|
|
#ifndef __SOLPOS00__
|
|
|
#define __SOLPOS00__
|
|
|
|
|
|
|
|
|
#include <math.h>
|
|
|
#include <string.h>
|
|
|
#include <stdio.h>
|
|
|
|
|
|
/* Note added by B. Rideout */
|
|
|
/* Taken from National Renewable Energy Laboratory */
|
|
|
/* http://rredc.nrel.gov/solar/codes_algs/solpos/ */
|
|
|
/* Modified slightly to remove compiler warnings */
|
|
|
/* Dec. 19, 2002 */
|
|
|
|
|
|
|
|
|
/*============================================================================
|
|
|
*
|
|
|
* NAME: solpos00.h
|
|
|
*
|
|
|
* Contains:
|
|
|
* S_solpos (computes the solar position and intensity
|
|
|
* from time and place)
|
|
|
* INPUTS: (from posdata)
|
|
|
* year, month, day, hour, minute, second,
|
|
|
* latitude, longitude, timezone, interval
|
|
|
* OPTIONAL: (from posdata; defaults from S_init function)
|
|
|
* press DEFAULT 1013.0 (standard pressure)
|
|
|
* temp DEFAULT 10.0 (standard temperature)
|
|
|
* tilt DEFAULT 0.0 (horizontal panel)
|
|
|
* aspect DEFAULT 180.0 (South-facing panel)
|
|
|
* sbwid DEFAULT 7.6 (shadowband width)
|
|
|
* sbrad DEFAULT 31.7 (shadowband radius)
|
|
|
* sbsky DEFAULT 0.04 (shadowband sky factor)
|
|
|
*
|
|
|
* OUTPUTS: (posdata) daynum, amass, ampress, azim, cosinc,
|
|
|
* elevref, etr, etrn, etrtilt, prime,
|
|
|
* sbcf, sretr, ssetr, unprime, zenref
|
|
|
*
|
|
|
* RETURNS: Long int status code (defined in solpos.h)
|
|
|
*
|
|
|
* Usage:
|
|
|
* In calling program, along with other 'includes', insert:
|
|
|
*
|
|
|
* #include "solpos.h"
|
|
|
*
|
|
|
* Martin Rymes
|
|
|
* National Renewable Energy Laboratory
|
|
|
* 25 March 1998
|
|
|
*----------------------------------------------------------------------------*/
|
|
|
|
|
|
/*============================================================================
|
|
|
*
|
|
|
* Define the function codes
|
|
|
*
|
|
|
*----------------------------------------------------------------------------*/
|
|
|
#define L_DOY 0x0001
|
|
|
#define L_GEOM 0x0002
|
|
|
#define L_ZENETR 0x0004
|
|
|
#define L_SSHA 0x0008
|
|
|
#define L_SBCF 0x0010
|
|
|
#define L_TST 0x0020
|
|
|
#define L_SRSS 0x0040
|
|
|
#define L_SOLAZM 0x0080
|
|
|
#define L_REFRAC 0x0100
|
|
|
#define L_AMASS 0x0200
|
|
|
#define L_PRIME 0x0400
|
|
|
#define L_TILT 0x0800
|
|
|
#define L_ETR 0x1000
|
|
|
#define L_ALL 0xFFFF
|
|
|
|
|
|
/*============================================================================
|
|
|
*
|
|
|
* Define the bit-wise masks for each function
|
|
|
*
|
|
|
*----------------------------------------------------------------------------*/
|
|
|
#define S_DOY ( L_DOY )
|
|
|
#define S_GEOM ( L_GEOM | S_DOY )
|
|
|
#define S_ZENETR ( L_ZENETR | S_GEOM )
|
|
|
#define S_SSHA ( L_SSHA | S_GEOM )
|
|
|
#define S_SBCF ( L_SBCF | S_SSHA )
|
|
|
#define S_TST ( L_TST | S_GEOM )
|
|
|
#define S_SRSS ( L_SRSS | S_SSHA | S_TST )
|
|
|
#define S_SOLAZM ( L_SOLAZM | S_ZENETR )
|
|
|
#define S_REFRAC ( L_REFRAC | S_ZENETR )
|
|
|
#define S_AMASS ( L_AMASS | S_REFRAC )
|
|
|
#define S_PRIME ( L_PRIME | S_AMASS )
|
|
|
#define S_TILT ( L_TILT | S_SOLAZM | S_REFRAC )
|
|
|
