
"""Emission of surface, as a radiance."""
T = x_surface[self.surf_temp_ind]
rfl = self.calc_rfl(x_surface, geom)
rfl[rfl > 1.0] = 1.0
emissivity = 1 - rfl
Ls, dLs_dT = emissive_radiance(emissivity, T, self.wl)
return Ls
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def dLs_dsurface(self, x_surface, geom):
"""Partial derivative of surface emission with respect to state vector,
calculated at x_surface."""
T = x_surface[self.surf_temp_ind]
lambertian_rfl = self.calc_lamb(x_surface, geom)
emissivity = 1 - lambertian_rfl
Ls, dLs_dT = emissive_radiance(emissivity, T, self.wl)
dLs_drfl = np.diag(-1 * Ls)
dLs_dsurface = np.vstack([dLs_drfl, dLs_dT]).T
return dLs_dsurface
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def summarize(self, x_surface, geom):
"""Summary of state vector."""
mcm = MultiComponentSurface.summarize(self, x_surface, geom)
msg = " Kelvins: %5.1f " % x_surface[self.surf_temp_ind]
return msg + mcm