-
Notifications
You must be signed in to change notification settings - Fork 0
/
spa.cpp
1178 lines (1005 loc) · 36.5 KB
/
spa.cpp
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
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
//#include <avr/pgmspace.h>
#ifdef ARDUINO_ARCH_AVR
#include <avr/pgmspace.h>
#else
#include <pgmspace.h>
#endif
/////////////////////////////////////////////
// Solar Position Algorithm (SPA) //
// for //
// Solar Radiation Application //
// //
// May 12, 2003 //
// //
// Filename: SPA.C //
// //
// Afshin Michael Andreas //
// Afshin.Andreas@NREL.gov (303)384-6383 //
// //
// Metrology Laboratory //
// Solar Radiation Research Laboratory //
// National Renewable Energy Laboratory //
// 15013 Denver W Pkwy, Golden, CO 80401 //
/////////////////////////////////////////////
/////////////////////////////////////////////
// See the SPA.H header file for usage //
// //
// This code is based on the NREL //
// technical report "Solar Position //
// Algorithm for Solar Radiation //
// Application" by I. Reda & A. Andreas //
/////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////////////////////
//
// NOTICE
// Copyright (C) 2008-2011 Alliance for Sustainable Energy, LLC, All Rights Reserved
//
//The Solar Position Algorithm ("Software") is code in development prepared by employees of the
//Alliance for Sustainable Energy, LLC, (hereinafter the "Contractor"), under Contract No.
//DE-AC36-08GO28308 ("Contract") with the U.S. Department of Energy (the "DOE"). The United
//States Government has been granted for itself and others acting on its behalf a paid-up, non-
//exclusive, irrevocable, worldwide license in the Software to reproduce, prepare derivative
//works, and perform publicly and display publicly. Beginning five (5) years after the date
//permission to assert copyright is obtained from the DOE, and subject to any subsequent five
//(5) year renewals, the United States Government is granted for itself and others acting on
//its behalf a paid-up, non-exclusive, irrevocable, worldwide license in the Software to
//reproduce, prepare derivative works, distribute copies to the public, perform publicly and
//display publicly, and to permit others to do so. If the Contractor ceases to make this
//computer software available, it may be obtained from DOE's Office of Scientific and Technical
//Information's Energy Science and Technology Software Center (ESTSC) at P.O. Box 1020, Oak
//Ridge, TN 37831-1020. THIS SOFTWARE IS PROVIDED BY THE CONTRACTOR "AS IS" AND ANY EXPRESS OR
//IMPLIED WARRANTIES, INCLUDING BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
//AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE CONTRACTOR OR THE
//U.S. GOVERNMENT BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
//WHATSOEVER, INCLUDING BUT NOT LIMITED TO CLAIMS ASSOCIATED WITH THE LOSS OF DATA OR PROFITS,
//WHICH MAY RESULT FROM AN ACTION IN CONTRACT, NEGLIGENCE OR OTHER TORTIOUS CLAIM THAT ARISES
//OUT OF OR IN CONNECTION WITH THE ACCESS, USE OR PERFORMANCE OF THIS SOFTWARE.
//
//The Software is being provided for internal, noncommercial purposes only and shall not be
//re-distributed. Please contact the NREL Commercialization and Technology Transfer Office
//for information concerning a commercial license to use the Software, visit:
//http://midcdmz.nrel.gov/spa/ for the contact information.
//
//As a condition of using the Software in an application, the developer of the application
//agrees to reference the use of the Software and make this Notice readily accessible to any
//end-user in a Help|About screen or equivalent manner.
//
///////////////////////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////////////////////
// Revised 27-FEB-2004 Andreas
// Added bounds check on inputs and return value for spa_calculate().
// Revised 10-MAY-2004 Andreas
// Changed temperature bound check minimum from -273.15 to -273 degrees C.
// Revised 17-JUN-2004 Andreas
// Corrected a problem that caused a bogus sunrise/set/transit on the equinox.
// Revised 18-JUN-2004 Andreas
// Added a "function" input variable that allows the selecting of desired outputs.
// Revised 21-JUN-2004 Andreas
// Added 3 new intermediate output values to SPA structure (srha, ssha, & sta).
// Revised 23-JUN-2004 Andreas
// Enumerations for "function" were renamed and 2 were added.
