home *** CD-ROM | disk | FTP | other *** search
- {*
- * SOLAR CALCULATIONS
- *
- * 7/25/84
- * 10/10/86
- *
- *}
-
- RLAT = 0.66; {* Site latitude (radians) *}
-
- RLON = 2.13; {* Site longitude (radians) *}
-
- RSM = 120 * PI/180; {* Standard meridian (radians) *}
-
-
- stadj(jd) {* solar time adjustment (hours) *}
- { jd is days into year }
- =
- 0.170 * sin( 4*PI/373 * (jd - 80) ) -
- 0.129 * sin( 2*PI/355 * (jd - 8 ) ) +
- 12*(RSM-RLON)/PI
- ;
-
-
- sdec(jd) {* solar declination angle (radians) *}
- { jd is days into year }
- =
- 0.4093 * sin( 2*PI/368 * (jd - 81) )
- ;
-
-
- salt(sd, st) {* solar altitude (radians) *}
- { sd is solar declination, st is solar time (hours) }
- =
- asin( sin(RLAT) * sin(sd) - cos(RLAT) * cos(sd) *
- cos(st*PI/12) )
- ;
-
-
- sazi(sd, st) {* the solar azimuth (radians) *}
- { sd is solar declination, st is solar time (hours) }
- =
- -atan2( cos(sd) * sin(st*PI/12),
- -cos(RLAT)*sin(sd) -
- sin(RLAT)*cos(sd)*cos(st*PI/12) )
- ;
-
-
- SAZI = sazi(SDEC, STIME) * 180/PI;
-
- SALT = salt(SDEC, STIME) * 180/PI;
-
- SDEC = sdec(JDATE);
-
- STIME = TIME + stadj(JDATE);
-
- JDATE = DAY + select(MONTH,0,31,59,90,120,151,181,212,243,273,304,334);
-