#define S_ETR ( L_ETR | S_REFRAC )
|
|
|
#define S_ALL ( L_ALL )
|
|
|
|
|
|
|
|
|
/*============================================================================
|
|
|
*
|
|
|
* Enumerate the error codes
|
|
|
* (Bit positions are from least significant to most significant)
|
|
|
*
|
|
|
*----------------------------------------------------------------------------*/
|
|
|
/* Code Bit Parameter Range
|
|
|
=============== === =================== ============= */
|
|
|
enum {S_YEAR_ERROR, /* 0 year 1950 - 2050 */
|
|
|
S_MONTH_ERROR, /* 1 month 1 - 12 */
|
|
|
S_DAY_ERROR, /* 2 day-of-month 1 - 31 */
|
|
|
S_DOY_ERROR, /* 3 day-of-year 1 - 366 */
|
|
|
S_HOUR_ERROR, /* 4 hour 0 - 24 */
|
|
|
S_MINUTE_ERROR, /* 5 minute 0 - 59 */
|
|
|
S_SECOND_ERROR, /* 6 second 0 - 59 */
|
|
|
S_TZONE_ERROR, /* 7 time zone -12 - 12 */
|
|
|
S_INTRVL_ERROR, /* 8 interval (seconds) 0 - 28800 */
|
|
|
S_LAT_ERROR, /* 9 latitude -90 - 90 */
|
|
|
S_LON_ERROR, /* 10 longitude -180 - 180 */
|
|
|
S_TEMP_ERROR, /* 11 temperature (deg. C) -100 - 100 */
|
|
|
S_PRESS_ERROR, /* 12 pressure (millibars) 0 - 2000 */
|
|
|
S_TILT_ERROR, /* 13 tilt -90 - 90 */
|
|
|
S_ASPECT_ERROR, /* 14 aspect -360 - 360 */
|
|
|
S_SBWID_ERROR, /* 15 shadow band width (cm) 1 - 100 */
|
|
|
S_SBRAD_ERROR, /* 16 shadow band radius (cm) 1 - 100 */
|
|
|
S_SBSKY_ERROR}; /* 17 shadow band sky factor -1 - 1 */
|
|
|
|
|
|
struct posdata
|
|
|
{
|
|
|
/***** ALPHABETICAL LIST OF COMMON VARIABLES *****/
|
|
|
/* Each comment begins with a 1-column letter code:
|
|
|
I: INPUT variable
|
|
|
O: OUTPUT variable
|
|
|
T: TRANSITIONAL variable used in the algorithm,
|
|
|
of interest only to the solar radiation
|
|
|
modelers, and available to you because you
|
|
|
may be one of them.
|
|
|
|
|
|
The FUNCTION column indicates which sub-function
|
|
|
within solpos must be switched on using the
|
|
|
"function" parameter to calculate the desired
|
|
|
output variable. All function codes are
|
|
|
defined in the solpos.h file. The default
|
|
|
S_ALL switch calculates all output variables.
|
|
|
Multiple functions may be or'd to create a
|
|
|
composite function switch. For example,
|
|
|
(S_TST | S_SBCF). Specifying only the functions
|
|
|
for required output variables may allow solpos
|
|
|
to execute more quickly.
|
|
|
|
|
|
The S_DOY mask works as a toggle between the
|
|
|
input date represented as a day number (daynum)
|
|
|
or as month and day. To set the switch (to
|
|
|
use daynum input), the function is or'd; to
|
|
|
clear the switch (to use month and day input),
|
|
|
the function is inverted and and'd.
|
|
|
|
|
|
For example:
|
|
|
pdat->function |= S_DOY (sets daynum input)
|
|
|
pdat->function &= ~S_DOY (sets month and day input)
|
|
|
|
|
|
Whichever date form is used, S_solpos will
|
|
|
calculate and return the variables(s) of the
|
|
|
other form. See the soltest.c program for
|
|
|
other examples. */
|
|
|
|
|
|
/* VARIABLE I/O Function Description */
|
|
|
/* ------------- ---- ---------- ---------------------------------------*/
|
|
|
|
|
|
int day; /* I/O: S_DOY Day of month (May 27 = 27, etc.)