// Prevented bound checks on inputs that are not used (based on function).
// Revised 01-SEP-2004 Andreas
// Changed a local variable from integer to double.
// Revised 12-JUL-2005 Andreas
// Put a limit on the EOT calculation, so that the result is between -20 and 20.
// Revised 26-OCT-2005 Andreas
// Set the atmos. refraction correction to zero, when sun is below horizon.
// Made atmos_refract input a requirement for all "functions".
// Changed atmos_refract bound check from +/- 10 to +/- 5 degrees.
// Revised 07-NOV-2006 Andreas
// Corrected 3 earth periodic terms in the L_TERMS array.
// Corrected 2 earth periodic terms in the R_TERMS array.
// Revised 10-NOV-2006 Andreas
// Corrected a constant used to calculate topocentric sun declination.
// Put a limit on observer hour angle, so result is between 0 and 360.
// Revised 13-NOV-2006 Andreas
// Corrected calculation of topocentric sun declination.
// Converted all floating point inputs in spa structure to doubles.
// Revised 27-FEB-2007 Andreas
// Minor correction made as to when atmos. refraction correction is set to zero.
// Revised 21-JAN-2008 Andreas
// Minor change to two variable declarations.
// Revised 12-JAN-2009 Andreas
// Changed timezone bound check from +/-12 to +/-18 hours.
// Revised 14-JAN-2009 Andreas
// Corrected a constant used to calculate ecliptic mean obliquity.
// Revised 01-APR-2013 Andreas
// Replace floor with new integer function for tech. report consistency, no affect on results.
// Add "utility" function prototypes to header file for use with NREL's SAMPA.
// Rename 4 "utility" function names (remove "sun") for clarity with NREL's SAMPA.
// Added delta_ut1 as required input, which the fractional second difference between UT and UTC.
// Time must be input w/o delta_ut1 adjustment, instead of assuming adjustment was pre-applied.
// Revised 10-JUL-2014 Andreas
// Change second in spa_data structure from an integer to double to allow fractional second
// Revised 08-SEP-2014 Andreas
// Corrected description of azm_rotation in header file
// Limited azimuth180 to range of 0 to 360 deg (instead of -180 to 180) for tech report consistency
// Changed all variables names from azimuth180 to azimuth_astro
// Renamed 2 "utility" function names for consistency
///////////////////////////////////////////////////////////////////////////////////////////////
#include <math.h>
#include "spa.h"
#define PI 3.1415926535897932384626433832795028841971
#define SUN_RADIUS 0.26667
#define L_COUNT 6
#define B_COUNT 2
#define R_COUNT 5
#define Y_COUNT 63
#define L_MAX_SUBCOUNT 64
#define B_MAX_SUBCOUNT 5
#define R_MAX_SUBCOUNT 40
enum {TERM_A, TERM_B, TERM_C, TERM_COUNT};
enum {TERM_X0, TERM_X1, TERM_X2, TERM_X3, TERM_X4, TERM_X_COUNT};
enum {TERM_PSI_A, TERM_PSI_B, TERM_EPS_C, TERM_EPS_D, TERM_PE_COUNT};
enum {JD_MINUS, JD_ZERO, JD_PLUS, JD_COUNT};
enum {SUN_TRANSIT, SUN_RISE, SUN_SET, SUN_COUNT};
#define TERM_Y_COUNT TERM_X_COUNT
const int l_subcount[L_COUNT] = {64,34,20,7,3,1};
