def add_almanac(self, data):
almanac = Almanac(
time.time(),
float(weecfg.get_station_info(self.config_dict)['latitude']),
float(weecfg.get_station_info(self.config_dict)['longitude']),
float(weecfg.get_station_info(self.config_dict)['altitude'][0]))
data["sunrise"] = almanac.sun.rise.raw
data["sunset"] = almanac.sun.set.raw
data["sunaz"] = almanac.sun.az
data["sunalt"] = almanac.sun.alt
return data
def get_scalar(self, obs_type, record, db_manager):
# We only know how to calculate some sun and moon related stuff. For everything else, raise an exception UnknownType
if obs_type not in ('sun_altitude', 'sun_azimuth'):
raise weewx.UnknownType(obs_type)
# we only report sun values if the sun is above the horizon
almanac = Almanac(record['dateTime'], self.lat, self.lng,
0) # TODO convert alt to meters
sun_altitude = almanac.sun.alt
if obs_type == 'sun_altitude':
value = ValueTuple(sun_altitude if sun_altitude >= 0 else None,
'degree_compass', 'group_direction')
elif obs_type == 'sun_azimuth':
value = ValueTuple(almanac.sun.az if sun_altitude >= 0 else None,
'degree_compass', 'group_direction')
# We have the calculated values as ValueTuples. Convert them back to the units used by
# the incoming record and return it
return weewx.units.convertStd(value, record['usUnits'])
def get_data(self, now_ts, last_ts):
""" read data from almanac """
try:
alm = Almanac(time.time(), 53.605963, 11.341407, 53.2)
son_alt = alm.sun.earth_distance
sun_alt = alm.sun.alt
mon_alt = alm.moon.alt
mer_alt = alm.mercury.alt
ven_alt = alm.venus.alt
mar_alt = alm.mars.alt
jup_alt = alm.jupiter.alt
sat_alt = alm.saturn.alt
ura_alt = alm.uranus.alt
nep_alt = alm.neptune.alt
plu_alt = alm.pluto.alt
except:
sr = None
record = {}
record['dateTime'] = now_ts # required
record['usUnits'] = weewx.METRIC # required
record['interval'] = int((now_ts - last_ts) / 60) # required
record['hor_alt'] = 0.0
record['son_alt'] = son_alt
record['sun_alt'] = sun_alt
record['mon_alt'] = mon_alt
record['mer_alt'] = mer_alt
record['ven_alt'] = ven_alt
record['mar_alt'] = mar_alt
record['jup_alt'] = jup_alt
record['sat_alt'] = sat_alt
record['ura_alt'] = ura_alt
record['nep_alt'] = nep_alt
record['plu_alt'] = plu_alt
return record
def solar_rad_RS(lat, lon, altitude_m, ts=None, atc=0.8):
"""Calculate maximum solar radiation
Ryan-Stolzenbach, MIT 1972
http://www.ecy.wa.gov/programs/eap/models.html
lat, lon - latitude and longitude in decimal degrees
altitude_m - altitude in meters
ts - time as unix epoch
atc - atmospheric transmission coefficient (0.7-0.91)
Example:
>>> for t in range(0,24):
... print "%.2f" % solar_rad_RS(42, -72, 0, t*3600+1422936471)
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.09
79.31
234.77
369.80
455.66
481.15
443.44
346.81
204.64
52.63
0.00
0.00
0.00
0.00
0.00
0.00
"""
from weewx.almanac import Almanac
if atc < 0.7 or atc > 0.91:
atc = 0.8
if ts is None:
ts = time.time()
sr = 0.0
try:
alm = Almanac(ts, lat, lon, altitude_m)
el = alm.sun.alt # solar elevation degrees from horizon
R = alm.sun.earth_distance
z = altitude_m
nrel = 1367.0 # NREL solar constant, W/m^2
sinal = math.sin(math.radians(el))
if sinal >= 0: # sun must be above horizon
rm = math.pow(
(288.0 - 0.0065 * z) / 288.0,
5.256) / (sinal + 0.15 * math.pow(el + 3.885, -1.253))
toa = nrel * sinal / (R * R)
sr = toa * math.pow(atc, rm)
except (AttributeError, ValueError, OverflowError):
sr = None
return sr
def solar_rad_Bras(lat, lon, altitude_m, ts=None, nfac=2):
"""Calculate maximum solar radiation using Bras method
http://www.ecy.wa.gov/programs/eap/models.html
lat, lon - latitude and longitude in decimal degrees
altitude_m - altitude in meters
ts - timestamp as unix epoch
nfac - atmospheric turbidity (2=clear, 4-5=smoggy)
Example:
>>> for t in range(0,24):
... print "%.2f" % solar_rad_Bras(42, -72, 0, t*3600+1422936471)
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
1.86
100.81
248.71
374.68
454.90
478.76
443.47
353.23
220.51
73.71
0.00
0.00
0.00
0.00
0.00
0.00
"""
from weewx.almanac import Almanac
if ts is None:
ts = time.time()
sr = 0.0
try:
alm = Almanac(ts, lat, lon, altitude_m)
el = alm.sun.alt # solar elevation degrees from horizon
R = alm.sun.earth_distance
# NREL solar constant W/m^2
nrel = 1367.0
# radiation on horizontal surface at top of atmosphere (bras eqn 2.9)
sinel = math.sin(math.radians(el))
io = sinel * nrel / (R * R)
if sinel >= 0:
# optical air mass (bras eqn 2.22)
m = 1.0 / (sinel + 0.15 * math.pow(el + 3.885, -1.253))
# molecular scattering coefficient (bras eqn 2.26)
a1 = 0.128 - 0.054 * math.log(m) / math.log(10.0)
# clear-sky radiation at earth surface W / m^2 (bras eqn 2.25)
sr = io * math.exp(-nfac * a1 * m)
except (AttributeError, ValueError, OverflowError):
sr = None
return sr
