-
Notifications
You must be signed in to change notification settings - Fork 7
/
gpssim.c
2364 lines (1953 loc) · 57.5 KB
/
gpssim.c
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
#define _CRT_SECURE_NO_DEPRECATE
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <time.h>
#ifdef _WIN32
#include "getopt.h"
#else
#include <unistd.h>
#endif
#include "gpssim.h"
int sinTable512[] = {
2, 5, 8, 11, 14, 17, 20, 23, 26, 29, 32, 35, 38, 41, 44, 47,
50, 53, 56, 59, 62, 65, 68, 71, 74, 77, 80, 83, 86, 89, 91, 94,
97, 100, 103, 105, 108, 111, 114, 116, 119, 122, 125, 127, 130, 132, 135, 138,
140, 143, 145, 148, 150, 153, 155, 157, 160, 162, 164, 167, 169, 171, 173, 176,
178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 205, 207,
209, 210, 212, 214, 215, 217, 218, 220, 221, 223, 224, 225, 227, 228, 229, 230,
232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 241, 242, 243, 244, 244, 245,
245, 246, 247, 247, 248, 248, 248, 249, 249, 249, 249, 250, 250, 250, 250, 250,
250, 250, 250, 250, 250, 249, 249, 249, 249, 248, 248, 248, 247, 247, 246, 245,
245, 244, 244, 243, 242, 241, 241, 240, 239, 238, 237, 236, 235, 234, 233, 232,
230, 229, 228, 227, 225, 224, 223, 221, 220, 218, 217, 215, 214, 212, 210, 209,
207, 205, 204, 202, 200, 198, 196, 194, 192, 190, 188, 186, 184, 182, 180, 178,
176, 173, 171, 169, 167, 164, 162, 160, 157, 155, 153, 150, 148, 145, 143, 140,
138, 135, 132, 130, 127, 125, 122, 119, 116, 114, 111, 108, 105, 103, 100, 97,
94, 91, 89, 86, 83, 80, 77, 74, 71, 68, 65, 62, 59, 56, 53, 50,
47, 44, 41, 38, 35, 32, 29, 26, 23, 20, 17, 14, 11, 8, 5, 2,
-2, -5, -8, -11, -14, -17, -20, -23, -26, -29, -32, -35, -38, -41, -44, -47,
-50, -53, -56, -59, -62, -65, -68, -71, -74, -77, -80, -83, -86, -89, -91, -94,
-97,-100,-103,-105,-108,-111,-114,-116,-119,-122,-125,-127,-130,-132,-135,-138,
-140,-143,-145,-148,-150,-153,-155,-157,-160,-162,-164,-167,-169,-171,-173,-176,
-178,-180,-182,-184,-186,-188,-190,-192,-194,-196,-198,-200,-202,-204,-205,-207,
-209,-210,-212,-214,-215,-217,-218,-220,-221,-223,-224,-225,-227,-228,-229,-230,
-232,-233,-234,-235,-236,-237,-238,-239,-240,-241,-241,-242,-243,-244,-244,-245,
-245,-246,-247,-247,-248,-248,-248,-249,-249,-249,-249,-250,-250,-250,-250,-250,
-250,-250,-250,-250,-250,-249,-249,-249,-249,-248,-248,-248,-247,-247,-246,-245,
-245,-244,-244,-243,-242,-241,-241,-240,-239,-238,-237,-236,-235,-234,-233,-232,
-230,-229,-228,-227,-225,-224,-223,-221,-220,-218,-217,-215,-214,-212,-210,-209,
-207,-205,-204,-202,-200,-198,-196,-194,-192,-190,-188,-186,-184,-182,-180,-178,
-176,-173,-171,-169,-167,-164,-162,-160,-157,-155,-153,-150,-148,-145,-143,-140,