const int b_subcount[B_COUNT] = {5,2};
const int r_subcount[R_COUNT] = {40,10,6,2,1};
///////////////////////////////////////////////////
/// Earth Periodic Terms
///////////////////////////////////////////////////
const double L_TERMS[L_COUNT][L_MAX_SUBCOUNT][TERM_COUNT] =
{
{
{175347046.0,0,0},
{3341656.0,4.6692568,6283.07585},
{34894.0,4.6261,12566.1517},
{3497.0,2.7441,5753.3849},
{3418.0,2.8289,3.5231},
{3136.0,3.6277,77713.7715},
{2676.0,4.4181,7860.4194},
{2343.0,6.1352,3930.2097},
{1324.0,0.7425,11506.7698},
{1273.0,2.0371,529.691},
{1199.0,1.1096,1577.3435},
{990,5.233,5884.927},
{902,2.045,26.298},
{857,3.508,398.149},
{780,1.179,5223.694},
{753,2.533,5507.553},
{505,4.583,18849.228},
{492,4.205,775.523},
{357,2.92,0.067},
{317,5.849,11790.629},
{284,1.899,796.298},
{271,0.315,10977.079},
{243,0.345,5486.778},
{206,4.806,2544.314},
{205,1.869,5573.143},
{202,2.458,6069.777},
{156,0.833,213.299},
{132,3.411,2942.463},
{126,1.083,20.775},
{115,0.645,0.98},
{103,0.636,4694.003},
{102,0.976,15720.839},
{102,4.267,7.114},
{99,6.21,2146.17},
{98,0.68,155.42},
{86,5.98,161000.69},
{85,1.3,6275.96},
{85,3.67,71430.7},
{80,1.81,17260.15},
{79,3.04,12036.46},
{75,1.76,5088.63},
{74,3.5,3154.69},
{74,4.68,801.82},
{70,0.83,9437.76},
{62,3.98,8827.39},
{61,1.82,7084.9},
{57,2.78,6286.6},
{56,4.39,14143.5},
{56,3.47,6279.55},
{52,0.19,12139.55},
{52,1.33,1748.02},
{51,0.28,5856.48},
{49,0.49,1194.45},
{41,5.37,8429.24},
{41,2.4,19651.05},
{39,6.17,10447.39},
{37,6.04,10213.29},
{37,2.57,1059.38},
{36,1.71,2352.87},
{36,1.78,6812.77},
{33,0.59,17789.85},
{30,0.44,83996.85},
{30,2.74,1349.87},
{25,3.16,4690.48}
},
{
{628331966747.0,0,0},
{206059.0,2.678235,6283.07585},
{4303.0,2.6351,12566.1517},
{425.0,1.59,3.523},
{119.0,5.796,26.298},
{109.0,2.966,1577.344},
{93,2.59,18849.23},
{72,1.14,529.69},
{68,1.87,398.15},
{67,4.41,5507.55},
{59,2.89,5223.69},
{56,2.17,155.42},
{45,0.4,796.3},
{36,0.47,775.52},
{29,2.65,7.11},
{21,5.34,0.98},
{19,1.85,5486.78},
{19,4.97,213.3},
{17,2.99,6275.96},
{16,0.03,2544.31},
{16,1.43,2146.17},
{15,1.21,10977.08},
{12,2.83,1748.02},
{12,3.26,5088.63},
{12,5.27,1194.45},
{12,2.08,4694},
{11,0.77,553.57},
{10,1.3,6286.6},
{10,4.24,1349.87},
{9,2.7,242.73},
{9,5.64,951.72},
{8,5.3,2352.87},
{6,2.65,9437.76},
{6,4.67,4690.48}
},
{
{52919.0,0,0},
{8720.0,1.0721,6283.0758},
{309.0,0.867,12566.152},
{27,0.05,3.52},
{16,5.19,26.3},
{16,3.68,155.42},
{10,0.76,18849.23},
{9,2.06,77713.77},
{7,0.83,775.52},
{5,4.66,1577.34},
{4,1.03,7.11},
{4,3.44,5573.14},
{3,5.14,796.3},
{3,6.05,5507.55},
{3,1.19,242.73},
{3,6.12,529.69},
{3,0.31,398.15},
{3,2.28,553.57},
{2,4.38,5223.69},
{2,3.75,0.98}
},
{
{289.0,5.844,6283.076},
{35,0,0},
{17,5.49,12566.15},
{3,5.2,155.42},
{1,4.72,3.52},
{1,5.3,18849.23},
{1,5.97,242.73}
},
{
{114.0,3.142,0},
{8,4.13,6283.08},
{1,3.84,12566.15}
},
{
{1,3.14,0}
}
};
const double B_TERMS[B_COUNT][B_MAX_SUBCOUNT][TERM_COUNT] =
{
{
{280.0,3.199,84334.662},
