MIDC SPA Calculator
Compute the solar position from universal time
and location using NREL's
Solar Position Algorithm (SPA)
.
Required input values:
Enter start date:
Year:
Month:
January
February
March
April
May
June
July
August
September
October
November
December
Day:
1
2
3
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5
6
7
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31
Enter end date:
Year:
Month:
January
February
March
April
May
June
July
August
September
October
November
December
Day:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Enter output time interval:
Interval:
1
2
5
10
15
30
60
Units:
Second
Minute
Enter site location information:
Observer latitude (negative south of equator) [degrees]
Observer longitude (negative west of Greenwich) [degrees]
Observer time zone (negative west of Greenwich) [hours]
Observer elevation [meters]
Annual average local pressure [millibars]
Annual average local temperature [degrees Celsius]
ΔT
= Terrestrial Time (TT) - Universal Time (UT) [seconds]
Optional input values:
Surface azimuth rotation (measured from south to projection
of surface normal on horizontal plane, negative west) [degrees]
Surface slope (measured from the horizontal plane) [degrees]
Atmospheric refraction at sunrise and sunset [degrees]
Check desired final output values:
Topocentric zenith angle [degrees]
Topocentric azimuth angle (eastward from north) [ 0 to 360 degrees]
Topocentric azimuth angle (westward from south) [-180 to 180 degrees]
Surface incidence angle [degrees]
Local sunrise time (+/- 30 seconds) [fractional hour]
Local sun transit time (or solar noon) [fractional hour]
Local sunset time (+/- 30 seconds) [fractional hour]
Check desired intermediate output values:
Julian day
Julian century
Julian ephemeris day
Julian ephemeris century
Julian ephemeris millennium
Earth heliocentric longitude [degrees]
Earth heliocentric latitude [degrees]
Earth radius vector [Astronomical Units, AU]
Geocentric longitude [degrees]
Geocentric latitude [degrees]
Mean elongation (moon-sun) [degrees]
Mean anomaly (sun) [degrees]
Mean anomaly (moon) [degrees]
Argument latitude (moon) [degrees]
Ascending longitude (moon) [degrees]
Nutation longitude [degrees]
Nutation obliquity [degrees]
Ecliptic mean obliquity [arc seconds]
Ecliptic true obliquity [degrees]
Aberration correction [degrees]
Apparent sun longitude [degrees]
Greenwich mean sidereal time [degrees]
Greenwich sidereal time [degrees]
Geocentric sun right ascension [degrees]
Geocentric sun declination [degrees]
Observer hour angle [degrees]
Sun equatorial horizontal parallax [degrees]
Sun right ascension parallax [degrees]
Topocentric sun declination [degrees]
Topocentric sun right ascension [degrees]
Topocentric local hour angle [degrees]
Topocentric elevation angle (uncorrected) [degrees]
Atmospheric refraction correction [degrees]
Topocentric elevation angle (corrected) [degrees]
Equation of time [minutes]
Sunrise hour angle [degrees]
Sunset hour angle [degrees]
Sun transit altitude [degrees]
Data output type:
ASCII Text
ZIP Compressed
Please read the
disclaimer
and
copyright notice
before using this product.
For more more information about
SPA and the C source code
[
NREL
] [
MID
C
] [
Solar Calculators
]