|
|
|
solpos will CALCULATE this by default,
|
|
|
or will optionally require it as input
|
|
|
depending on the setting of the S_DOY
|
|
|
function switch. */
|
|
|
int daynum; /* I/O: S_DOY Day number (day of year; Feb 1 = 32 )
|
|
|
solpos REQUIRES this by default, but
|
|
|
will optionally calculate it from
|
|
|
month and day depending on the setting
|
|
|
of the S_DOY function switch. */
|
|
|
int function; /* I: Switch to choose functions for desired
|
|
|
output. */
|
|
|
int hour; /* I: Hour of day, 0 - 23, DEFAULT = 12 */
|
|
|
int interval; /* I: Interval of a measurement period in
|
|
|
seconds. Forces solpos to use the
|
|
|
time and date from the interval
|
|
|
midpoint. The INPUT time (hour,
|
|
|
minute, and second) is assumed to
|
|
|
be the END of the measurement
|
|
|
interval. */
|
|
|
int minute; /* I: Minute of hour, 0 - 59, DEFAULT = 0 */
|
|
|
int month; /* I/O: S_DOY Month number (Jan = 1, Feb = 2, etc.)
|
|
|
solpos will CALCULATE this by default,
|
|
|
or will optionally require it as input
|
|
|
depending on the setting of the S_DOY
|
|
|
function switch. */
|
|
|
int second; /* I: Second of minute, 0 - 59, DEFAULT = 0 */
|
|
|
int year; /* I: 4-digit year (2-digit year is NOT
|
|
|
allowed */
|
|
|
|
|
|
/***** FLOATS *****/
|
|
|
|
|
|
float amass; /* O: S_AMASS Relative optical airmass */
|
|
|
float ampress; /* O: S_AMASS Pressure-corrected airmass */
|
|
|
float aspect; /* I: Azimuth of panel surface (direction it
|
|
|
faces) N=0, E=90, S=180, W=270,
|
|
|
DEFAULT = 180 */
|
|
|
float azim; /* O: S_SOLAZM Solar azimuth angle: N=0, E=90, S=180,
|
|
|
W=270 */
|
|
|
float cosinc; /* O: S_TILT Cosine of solar incidence angle on
|
|
|
panel */
|
|
|
float coszen; /* O: S_REFRAC Cosine of refraction corrected solar
|
|
|
zenith angle */
|
|
|
float dayang; /* T: S_GEOM Day angle (daynum*360/year-length)
|
|
|
degrees */
|
|
|
float declin; /* T: S_GEOM Declination--zenith angle of solar noon
|
|
|
at equator, degrees NORTH */
|
|
|
float eclong; /* T: S_GEOM Ecliptic longitude, degrees */
|
|
|
float ecobli; /* T: S_GEOM Obliquity of ecliptic */
|
|
|
float ectime; /* T: S_GEOM Time of ecliptic calculations */
|
|
|
float elevetr; /* O: S_ZENETR Solar elevation, no atmospheric
|
|
|
correction (= ETR) */
|
|
|
float elevref; /* O: S_REFRAC Solar elevation angle,
|
|
|
deg. from horizon, refracted */
|
|
|
float eqntim; /* T: S_TST Equation of time (TST - LMT), minutes */
|
|
|
float erv; /* T: S_GEOM Earth radius vector
|
|
|
(multiplied to solar constant) */
|
|
|
float etr; /* O: S_ETR Extraterrestrial (top-of-atmosphere)
|
|
|
W/sq m global horizontal solar
|
|
|
irradiance */
|
|
|
float etrn; /* O: S_ETR Extraterrestrial (top-of-atmosphere)
|
|
|
W/sq m direct normal solar