{102.0,5.422,5507.553},
{80,3.88,5223.69},
{44,3.7,2352.87},
{32,4,1577.34}
},
{
{9,3.9,5507.55},
{6,1.73,5223.69}
}
};
const double R_TERMS[R_COUNT][R_MAX_SUBCOUNT][TERM_COUNT] =
{
{
{100013989.0,0,0},
{1670700.0,3.0984635,6283.07585},
{13956.0,3.05525,12566.1517},
{3084.0,5.1985,77713.7715},
{1628.0,1.1739,5753.3849},
{1576.0,2.8469,7860.4194},
{925.0,5.453,11506.77},
{542.0,4.564,3930.21},
{472.0,3.661,5884.927},
{346.0,0.964,5507.553},
{329.0,5.9,5223.694},
{307.0,0.299,5573.143},
{243.0,4.273,11790.629},
{212.0,5.847,1577.344},
{186.0,5.022,10977.079},
{175.0,3.012,18849.228},
{110.0,5.055,5486.778},
{98,0.89,6069.78},
{86,5.69,15720.84},
{86,1.27,161000.69},
{65,0.27,17260.15},
{63,0.92,529.69},
{57,2.01,83996.85},
{56,5.24,71430.7},
{49,3.25,2544.31},
{47,2.58,775.52},
{45,5.54,9437.76},
{43,6.01,6275.96},
{39,5.36,4694},
{38,2.39,8827.39},
{37,0.83,19651.05},
{37,4.9,12139.55},
{36,1.67,12036.46},
{35,1.84,2942.46},
{33,0.24,7084.9},
{32,0.18,5088.63},
{32,1.78,398.15},
{28,1.21,6286.6},
{28,1.9,6279.55},
{26,4.59,10447.39}
},
{
{103019.0,1.10749,6283.07585},
{1721.0,1.0644,12566.1517},
{702.0,3.142,0},
{32,1.02,18849.23},
{31,2.84,5507.55},
{25,1.32,5223.69},
{18,1.42,1577.34},
{10,5.91,10977.08},
{9,1.42,6275.96},
{9,0.27,5486.78}
},
{
{4359.0,5.7846,6283.0758},
{124.0,5.579,12566.152},
{12,3.14,0},
{9,3.63,77713.77},
{6,1.87,5573.14},
{3,5.47,18849.23}
},
{
{145.0,4.273,6283.076},
{7,3.92,12566.15}
},
{
{4,2.56,6283.08}
}
};
////////////////////////////////////////////////////////////////
/// Periodic Terms for the nutation in longitude and obliquity
////////////////////////////////////////////////////////////////
const int Y_TERMS[Y_COUNT][TERM_Y_COUNT] =
{
{0,0,0,0,1},
{-2,0,0,2,2},
{0,0,0,2,2},
{0,0,0,0,2},
{0,1,0,0,0},
{0,0,1,0,0},
{-2,1,0,2,2},
{0,0,0,2,1},
{0,0,1,2,2},
{-2,-1,0,2,2},
{-2,0,1,0,0},
{-2,0,0,2,1},
{0,0,-1,2,2},
{2,0,0,0,0},
{0,0,1,0,1},
{2,0,-1,2,2},
{0,0,-1,0,1},
{0,0,1,2,1},
{-2,0,2,0,0},
{0,0,-2,2,1},
{2,0,0,2,2},
{0,0,2,2,2},
{0,0,2,0,0},
{-2,0,1,2,2},
{0,0,0,2,0},
{-2,0,0,2,0},
{0,0,-1,2,1},
{0,2,0,0,0},
{2,0,-1,0,1},
{-2,2,0,2,2},
{0,1,0,0,1},
{-2,0,1,0,1},
{0,-1,0,0,1},
{0,0,2,-2,0},
{2,0,-1,2,1},
{2,0,1,2,2},
{0,1,0,2,2},
{-2,1,1,0,0},
{0,-1,0,2,2},
{2,0,0,2,1},
{2,0,1,0,0},
{-2,0,2,2,2},
{-2,0,1,2,1},
{2,0,-2,0,1},
{2,0,0,0,1},
{0,-1,1,0,0},
{-2,-1,0,2,1},
{-2,0,0,0,1},
{0,0,2,2,1},
{-2,0,2,0,1},
{-2,1,0,2,1},
{0,0,1,-2,0},
{-1,0,1,0,0},
{-2,1,0,0,0},
{1,0,0,0,0},
{0,0,1,2,0},
{0,0,-2,2,2},
{-1,-1,1,0,0},
{0,1,1,0,0},
{0,-1,1,2,2},
{2,-1,-1,2,2},
{0,0,3,2,2},
{2,-1,0,2,2},
};
const double PE_TERMS[Y_COUNT][TERM_PE_COUNT] ={
{-171996,-174.2,92025,8.9},
{-13187,-1.6,5736,-3.1},
{-2274,-0.2,977,-0.5},
{2062,0.2,-895,0.5},
{1426,-3.4,54,-0.1},
{712,0.1,-7,0},
{-517,1.2,224,-0.6},
{-386,-0.4,200,0},
{-301,0,129,-0.1},
{217,-0.5,-95,0.3},
{-158,0,0,0},
{129,0.1,-70,0},
{123,0,-53,0},
{63,0,0,0},
{63,0.1,-33,0},
{-59,0,26,0},
{-58,-0.1,32,0},
{-51,0,27,0},
{48,0,0,0},
{46,0,-24,0},
{-38,0,16,0},
