def getSystemT(newLambda, bg3fn: Path, windfn: Path, qefn: Path,
obsalt_km, zenang_deg, verbose: bool = False) -> xarray.Dataset:
bg3fn = Path(bg3fn).expanduser()
windfn = Path(windfn).expanduser()
qefn = Path(qefn).expanduser()
newLambda = np.asarray(newLambda)
# %% atmospheric absorption
if lowtran is not None:
c1 = {'model': 5, 'h1': obsalt_km, 'angle': zenang_deg,
'wlshort': newLambda[0], 'wllong': newLambda[-1]}
if verbose:
print('loading LOWTRAN7 atmosphere model...')
atmT = lowtran.transmittance(c1)['transmission'].squeeze()
try:
atmTcleaned = atmT.values.squeeze()
atmTcleaned[atmTcleaned == 0] = np.spacing(1) # to avoid log10(0)
fwl = interp1d(atmT.wavelength_nm, np.log(atmTcleaned), axis=0)
except AttributeError: # problem with lowtran
fwl = interp1d(newLambda, np.log(np.ones_like(newLambda)), kind='linear')
else:
fwl = interp1d(newLambda, np.log(np.ones_like(newLambda)), kind='linear')
atmTinterp = np.exp(fwl(newLambda))
if not np.isfinite(atmTinterp).all():
logging.error('problem in computing LOWTRAN atmospheric attenuation, results are suspect!')
# %% BG3 filter
with h5py.File(bg3fn, 'r') as f:
try:
assert isinstance(f['/T'], h5py.Dataset), 'we only allow one transmission curve per file' # simple legacy behavior
fbg3 = interp1d(f['/wavelength'], np.log(f['/T']), kind='linear', bounds_error=False)
except KeyError:
raise KeyError('could not find /wavelength in {}'.format(f.filename))
try:
fname = f['T'].attrs['name'].item()
if isinstance(fname, bytes):
fname = fname.decode('utf8')
except KeyError:
fname = ''
# %% camera window
with h5py.File(windfn, 'r') as f:
fwind = interp1d(f['/lamb'], np.log(f['/T']), kind='linear')
# %% quantum efficiency
with h5py.File(qefn, 'r') as f:
fqe = interp1d(f['/lamb'], np.log(f['/QE']), kind='linear')
# %% collect results into DataArray
T = xarray.Dataset({'filter': ('wavelength_nm', np.exp(fbg3(newLambda))),
'window': ('wavelength_nm', np.exp(fwind(newLambda))),
'qe': ('wavelength_nm', np.exp(fqe(newLambda))),
'atm': ('wavelength_nm', atmTinterp), },
coords={'wavelength_nm': newLambda},
attrs={'filename': fname})
T['sysNObg3'] = T['window'] * T['qe'] * T['atm']
T['sys'] = T['sysNObg3'] * T['filter']
return T
def test_transmittance():
angles = 60
c1 = {'model': 5,
'h1': 0, # of observer
'angle': angles, # of observer
'wlshort': 200,
'wllong': 30000,
'wlstep': 20,
}
# %%
TR = lowtran.transmittance(c1)
assert TR.wavelength_nm[[0, -1]].values == approx((30303.03, 200), rel=0.001)
assert TR['transmission'][0, [1000, 1200], 0].values == approx([0.726516, 0.527192], rel=0.001)
def test_transmittance():
vlim = (200, 30000)
angles = 60
c1 = {'model': 5,
'h1': 0, # of observer
'angle': angles, # of observer
'wlnmlim': vlim,
}
# %%
TR = lowtran.transmittance(c1)
assert_allclose(TR.wavelength_nm[[0, -1]],
(30303.03, 200), rtol=1e-6)
assert_allclose(TR['transmission'][0, [1000, 1200], 0],
[0.002074, 0.924557], rtol=0.001)
def main():
p = ArgumentParser(description='Lowtran 7 interface')
p.add_argument('-z',
'--obsalt',
help='altitude of observer [km]',
type=float,
default=0.)
p.add_argument('-a',
'--zenang',
help='observer zenith angle [deg]',
type=float,
nargs='+',
default=[0, 60, 80])
p.add_argument('-s',
'--short',
help='shortest wavelength nm ',
type=float,
default=200)
p.add_argument('-l',
'--long',
help='longest wavelength cm^-1 ',
type=float,
default=30000)
p.add_argument('-step',
help='wavelength step size cm^-1',
type=float,
default=20)
p.add_argument('--model',
help='0-6, see Card1 "model" reference. 5=subarctic winter',
type=int,
default=5)
P = p.parse_args()
c1 = {
'model': P.model,
'h1': P.obsalt,
'angle': P.zenang,
'wlshort': P.short,
'wllong': P.long,
'wlstep': P.step,
}
TR = lowtran.transmittance(c1)
plottrans(TR, c1)
show()
def main():
p = ArgumentParser(description='Lowtran 7 interface')
p.add_argument('-z', '--obsalt', help='altitude of observer [km]', type=float, default=0.)
p.add_argument('-a', '--zenang', help='observer zenith angle [deg]', type=float, nargs='+', default=[0, 60, 80])
p.add_argument('-w', '--wavelen', help='wavelength range nm (start,stop)', type=float, nargs=2, default=(200, 30000))
p.add_argument('--model', help='0-6, see Card1 "model" reference. 5=subarctic winter', type=int, default=5)
P = p.parse_args()
c1 = {'model': P.model,
'h1': P.obsalt,
'angle': P.zenang,
'wlnmlim': P.wavelen,
}
TR = lowtran.transmittance(c1)
plottrans(TR, c1)
show()
# absorbing gases correction
####################################
import lowtran
import lowtran.plots as lp
lowtran.nm2lt7(200, 2500, 20)
c1 = {
'model': 6,
'h1': 0,
'angle': [0, 30, 60],
'wlshort': 300,
'wllong': 2600,
'wlstep': 5,
}
TR = lowtran.transmittance(c1)
lp.plottrans(TR, c1)
TR = lowtran.radiance(c1)
lp.plotradiance(TR, c1)
TR = lowtran.irradiance(c1)
lp.plotirrad(TR, c1)
s = SixS()
s.geometry.solar_z = sza
s.geometry.solar_a = 0
s.geometry.view_z = vza
s.geometry.view_a = azi
s.aero_profile = AeroProfile.PredefinedType(AeroProfile.Maritime)
parameter = 'apparent_radiance'
parameter = 'direct_solar_irradiance'
params = [