CLS
PRINT
PRINT "SOLAR INTENSITY"
DIM M(12)
REM ==COMMON CONSTANTS==
P1 = 3.1415926
P2 = .0172021
P3 = 57.295778
REM ==LOAD CALENDAR DATA==
DATA 00,31,28,31,30,31
DATA 30,31,31,30,31,30
FOR J = 1 TO 12
 READ MJ
 M(J)=MJ
NEXT J
[TWTHZE]
PRINT
PRINT
PRINT "INPUT MONTH (1-12)= ";
INPUT " ";M1
PRINT "INPUT DAY (1-31)  = ";
INPUT " ";D
PRINT "INPUT HOUR (0-23) = ";
INPUT " ";H
REM ==CONVERT TO DAY NUMBER==
N = 0
FOR J = 1 TO M1
N = N + M(J)
NEXT J
N = N + D + H / 24
PRINT
PRINT "EASTERN STANDARD  = 5"
PRINT "CENTRAL STANDARD  = 6"
PRINT "MOUNTAIN STANDARD = 7"
PRINT "PACIFIC STANDARD  = 8"
PRINT
PRINT "INPUT TIME ZONE NUMBER = ";
INPUT " ";Z
PRINT
REM ==CALC DECLINATION==
D1 = .406079073
D2 = 1.40446929
D3 = .0132989724
D4 = 1.51396507
D5 = N * P2
R1 = D1 * SIN(D5 -D2) + D3 * (COS(D5 -D4)^2)
A1 = R1 * P3
REM ==EQUATION OF TIME==
T1 = .16797268
T2 = .0520416347
T3 = 19.8500733
T4 = 7.40960196
T5 = N * P2 + T1
T6 = N * P2 -T2
T = -1*T3*SIN(T5)*COS(T5)-T4*SIN(T6)
PRINT "INPUT LATITUDE (DEGREES) =  ";
INPUT " ";L1
PRINT "INPUT LONGITUDE (DEGREES) = ";
INPUT " ";L2
REM ==CALC SUNRISE/SUNSET==
B1= -1*TAN(L1/ P3)*TAN(R1)
B2 = -1*ATN(B1/(-1*B1*B1+1)^.5)+ P1/ 2
B3 = B2 * 12 / P1
B4 = 12-B3-(T/60)-Z+L2/15
B5 = 24-B4
REM==CALC HOUR ANGLE==
H1 = 15*(H-12+Z+(T/60))-L2
H2 = H1 / P3
REM ==ANGLES OF SOLAR BEAM==
F4 = 0
IF ABS(H2) > ABS(B2) GOTO [ONZETHZE]
C1 = COS(L1/P3)
C2 = COS(R1)
C3 = COS(H2)
S1 = SIN(L1/P3)
S2 = SIN(R1)
REM==CALC SOLAR ALTITUDE==
S3 = C1 * C2 * C3 + S1 * S2
R2 = ATN(S3/(-1*S3*S3+1)^.5)
A2 = R2 * P3
REM ==CALC SOLAR AZIMUTH==
C4 = (S3*S1-S2)/(COS(R2)*C1)
R3 = -1*ATN(C4/(-1*C4*C4+1)^.5)+ P1 / 2
A3 = ABS(R3*P3)
IF H1 > 0 GOTO [NIFIZE]
A3 = 180-A3
GOTO [NIEIZE]
[NIFIZE]
A3 = 180+A3
REM ==CALC SOLAR INTENSITY==
[NIEIZE]
F1 = N*.0172142
F2 = 368.4 + 24.538 * COS(F1 -.02431)
F3 = .17167 -.03475 * COS(F1 -.12534)
F4 = F2*EXP(-1*F3/S3)
[ONZETHZE]
REM ===PRINT RESULTS==
PRINT
PRINT
PRINT "DAY NUMBER (1-365)        = ";N
PRINT "TIME OF SUNRISE (HOURS)   =";B4
PRINT "TIME OF SUNSET (HOURS)    = ";B5
PRINT "DECLINATION ANGLE (DEG)   =";A1
PRINT "EQUATION OF TIME(MIN)     =";T
PRINT "SOLAR ALTITUDE (DEGREES)  =";A2
PRINT "SOLAR AZIMUTH (DEGREES)   =";A3
PRINT "SOLAR INTENSITY (BTU/FT^2)= ";F4
PRINT
PRINT "RERUN PROGRAM WITH NEW DATA (Y/N)?  ";
INPUT " ";Q$
IF Q$ = "Y" OR Q$="y" THEN [TWTHZE]
END