{-31,0,13,0},
{29,0,0,0},
{29,0,-12,0},
{26,0,0,0},
{-22,0,0,0},
{21,0,-10,0},
{17,-0.1,0,0},
{16,0,-8,0},
{-16,0.1,7,0},
{-15,0,9,0},
{-13,0,7,0},
{-12,0,6,0},
{11,0,0,0},
{-10,0,5,0},
{-8,0,3,0},
{7,0,-3,0},
{-7,0,0,0},
{-7,0,3,0},
{-7,0,3,0},
{6,0,0,0},
{6,0,-3,0},
{6,0,-3,0},
{-6,0,3,0},
{-6,0,3,0},
{5,0,0,0},
{-5,0,3,0},
{-5,0,3,0},
{-5,0,3,0},
{4,0,0,0},
{4,0,0,0},
{4,0,0,0},
{-4,0,0,0},
{-4,0,0,0},
{-4,0,0,0},
{3,0,0,0},
{-3,0,0,0},
{-3,0,0,0},
{-3,0,0,0},
{-3,0,0,0},
{-3,0,0,0},
{-3,0,0,0},
{-3,0,0,0},
};
///////////////////////////////////////////////
double rad2deg(double radians)
{
return (180.0/PI)*radians;
}
double deg2rad(double degrees)
{
return (PI/180.0)*degrees;
}
int integer(double value)
{
return value;
}
double limit_degrees(double degrees)
{
double limited;
degrees /= 360.0;
limited = 360.0*(degrees-floor(degrees));
if (limited < 0) limited += 360.0;
return limited;
}
double limit_degrees180pm(double degrees)
{
double limited;
degrees /= 360.0;
limited = 360.0*(degrees-floor(degrees));
if (limited < -180.0) limited += 360.0;
else if (limited > 180.0) limited -= 360.0;
return limited;
}
double limit_degrees180(double degrees)
{
double limited;
degrees /= 180.0;
limited = 180.0*(degrees-floor(degrees));
if (limited < 0) limited += 180.0;
return limited;
}
double limit_zero2one(double value)
{
double limited;
limited = value - floor(value);
if (limited < 0) limited += 1.0;
return limited;
}
double limit_minutes(double minutes)
{
double limited=minutes;
if (limited < -20.0) limited += 1440.0;
else if (limited > 20.0) limited -= 1440.0;
return limited;
}
double dayfrac_to_local_hr(double dayfrac, double timezone)
{
return 24.0*limit_zero2one(dayfrac + timezone/24.0);
}
double third_order_polynomial(double a, double b, double c, double d, double x)
{
return ((a*x + b)*x + c)*x + d;
}
///////////////////////////////////////////////////////////////////////////////////////////////
int validate_inputs(spa_data *spa)
{
if ((spa->year < -2000) || (spa->year > 6000)) return 1;
if ((spa->month < 1 ) || (spa->month > 12 )) return 2;
if ((spa->day < 1 ) || (spa->day > 31 )) return 3;
if ((spa->hour < 0 ) || (spa->hour > 24 )) return 4;
if ((spa->minute < 0 ) || (spa->minute > 59 )) return 5;
if ((spa->second < 0 ) || (spa->second >=60 )) return 6;
if ((spa->pressure < 0 ) || (spa->pressure > 5000)) return 12;
if ((spa->temperature <= -273) || (spa->temperature > 6000)) return 13;
if ((spa->delta_ut1 <= -1 ) || (spa->delta_ut1 >= 1 )) return 17;
if ((spa->hour == 24 ) && (spa->minute > 0 )) return 5;
if ((spa->hour == 24 ) && (spa->second > 0 )) return 6;
if (fabs(spa->delta_t) > 8000 ) return 7;
if (fabs(spa->timezone) > 18 ) return 8;
if (fabs(spa->longitude) > 180 ) return 9;
if (fabs(spa->latitude) > 90 ) return 10;
if (fabs(spa->atmos_refract) > 5 ) return 16;
if ( spa->elevation < -6500000) return 11;
if ((spa->function == SPA_ZA_INC) || (spa->function == SPA_ALL))
{
if (fabs(spa->slope) > 360) return 14;