-138,-135,-132,-130,-127,-125,-122,-119,-116,-114,-111,-108,-105,-103,-100, -97,
-94, -91, -89, -86, -83, -80, -77, -74, -71, -68, -65, -62, -59, -56, -53, -50,
-47, -44, -41, -38, -35, -32, -29, -26, -23, -20, -17, -14, -11, -8, -5, -2
};
int cosTable512[] = {
250, 250, 250, 250, 250, 249, 249, 249, 249, 248, 248, 248, 247, 247, 246, 245,
245, 244, 244, 243, 242, 241, 241, 240, 239, 238, 237, 236, 235, 234, 233, 232,
230, 229, 228, 227, 225, 224, 223, 221, 220, 218, 217, 215, 214, 212, 210, 209,
207, 205, 204, 202, 200, 198, 196, 194, 192, 190, 188, 186, 184, 182, 180, 178,
176, 173, 171, 169, 167, 164, 162, 160, 157, 155, 153, 150, 148, 145, 143, 140,
138, 135, 132, 130, 127, 125, 122, 119, 116, 114, 111, 108, 105, 103, 100, 97,
94, 91, 89, 86, 83, 80, 77, 74, 71, 68, 65, 62, 59, 56, 53, 50,
47, 44, 41, 38, 35, 32, 29, 26, 23, 20, 17, 14, 11, 8, 5, 2,
-2, -5, -8, -11, -14, -17, -20, -23, -26, -29, -32, -35, -38, -41, -44, -47,
-50, -53, -56, -59, -62, -65, -68, -71, -74, -77, -80, -83, -86, -89, -91, -94,
-97,-100,-103,-105,-108,-111,-114,-116,-119,-122,-125,-127,-130,-132,-135,-138,
-140,-143,-145,-148,-150,-153,-155,-157,-160,-162,-164,-167,-169,-171,-173,-176,
-178,-180,-182,-184,-186,-188,-190,-192,-194,-196,-198,-200,-202,-204,-205,-207,
-209,-210,-212,-214,-215,-217,-218,-220,-221,-223,-224,-225,-227,-228,-229,-230,
-232,-233,-234,-235,-236,-237,-238,-239,-240,-241,-241,-242,-243,-244,-244,-245,
-245,-246,-247,-247,-248,-248,-248,-249,-249,-249,-249,-250,-250,-250,-250,-250,
-250,-250,-250,-250,-250,-249,-249,-249,-249,-248,-248,-248,-247,-247,-246,-245,
-245,-244,-244,-243,-242,-241,-241,-240,-239,-238,-237,-236,-235,-234,-233,-232,
-230,-229,-228,-227,-225,-224,-223,-221,-220,-218,-217,-215,-214,-212,-210,-209,
-207,-205,-204,-202,-200,-198,-196,-194,-192,-190,-188,-186,-184,-182,-180,-178,
-176,-173,-171,-169,-167,-164,-162,-160,-157,-155,-153,-150,-148,-145,-143,-140,
-138,-135,-132,-130,-127,-125,-122,-119,-116,-114,-111,-108,-105,-103,-100, -97,
-94, -91, -89, -86, -83, -80, -77, -74, -71, -68, -65, -62, -59, -56, -53, -50,
-47, -44, -41, -38, -35, -32, -29, -26, -23, -20, -17, -14, -11, -8, -5, -2,
2, 5, 8, 11, 14, 17, 20, 23, 26, 29, 32, 35, 38, 41, 44, 47,
50, 53, 56, 59, 62, 65, 68, 71, 74, 77, 80, 83, 86, 89, 91, 94,
97, 100, 103, 105, 108, 111, 114, 116, 119, 122, 125, 127, 130, 132, 135, 138,
140, 143, 145, 148, 150, 153, 155, 157, 160, 162, 164, 167, 169, 171, 173, 176,
178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 205, 207,
209, 210, 212, 214, 215, 217, 218, 220, 221, 223, 224, 225, 227, 228, 229, 230,
232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 241, 242, 243, 244, 244, 245,