|
|
|
irradiance */
|
|
|
float etrtilt; /* O: S_TILT Extraterrestrial (top-of-atmosphere)
|
|
|
W/sq m global irradiance on a tilted
|
|
|
surface */
|
|
|
float gmst; /* T: S_GEOM Greenwich mean sidereal time, hours */
|
|
|
float hrang; /* T: S_GEOM Hour angle--hour of sun from solar noon,
|
|
|
degrees WEST */
|
|
|
float julday; /* T: S_GEOM Julian Day of 1 JAN 2000 minus
|
|
|
2,400,000 days (in order to regain
|
|
|
single precision) */
|
|
|
float latitude; /* I: Latitude, degrees north (south negative) */
|
|
|
float longitude; /* I: Longitude, degrees east (west negative) */
|
|
|
float lmst; /* T: S_GEOM Local mean sidereal time, degrees */
|
|
|
float mnanom; /* T: S_GEOM Mean anomaly, degrees */
|
|
|
float mnlong; /* T: S_GEOM Mean longitude, degrees */
|
|
|
float rascen; /* T: S_GEOM Right ascension, degrees */
|
|
|
float press; /* I: Surface pressure, millibars, used for
|
|
|
refraction correction and ampress */
|
|
|
float prime; /* O: S_PRIME Factor that normalizes Kt, Kn, etc. */
|
|
|
float sbcf; /* O: S_SBCF Shadow-band correction factor */
|
|
|
float sbwid; /* I: Shadow-band width (cm) */
|
|
|
float sbrad; /* I: Shadow-band radius (cm) */
|
|
|
float sbsky; /* I: Shadow-band sky factor */
|
|
|
float solcon; /* I: Solar constant (NREL uses 1367 W/sq m) */
|
|
|
float ssha; /* T: S_SRHA Sunset(/rise) hour angle, degrees */
|
|
|
float sretr; /* O: S_SRSS Sunrise time, minutes from midnight,
|
|
|
local, WITHOUT refraction */
|
|
|
float ssetr; /* O: S_SRSS Sunset time, minutes from midnight,
|
|
|
local, WITHOUT refraction */
|
|
|
float temp; /* I: Ambient dry-bulb temperature, degrees C,
|
|
|
used for refraction correction */
|
|
|
float tilt; /* I: Degrees tilt from horizontal of panel */
|
|
|
float timezone; /* I: Time zone, east (west negative).
|
|
|
USA: Mountain = -7, Central = -6, etc. */
|
|
|
float tst; /* T: S_TST True solar time, minutes from midnight */
|
|
|
float tstfix; /* T: S_TST True solar time - local standard time */
|
|
|
float unprime; /* O: S_PRIME Factor that denormalizes Kt', Kn', etc. */
|
|
|
float utime; /* T: S_GEOM Universal (Greenwich) standard time */
|
|
|
float zenetr; /* T: S_ZENETR Solar zenith angle, no atmospheric
|
|
|
correction (= ETR) */
|
|
|
float zenref; /* O: S_REFRAC Solar zenith angle, deg. from zenith,
|
|
|
refracted */
|
|
|
};
|
|
|
|
|
|
/* For users that wish to access individual functions, the following table
|
|
|
lists all output and transition variables, the L_ mask for the function
|
|
|
that calculates them, and all the input variables required by that function.
|
|
|
The function variable is set to the L_ mask, which will force S_solpos to
|
|
|
only call the required function. L_ masks may be ORed as desired.
