def _get_sunlight_coverage(area_def, start_time, overpass=None):
"""Get the sunlight coverage of *area_def* at *start_time* as a value between 0 and 1."""
if area_def.proj_dict.get('proj') == 'geos':
adp = Boundary(*get_geostationary_bounding_box(
area_def, nb_points=100)).contour_poly
else:
adp = AreaDefBoundary(area_def, frequency=100).contour_poly
poly = get_twilight_poly(start_time)
if overpass is not None:
ovp = overpass.boundary.contour_poly
cut_area_poly = adp.intersection(ovp)
else:
cut_area_poly = adp
if cut_area_poly is None:
if not adp._is_inside(ovp):
return 0.0
else:
# Should already have been taken care of in pyresample.spherical.intersection
cut_area_poly = adp
daylight = cut_area_poly.intersection(poly)
if daylight is None:
if sun_zenith_angle(start_time, *area_def.get_lonlat(0, 0)) < 90:
return 1.0
else:
return 0.0
else:
daylight_area = daylight.area()
total_area = adp.area()
return daylight_area / total_area
def _get_sunlight_coverage(area_def,
start_time,
sza_threshold=90,
overpass=None):
"""Get the sunlight coverage of *area_def* at *start_time* as a value between 0 and 1."""
if isinstance(area_def, SwathDefinition):
lons, lats = area_def.get_lonlats()
freq = int(lons.shape[-1] * 0.10)
lons, lats = da.compute(lons[::freq, ::freq], lats[::freq, ::freq])
adp = Boundary(lons.ravel(), lats.ravel()).contour_poly
elif area_def.is_geostationary:
adp = Boundary(*get_geostationary_bounding_box(
area_def, nb_points=100)).contour_poly
else:
adp = AreaDefBoundary(area_def, frequency=100).contour_poly
poly = get_twilight_poly(start_time)
if overpass is not None:
ovp = overpass.boundary.contour_poly
cut_area_poly = adp.intersection(ovp)
else:
cut_area_poly = adp
if cut_area_poly is None:
if not adp._is_inside(ovp):
return 0.0
else:
# Should already have been taken care of in pyresample.spherical.intersection
cut_area_poly = adp
daylight = cut_area_poly.intersection(poly)
if daylight is None:
if sun_zenith_angle(start_time, *area_def.get_lonlat(
0, 0)) < sza_threshold:
return 1.0
else:
return 0.0
else:
daylight_area = daylight.area()
total_area = adp.area()
return daylight_area / total_area