if (fabs(spa->azm_rotation) > 360) return 15;
}
return 0;
}
///////////////////////////////////////////////////////////////////////////////////////////////
double julian_day (int year, int month, int day, int hour, int minute, double second, double dut1, double tz)
{
double day_decimal, julian_day, a;
day_decimal = day + (hour - tz + (minute + (second + dut1)/60.0)/60.0)/24.0;
if (month < 3) {
month += 12;
year--;
}
julian_day = integer(365.25*(year+4716.0)) + integer(30.6001*(month+1)) + day_decimal - 1524.5;
if (julian_day > 2299160.0) {
a = integer(year/100);
julian_day += (2 - a + integer(a/4));
}
return julian_day;
}
double julian_century(double jd)
{
return (jd-2451545.0)/36525.0;
}
double julian_ephemeris_day(double jd, double delta_t)
{
return jd+delta_t/86400.0;
}
double julian_ephemeris_century(double jde)
{
return (jde - 2451545.0)/36525.0;
}
double julian_ephemeris_millennium(double jce)
{
return (jce/10.0);
}
double earth_periodic_term_summation(const double terms[][TERM_COUNT], int count, double jme)
{
int i;
double sum=0;
for (i = 0; i < count; i++)
sum += terms[i][TERM_A]*cos(terms[i][TERM_B]+terms[i][TERM_C]*jme);
return sum;
}
double earth_values(double term_sum[], int count, double jme)
{
int i;
double sum=0;
for (i = 0; i < count; i++)
sum += term_sum[i]*pow(jme, i);
sum /= 1.0e8;
return sum;
}
double earth_heliocentric_longitude(double jme)
{
double sum[L_COUNT];
int i;
for (i = 0; i < L_COUNT; i++)
sum[i] = earth_periodic_term_summation(L_TERMS[i], l_subcount[i], jme);
return limit_degrees(rad2deg(earth_values(sum, L_COUNT, jme)));
}
double earth_heliocentric_latitude(double jme)
{
double sum[B_COUNT];
int i;
for (i = 0; i < B_COUNT; i++)
sum[i] = earth_periodic_term_summation(B_TERMS[i], b_subcount[i], jme);
return rad2deg(earth_values(sum, B_COUNT, jme));
}
double earth_radius_vector(double jme)
{
double sum[R_COUNT];
int i;
for (i = 0; i < R_COUNT; i++)
sum[i] = earth_periodic_term_summation(R_TERMS[i], r_subcount[i], jme);
return earth_values(sum, R_COUNT, jme);
}
double geocentric_longitude(double l)
{
double theta = l + 180.0;
if (theta >= 360.0) theta -= 360.0;
return theta;
}
double geocentric_latitude(double b)
{
return -b;
}
double mean_elongation_moon_sun(double jce)
{
return third_order_polynomial(1.0/189474.0, -0.0019142, 445267.11148, 297.85036, jce);
}
double mean_anomaly_sun(double jce)
{
return third_order_polynomial(-1.0/300000.0, -0.0001603, 35999.05034, 357.52772, jce);
}
double mean_anomaly_moon(double jce)
{
return third_order_polynomial(1.0/56250.0, 0.0086972, 477198.867398, 134.96298, jce);
}
double argument_latitude_moon(double jce)
{
return third_order_polynomial(1.0/327270.0, -0.0036825, 483202.017538, 93.27191, jce);
}
double ascending_longitude_moon(double jce)
{
return third_order_polynomial(1.0/450000.0, 0.0020708, -1934.136261, 125.04452, jce);
}
double xy_term_summation(int i, double x[TERM_X_COUNT])
{
int j;
double sum=0;
for (j = 0; j < TERM_Y_COUNT; j++)