245, 246, 247, 247, 248, 248, 248, 249, 249, 249, 249, 250, 250, 250, 250, 250
};
// Receiver antenna attenuation in dB for boresight angle = 0:5:180 [deg]
double ant_pat_db[37] = {
0.00, 0.00, 0.22, 0.44, 0.67, 1.11, 1.56, 2.00, 2.44, 2.89, 3.56, 4.22,
4.89, 5.56, 6.22, 6.89, 7.56, 8.22, 8.89, 9.78, 10.67, 11.56, 12.44, 13.33,
14.44, 15.56, 16.67, 17.78, 18.89, 20.00, 21.33, 22.67, 24.00, 25.56, 27.33, 29.33,
31.56
};
int allocatedSat[MAX_SAT];
/*! \brief Subtract two vectors of double
* \param[out] y Result of subtraction
* \param[in] x1 Minuend of subtracion
* \param[in] x2 Subtrahend of subtracion
*/
void subVect(double *y, const double *x1, const double *x2)
{
y[0] = x1[0]-x2[0];
y[1] = x1[1]-x2[1];
y[2] = x1[2]-x2[2];
return;
}
/*! \brief Compute Norm of Vector
* \param[in] x Input vector
* \returns Length (Norm) of the input vector
*/
double normVect(const double *x)
{
return(sqrt(x[0]*x[0]+x[1]*x[1]+x[2]*x[2]));
}
/*! \brief Compute dot-product of two vectors
* \param[in] x1 First multiplicand
* \param[in] x2 Second multiplicand
* \returns Dot-product of both multiplicands
*/
double dotProd(const double *x1, const double *x2)
{
return(x1[0]*x2[0]+x1[1]*x2[1]+x1[2]*x2[2]);
}
/* !\brief generate the C/A code sequence for a given Satellite Vehicle PRN
* \param[in] prn PRN nuber of the Satellite Vehicle
* \param[out] ca Caller-allocated integer array of 1023 bytes
*/
void codegen(int *ca, int prn)
{
int delay[] = {
5, 6, 7, 8, 17, 18, 139, 140, 141, 251,
252, 254, 255, 256, 257, 258, 469, 470, 471, 472,
473, 474, 509, 512, 513, 514, 515, 516, 859, 860,
861, 862};
int g1[CA_SEQ_LEN], g2[CA_SEQ_LEN];
int r1[N_DWRD_SBF], r2[N_DWRD_SBF];
int c1, c2;
int i,j;
if (prn<1 || prn>32)
return;
for (i=0; i<N_DWRD_SBF; i++)
r1[i] = r2[i] = -1;
for (i=0; i<CA_SEQ_LEN; i++)
{
g1[i] = r1[9];
g2[i] = r2[9];
c1 = r1[2]*r1[9];
c2 = r2[1]*r2[2]*r2[5]*r2[7]*r2[8]*r2[9];
for (j=9; j>0; j--)
{
r1[j] = r1[j-1];
r2[j] = r2[j-1];
}
r1[0] = c1;
r2[0] = c2;
}
for (i=0,j=CA_SEQ_LEN-delay[prn-1]; i<CA_SEQ_LEN; i++,j++)
ca[i] = (1-g1[i]*g2[j%CA_SEQ_LEN])/2;
return;
}
/*! \brief Convert a UTC date into a GPS date
* \param[in] t input date in UTC form
* \param[out] g output date in GPS form
*/
void date2gps(const datetime_t *t, gpstime_t *g)
{
int doy[12] = {0,31,59,90,120,151,181,212,243,273,304,334};
int ye;
int de;
int lpdays;
ye = t->y - 1980;
// Compute the number of leap days since Jan 5/Jan 6, 1980.
lpdays = ye/4 + 1;
if ((ye%4)==0 && t->m<=2)
lpdays--;
// Compute the number of days elapsed since Jan 5/Jan 6, 1980.
de = ye*365 + doy[t->m-1] + t->d + lpdays - 6;
// Convert time to GPS weeks and seconds.