|
|
|
|
|
|
VARIABLE Mask Required Variables
|
|
|
--------- ---------- ---------------------------------------
|
|
|
amass L_AMASS zenref, press
|
|
|
ampress L_AMASS zenref, press
|
|
|
azim L_SOLAZM elevetr, declin, latitude, hrang
|
|
|
cosinc L_TILT azim, aspect, tilt, zenref, coszen,etrn
|
|
|
coszen L_REFRAC elevetr, press, temp
|
|
|
dayang L_GEOM All date, time, and location inputs
|
|
|
declin L_GEOM All date, time, and location inputs
|
|
|
eclong L_GEOM All date, time, and location inputs
|
|
|
ecobli L_GEOM All date, time, and location inputs
|
|
|
ectime L_GEOM All date, time, and location inputs
|
|
|
elevetr L_ZENETR declin, latitude, hrang
|
|
|
elevref L_REFRAC elevetr, press, temp
|
|
|
eqntim L_TST hrang, hour, minute, second, interval
|
|
|
erv L_GEOM All date, time, and location inputs
|
|
|
etr L_ETR coszen, solcon, erv
|
|
|
etrn L_ETR coszen, solcon, erv
|
|
|
etrtilt L_TILT azim, aspect, tilt, zenref, coszen, etrn
|
|
|
gmst L_GEOM All date, time, and location inputs
|
|
|
hrang L_GEOM All date, time, and location inputs
|
|
|
julday L_GEOM All date, time, and location inputs
|
|
|
lmst L_GEOM All date, time, and location inputs
|
|
|
mnanom L_GEOM All date, time, and location inputs
|
|
|
mnlong L_GEOM All date, time, and location inputs
|
|
|
rascen L_GEOM All date, time, and location inputs
|
|
|
prime L_PRIME amass
|
|
|
sbcf L_SBCF latitude, declin, ssha, sbwid, sbrad, sbsky
|
|
|
ssha L_SRHA latitude, declin
|
|
|
sretr L_SRSS ssha, tstfix
|
|
|
ssetr L_SRSS ssha, tstfix
|
|
|
tst L_TST hrang, hour, minute, second, interval
|
|
|
tstfix L_TST hrang, hour, minute, second, interval
|
|
|
unprime L_PRIME amass
|
|
|
utime L_GEOM All date, time, and location inputs
|
|
|
zenetr L_ZENETR declination, latitude, hrang
|
|
|
zenref L_REFRAC elevetr, press, temp
|
|
|
*/
|
|
|
|
|
|
|
|
|
/*============================================================================
|
|
|
* Long int function S_solpos, adapted from the NREL VAX solar libraries
|
|
|
*
|
|
|
* This function calculates the apparent solar position and intensity
|
|
|
* (theoretical maximum solar energy) based on the date, time, and
|
|
|
* location on Earth. (DEFAULT values are from the optional S_posinit
|
|
|
* function.)
|
|
|
*
|
|
|
* Requires:
|
|
|
* Date and time:
|
|
|
* year
|
|
|
* month (optional without daynum)
|
|
|
* day (optional without daynum)
|
|
|
* daynum
|
|
|
* hour
|
|
|
* minute
|
|
|
* second
|
|
|
* Location:
|
|
|
* latitude
|
|
|
* longitude
|
|
|
* Location/time adjuster:
|
|
|
* timezone
|
|
|
* Atmospheric pressure and temperature:
|
|
|
* press DEFAULT 1013.0 mb
|
|
|
* temp DEFAULT 10.0 degrees C
|
|
|
* Tilt of flat surface that receives solar energy:
|
|
|
* aspect DEFAULT 180 (South)
|
|
|
* tilt DEFAULT 0 (Horizontal)
|
|
|
* Shadow band parameters:
|
|
|
* sbwid DEFAULT 7.6 cm
|
|
|
* sbrad DEFAULT 31.7 cm
|
|
|
* sbsky DEFAULT 0.04
|
|
|
* Functionality
|
|
|
* function DEFAULT S_ALL (all output parameters computed)
|
|
|
*
|
|
|
* Returns:
|
|
|
* everything defined at the top of this listing.
|
|
|
*----------------------------------------------------------------------------*/
|
|
|
long S_solpos (struct posdata *pdat);
|
|
|
|
|
|
/*============================================================================
|
|
|
* Void function S_init
|
|
|
*
|
|
|
* This function initiates all of the input functions to S_Solpos().
|
|
|
* NOTE: This function is optional if you initialize all input parameters
|
|
|
* in your calling code.
|
|
|
*
|
|
|
* Requires: Pointer to a posdata structure, members of which are
|
|
|
* initialized.
|
|
|
*
|
|
|
* Returns: Void
|
|
|
*
|
|
|
*----------------------------------------------------------------------------*/
|
|
|
void S_init(struct posdata *pdat);
|
|
|
|
|
|
|
|
|
/*============================================================================
|
|
|
* Void function S_decode
|
|
|
*
|
|
|
* This function decodes the error codes from S_solpos return value
|
|
|
*
|
|
|
* INPUTS: Long integer S_solpos return value, struct posdata*
|
|
|
*
|
|
|
* OUTPUTS: Descriptive text of errors to stderr
|
|
|
*----------------------------------------------------------------------------*/
|
|
|
void S_decode(long code, struct posdata *pdat);
|
|
|
|
|
|
#endif
|
|
|
|
