58 lines
2.6 KiB
Python
58 lines
2.6 KiB
Python
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import astropy.units as u
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import numpy as np
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from astropy.coordinates import EarthLocation, AltAz
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from astropy.coordinates import get_sun
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def sun_angles_astropy(lat, lon, h, utc):
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loc = EarthLocation(lat=lat*u.deg, lon=lon*u.deg, height=h*u.m)
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ref = AltAz(obstime=utc, location=loc)
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sun_pos = get_sun(utc).transform_to(ref)
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AZ = sun_pos.az.degree
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ELV = sun_pos.alt.degree
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return AZ, ELV
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def sun_angles_analytical(lat, lon, utc):
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JD = utc.jd
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JC = (JD - 2451545) / 36525
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GML = (280.46646 + JC * (36000.76983 + JC * 0.0003032)) % 360
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GMA = 357.52911 + JC * (35999.05029 - 0.0001537 * JC)
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EEO = 0.016708634 - JC * (0.000042037 + 0.0000001267 * JC)
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SEC = np.sin(np.deg2rad(GMA)) * (1.914602 - JC * (0.004817 + 0.000014 * JC)) + np.sin(np.deg2rad(2 * GMA)) * (
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0.019993 - 0.000101 * JC) + np.sin(np.deg2rad(3 * GMA)) * 0.000289
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STL = GML + SEC
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# STA = GMA + SEC
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# SRV = (1.000001018 * (1 - EEO ** 2)) / (1 + EEO * np.cos(np.deg2rad(STA)))
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SAL = STL - 0.00569 - 0.00478 * np.sin(np.deg2rad(125.04 - 1934.136 * JC))
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MOE = 23 + (26 + (21.448 - JC * (46.815 + JC * (0.00059 - JC * 0.001813))) / 60) / 60
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OC = MOE + 0.00256 * np.cos(np.deg2rad(125.04 - 1934.136 * JC))
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# SRA = np.rad2deg(np.arctan2(np.cos(np.deg2rad(OC)) * np.sin(np.deg2rad(SAL)), np.cos(np.deg2rad(SAL)))) # radian
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SD = np.rad2deg(np.arcsin(np.sin(np.deg2rad(OC)) * np.sin(np.deg2rad(SAL)))) # radian
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var_y = np.tan(np.deg2rad(OC / 2)) ** 2
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EOT = 4 * np.rad2deg(
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var_y * np.sin(2 * np.deg2rad(GML)) - 2 * EEO * np.sin(np.deg2rad(GMA)) + 4 * EEO * var_y * np.sin(
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np.deg2rad(GMA)) * np.cos(2 * np.deg2rad(GML)) - 0.5 * var_y ** 2 * np.sin(
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4 * np.deg2rad(GML)) - 1.25 * EEO ** 2 * np.sin(2 * np.deg2rad(GMA)))
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TST = (((JD - 0.5) % 1) * 1440 + EOT + 4 * lon) % 1440
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if TST / 4 < 0:
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HA = TST / 4 + 180
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else:
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HA = TST / 4 - 180
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SZA = np.rad2deg(np.arccos(
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np.sin(np.deg2rad(lat)) * np.sin(np.deg2rad(SD)) + np.cos(np.deg2rad(lat)) * np.cos(np.deg2rad(SD)) * np.cos(
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np.deg2rad(HA))))
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SEA = 90 - SZA
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if HA > 0:
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SAA = (np.rad2deg(np.arccos(((np.sin(np.deg2rad(lat)) * np.cos(np.deg2rad(SZA))) - np.sin(np.deg2rad(SD))) / (
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np.cos(np.deg2rad(lat)) * np.sin(np.deg2rad(SZA))))) + 180) % 360
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else:
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SAA = (540 - np.rad2deg(np.arccos(
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((np.sin(np.deg2rad(lat)) * np.cos(np.deg2rad(SZA))) - np.sin(np.deg2rad(SD))) / (
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np.cos(np.deg2rad(lat)) * np.sin(np.deg2rad(SZA)))))) % 360
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return SAA, SEA
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