sum += x[j]*Y_TERMS[i][j];
return sum;
}
void nutation_longitude_and_obliquity(double jce, double x[TERM_X_COUNT], double *del_psi,
double *del_epsilon)
{
int i;
double xy_term_sum, sum_psi=0, sum_epsilon=0;
for (i = 0; i < Y_COUNT; i++) {
xy_term_sum = deg2rad(xy_term_summation(i, x));
sum_psi += (PE_TERMS[i][TERM_PSI_A] + jce*PE_TERMS[i][TERM_PSI_B])*sin(xy_term_sum);
sum_epsilon += (PE_TERMS[i][TERM_EPS_C] + jce*PE_TERMS[i][TERM_EPS_D])*cos(xy_term_sum);
}
*del_psi = sum_psi / 36000000.0;
*del_epsilon = sum_epsilon / 36000000.0;
}
double ecliptic_mean_obliquity(double jme)
{
double u = jme/10.0;
return 84381.448 + u*(-4680.93 + u*(-1.55 + u*(1999.25 + u*(-51.38 + u*(-249.67 +
u*( -39.05 + u*( 7.12 + u*( 27.87 + u*( 5.79 + u*2.45)))))))));
}
double ecliptic_true_obliquity(double delta_epsilon, double epsilon0)
{
return delta_epsilon + epsilon0/3600.0;
}
double aberration_correction(double r)
{
return -20.4898 / (3600.0*r);
}
double apparent_sun_longitude(double theta, double delta_psi, double delta_tau)
{
return theta + delta_psi + delta_tau;
}
double greenwich_mean_sidereal_time (double jd, double jc)
{
return limit_degrees(280.46061837 + 360.98564736629 * (jd - 2451545.0) +
jc*jc*(0.000387933 - jc/38710000.0));
}
double greenwich_sidereal_time (double nu0, double delta_psi, double epsilon)
{
return nu0 + delta_psi*cos(deg2rad(epsilon));
}
double geocentric_right_ascension(double lamda, double epsilon, double beta)
{
double lamda_rad = deg2rad(lamda);
double epsilon_rad = deg2rad(epsilon);
return limit_degrees(rad2deg(atan2(sin(lamda_rad)*cos(epsilon_rad) -
tan(deg2rad(beta))*sin(epsilon_rad), cos(lamda_rad))));
}
double geocentric_declination(double beta, double epsilon, double lamda)
{
double beta_rad = deg2rad(beta);
double epsilon_rad = deg2rad(epsilon);
return rad2deg(asin(sin(beta_rad)*cos(epsilon_rad) +
cos(beta_rad)*sin(epsilon_rad)*sin(deg2rad(lamda))));
}
double observer_hour_angle(double nu, double longitude, double alpha_deg)
{
return limit_degrees(nu + longitude - alpha_deg);
}
double sun_equatorial_horizontal_parallax(double r)
{
return 8.794 / (3600.0 * r);
}
void right_ascension_parallax_and_topocentric_dec(double latitude, double elevation,
double xi, double h, double delta, double *delta_alpha, double *delta_prime)
{
double delta_alpha_rad;
double lat_rad = deg2rad(latitude);
double xi_rad = deg2rad(xi);
double h_rad = deg2rad(h);
double delta_rad = deg2rad(delta);
double u = atan(0.99664719 * tan(lat_rad));
double y = 0.99664719 * sin(u) + elevation*sin(lat_rad)/6378140.0;
double x = cos(u) + elevation*cos(lat_rad)/6378140.0;
delta_alpha_rad = atan2( - x*sin(xi_rad) *sin(h_rad),
cos(delta_rad) - x*sin(xi_rad) *cos(h_rad));
*delta_prime = rad2deg(atan2((sin(delta_rad) - y*sin(xi_rad))*cos(delta_alpha_rad),
cos(delta_rad) - x*sin(xi_rad) *cos(h_rad)));
*delta_alpha = rad2deg(delta_alpha_rad);
}
double topocentric_right_ascension(double alpha_deg, double delta_alpha)
{
return alpha_deg + delta_alpha;
}