g->week = de / 7;
g->sec = (double)(de%7)*SECONDS_IN_DAY + t->hh*SECONDS_IN_HOUR
+ t->mm*SECONDS_IN_MINUTE + t->sec;
return;
}
void gps2date(const gpstime_t *g, datetime_t *t)
{
// Convert Julian day number to calendar date
int c = (int)(7*g->week + floor(g->sec/86400.0)+2444245.0) + 1537;
int d = (int)((c-122.1)/365.25);
int e = 365*d + d/4;
int f = (int)((c-e)/30.6001);
t->d = c - e - (int)(30.6001*f);
t->m = f - 1 - 12*(f/14);
t->y = d - 4715 - ((7 + t->m)/10);
t->hh = ((int)(g->sec/3600.0))%24;
t->mm = ((int)(g->sec/60.0))%60;
t->sec = g->sec - 60.0*floor(g->sec/60.0);
return;
}
/*! \brief Convert Earth-centered Earth-fixed (ECEF) into Lat/Long/Heighth
* \param[in] xyz Input Array of X, Y and Z ECEF coordinates
* \param[out] llh Output Array of Latitude, Longitude and Height
*/
void xyz2llh(const double *xyz, double *llh)
{
double a,eps,e,e2;
double x,y,z;
double rho2,dz,zdz,nh,slat,n,dz_new;
a = WGS84_RADIUS;
e = WGS84_ECCENTRICITY;
eps = 1.0e-3;
e2 = e*e;
if (normVect(xyz)<eps)
{
// Invalid ECEF vector
llh[0] = 0.0;
llh[1] = 0.0;
llh[2] = -a;
return;
}
x = xyz[0];
y = xyz[1];
z = xyz[2];
rho2 = x*x + y*y;
dz = e2*z;
while (1)
{
zdz = z + dz;
nh = sqrt(rho2 + zdz*zdz);
slat = zdz / nh;
n = a / sqrt(1.0-e2*slat*slat);
dz_new = n*e2*slat;
if (fabs(dz-dz_new) < eps)
break;
dz = dz_new;
}
llh[0] = atan2(zdz, sqrt(rho2));
llh[1] = atan2(y, x);
llh[2] = nh - n;
return;
}
/*! \brief Convert Lat/Long/Height into Earth-centered Earth-fixed (ECEF)
* \param[in] llh Input Array of Latitude, Longitude and Height
* \param[out] xyz Output Array of X, Y and Z ECEF coordinates
*/
void llh2xyz(const double *llh, double *xyz)
{
double n;
double a;
double e;
double e2;
double clat;
double slat;
double clon;
double slon;
double d,nph;
double tmp;
a = WGS84_RADIUS;
e = WGS84_ECCENTRICITY;
e2 = e*e;
clat = cos(llh[0]);
slat = sin(llh[0]);
clon = cos(llh[1]);
slon = sin(llh[1]);
d = e*slat;
n = a/sqrt(1.0-d*d);
nph = n + llh[2];
tmp = nph*clat;
xyz[0] = tmp*clon;
xyz[1] = tmp*slon;
xyz[2] = ((1.0-e2)*n + llh[2])*slat;
return;
}
/*! \brief Compute the intermediate matrix for LLH to ECEF
* \param[in] llh Input position in Latitude-Longitude-Height format
* \param[out] t Three-by-Three output matrix
*/
void ltcmat(const double *llh, double t[3][3])
{
double slat, clat;
double slon, clon;
slat = sin(llh[0]);
clat = cos(llh[0]);
slon = sin(llh[1]);
clon = cos(llh[1]);
t[0][0] = -slat*clon;
t[0][1] = -slat*slon;
t[0][2] = clat;
t[1][0] = -slon;
t[1][1] = clon;
t[1][2] = 0.0;
t[2][0] = clat*clon;
t[2][1] = clat*slon;
t[2][2] = slat;
return;
}
/*! \brief Convert Earth-centered Earth-Fixed to ?
* \param[in] xyz Input position as vector in ECEF format
* \param[in] t Intermediate matrix computed by \ref ltcmat
* \param[out] neu Output position as North-East-Up format
*/
void ecef2neu(const double *xyz, double t[3][3], double *neu)
{
neu[0] = t[0][0]*xyz[0] + t[0][1]*xyz[1] + t[0][2]*xyz[2];
neu[1] = t[1][0]*xyz[0] + t[1][1]*xyz[1] + t[1][2]*xyz[2];
neu[2] = t[2][0]*xyz[0] + t[2][1]*xyz[1] + t[2][2]*xyz[2];
return;
}
/*! \brief Convert North-Eeast-Up to Azimuth + Elevation
* \param[in] neu Input position in North-East-Up format
* \param[out] azel Output array of azimuth + elevation as double
*/
void neu2azel(double *azel, const double *neu)
{
double ne;
azel[0] = atan2(neu[1],neu[0]);
if (azel[0]<0.0)
azel[0] += (2.0*PI);
ne = sqrt(neu[0]*neu[0] + neu[1]*neu[1]);
azel[1] = atan2(neu[2], ne);
return;
}
/*! \brief Compute Satellite position, velocity and clock at given time
* \param[in] eph Ephemeris data of the satellite
* \param[in] g GPS time at which position is to be computed
* \param[out] pos Computed position (vector)
* \param[out] vel Computed velociy (vector)
* \param[clk] clk Computed clock
*/
void satpos(ephem_t eph, gpstime_t g, double *pos, double *vel, double *clk)
{
// Computing Satellite Velocity using the Broadcast Ephemeris
// http://www.ngs.noaa.gov/gps-toolbox/bc_velo.htm
double tk;
double mk;
double ek;
double ekold;
double ekdot;
double cek,sek;
double pk;
double pkdot;
double c2pk,s2pk;
double uk;
double ukdot;
double cuk,suk;
double ok;
double sok,cok;
double ik;
double ikdot;
double sik,cik;
double rk;
double rkdot;
double xpk,ypk;
double xpkdot,ypkdot;
double relativistic, OneMinusecosE, tmp;
tk = g.sec - eph.toe.sec;
if(tk>SECONDS_IN_HALF_WEEK)
tk -= SECONDS_IN_WEEK;
else if(tk<-SECONDS_IN_HALF_WEEK)
tk += SECONDS_IN_WEEK;
mk = eph.m0 + eph.n*tk;
ek = mk;
ekold = ek + 1.0;
OneMinusecosE = 0; // Suppress the uninitialized warning.
while(fabs(ek-ekold)>1.0E-14)
{
ekold = ek;
OneMinusecosE = 1.0-eph.ecc*cos(ekold);
ek = ek + (mk-ekold+eph.ecc*sin(ekold))/OneMinusecosE;
}
sek = sin(ek);
cek = cos(ek);
ekdot = eph.n/OneMinusecosE;
relativistic = -4.442807633E-10*eph.ecc*eph.sqrta*sek;
pk = atan2(eph.sq1e2*sek,cek-eph.ecc) + eph.aop;
pkdot = eph.sq1e2*ekdot/OneMinusecosE;
s2pk = sin(2.0*pk);
c2pk = cos(2.0*pk);
uk = pk + eph.cus*s2pk + eph.cuc*c2pk;
suk = sin(uk);
cuk = cos(uk);
ukdot = pkdot*(1.0 + 2.0*(eph.cus*c2pk - eph.cuc*s2pk));
rk = eph.A*OneMinusecosE + eph.crc*c2pk + eph.crs*s2pk;
rkdot = eph.A*eph.ecc*sek*ekdot + 2.0*pkdot*(eph.crs*c2pk - eph.crc*s2pk);
ik = eph.inc0 + eph.idot*tk + eph.cic*c2pk + eph.cis*s2pk;
sik = sin(ik);
cik = cos(ik);
ikdot = eph.idot + 2.0*pkdot*(eph.cis*c2pk - eph.cic*s2pk);
xpk = rk*cuk;
ypk = rk*suk;
xpkdot = rkdot*cuk - ypk*ukdot;
ypkdot = rkdot*suk + xpk*ukdot;
ok = eph.omg0 + tk*eph.omgkdot - OMEGA_EARTH*eph.toe.sec;
sok = sin(ok);
cok = cos(ok);
pos[0] = xpk*cok - ypk*cik*sok;
pos[1] = xpk*sok + ypk*cik*cok;
pos[2] = ypk*sik;
tmp = ypkdot*cik - ypk*sik*ikdot;
vel[0] = -eph.omgkdot*pos[1] + xpkdot*cok - tmp*sok;
vel[1] = eph.omgkdot*pos[0] + xpkdot*sok + tmp*cok;
vel[2] = ypk*cik*ikdot + ypkdot*sik;
// Satellite clock correction
tk = g.sec - eph.toc.sec;
if(tk>SECONDS_IN_HALF_WEEK)