double topocentric_local_hour_angle(double h, double delta_alpha)
{
return h - delta_alpha;
}
double topocentric_elevation_angle(double latitude, double delta_prime, double h_prime)
{
double lat_rad = deg2rad(latitude);
double delta_prime_rad = deg2rad(delta_prime);
return rad2deg(asin(sin(lat_rad)*sin(delta_prime_rad) +
cos(lat_rad)*cos(delta_prime_rad) * cos(deg2rad(h_prime))));
}
double atmospheric_refraction_correction(double pressure, double temperature,
double atmos_refract, double e0)
{
double del_e = 0;
if (e0 >= -1*(SUN_RADIUS + atmos_refract))
del_e = (pressure / 1010.0) * (283.0 / (273.0 + temperature)) *
1.02 / (60.0 * tan(deg2rad(e0 + 10.3/(e0 + 5.11))));
return del_e;
}
double topocentric_elevation_angle_corrected(double e0, double delta_e)
{
return e0 + delta_e;
}
double topocentric_zenith_angle(double e)
{
return 90.0 - e;
}
double topocentric_azimuth_angle_astro(double h_prime, double latitude, double delta_prime)
{
double h_prime_rad = deg2rad(h_prime);
double lat_rad = deg2rad(latitude);
return limit_degrees(rad2deg(atan2(sin(h_prime_rad),
cos(h_prime_rad)*sin(lat_rad) - tan(deg2rad(delta_prime))*cos(lat_rad))));
}
double topocentric_azimuth_angle(double azimuth_astro)
{
return limit_degrees(azimuth_astro + 180.0);
}
double surface_incidence_angle(double zenith, double azimuth_astro, double azm_rotation,
double slope)
{
double zenith_rad = deg2rad(zenith);
double slope_rad = deg2rad(slope);
return rad2deg(acos(cos(zenith_rad)*cos(slope_rad) +
sin(slope_rad )*sin(zenith_rad) * cos(deg2rad(azimuth_astro - azm_rotation))));
}
double sun_mean_longitude(double jme)
{
return limit_degrees(280.4664567 + jme*(360007.6982779 + jme*(0.03032028 +
jme*(1/49931.0 + jme*(-1/15300.0 + jme*(-1/2000000.0))))));
}
double eot(double m, double alpha, double del_psi, double epsilon)
{
return limit_minutes(4.0*(m - 0.0057183 - alpha + del_psi*cos(deg2rad(epsilon))));
}
double approx_sun_transit_time(double alpha_zero, double longitude, double nu)
{
return (alpha_zero - longitude - nu) / 360.0;
}
double sun_hour_angle_at_rise_set(double latitude, double delta_zero, double h0_prime)
{
double h0 = -99999;
double latitude_rad = deg2rad(latitude);
double delta_zero_rad = deg2rad(delta_zero);
double argument = (sin(deg2rad(h0_prime)) - sin(latitude_rad)*sin(delta_zero_rad)) /
(cos(latitude_rad)*cos(delta_zero_rad));
if (fabs(argument) <= 1) h0 = limit_degrees180(rad2deg(acos(argument)));
return h0;
}
void approx_sun_rise_and_set(double *m_rts, double h0)
{
double h0_dfrac = h0/360.0;
m_rts[SUN_RISE] = limit_zero2one(m_rts[SUN_TRANSIT] - h0_dfrac);
m_rts[SUN_SET] = limit_zero2one(m_rts[SUN_TRANSIT] + h0_dfrac);
m_rts[SUN_TRANSIT] = limit_zero2one(m_rts[SUN_TRANSIT]);
}
double rts_alpha_delta_prime(double *ad, double n)
{
double a = ad[JD_ZERO] - ad[JD_MINUS];
double b = ad[JD_PLUS] - ad[JD_ZERO];
if (fabs(a) >= 2.0) a = limit_zero2one(a);
if (fabs(b) >= 2.0) b = limit_zero2one(b);
return ad[JD_ZERO] + n * (a + b + (b-a)*n)/2.0;
}