tk -= SECONDS_IN_WEEK;
else if(tk<-SECONDS_IN_HALF_WEEK)
tk += SECONDS_IN_WEEK;
clk[0] = eph.af0 + tk*(eph.af1 + tk*eph.af2) + relativistic - eph.tgd;
clk[1] = eph.af1 + 2.0*tk*eph.af2;
return;
}
/*! \brief Compute Subframe from Ephemeris
* \param[in] eph Ephemeris of given SV
* \param[out] sbf Array of five sub-frames, 10 long words each
*/
void eph2sbf(const ephem_t eph, const ionoutc_t ionoutc, unsigned long sbf[5][N_DWRD_SBF])
{
unsigned long wn;
unsigned long toe;
unsigned long toc;
unsigned long iode;
unsigned long iodc;
long deltan;
long cuc;
long cus;
long cic;
long cis;
long crc;
long crs;
unsigned long ecc;
unsigned long sqrta;
long m0;
long omg0;
long inc0;
long aop;
long omgdot;
long idot;
long af0;
long af1;
long af2;
long tgd;
int svhlth;
int codeL2;
unsigned long ura = 0UL;
unsigned long dataId = 1UL;
unsigned long sbf4_page25_svId = 63UL;
unsigned long sbf5_page25_svId = 51UL;
unsigned long wna;
unsigned long toa;
signed long alpha0,alpha1,alpha2,alpha3;
signed long beta0,beta1,beta2,beta3;
signed long A0,A1;
signed long dtls,dtlsf;
unsigned long tot,wnt,wnlsf,dn;
unsigned long sbf4_page18_svId = 56UL;
// FIXED: This has to be the "transmission" week number, not for the ephemeris reference time
//wn = (unsigned long)(eph.toe.week%1024);
wn = 0UL;
toe = (unsigned long)(eph.toe.sec/16.0);
toc = (unsigned long)(eph.toc.sec/16.0);
iode = (unsigned long)(eph.iode);
iodc = (unsigned long)(eph.iodc);
deltan = (long)(eph.deltan/POW2_M43/PI);
cuc = (long)(eph.cuc/POW2_M29);
cus = (long)(eph.cus/POW2_M29);
cic = (long)(eph.cic/POW2_M29);
cis = (long)(eph.cis/POW2_M29);
crc = (long)(eph.crc/POW2_M5);
crs = (long)(eph.crs/POW2_M5);
ecc = (unsigned long)(eph.ecc/POW2_M33);
sqrta = (unsigned long)(eph.sqrta/POW2_M19);
m0 = (long)(eph.m0/POW2_M31/PI);
omg0 = (long)(eph.omg0/POW2_M31/PI);
inc0 = (long)(eph.inc0/POW2_M31/PI);
aop = (long)(eph.aop/POW2_M31/PI);
omgdot = (long)(eph.omgdot/POW2_M43/PI);
idot = (long)(eph.idot/POW2_M43/PI);
af0 = (long)(eph.af0/POW2_M31);
af1 = (long)(eph.af1/POW2_M43);
af2 = (long)(eph.af2/POW2_M55);
tgd = (long)(eph.tgd/POW2_M31);
svhlth = (unsigned long)(eph.svhlth);
codeL2 = (unsigned long)(eph.codeL2);
wna = (unsigned long)(eph.toe.week%256);
toa = (unsigned long)(eph.toe.sec/4096.0);
alpha0 = (signed long)round(ionoutc.alpha0/POW2_M30);
alpha1 = (signed long)round(ionoutc.alpha1/POW2_M27);
alpha2 = (signed long)round(ionoutc.alpha2/POW2_M24);
alpha3 = (signed long)round(ionoutc.alpha3/POW2_M24);
beta0 = (signed long)round(ionoutc.beta0/2048.0);
beta1 = (signed long)round(ionoutc.beta1/16384.0);
beta2 = (signed long)round(ionoutc.beta2/65536.0);
beta3 = (signed long)round(ionoutc.beta3/65536.0);
A0 = (signed long)round(ionoutc.A0/POW2_M30);
A1 = (signed long)round(ionoutc.A1/POW2_M50);
dtls = (signed long)(ionoutc.dtls);
tot = (unsigned long)(ionoutc.tot/4096);
wnt = (unsigned long)(ionoutc.wnt%256);
// TO DO: Specify scheduled leap seconds in command options
// 2016/12/31 (Sat) -> WNlsf = 1929, DN = 7 (http://navigationservices.agi.com/GNSSWeb/)
// Days are counted from 1 to 7 (Sunday is 1).
wnlsf = 1929%256;
dn = 7;
dtlsf = 18;
// Subframe 1
sbf[0][0] = 0x8B0000UL<<6;
sbf[0][1] = 0x1UL<<8;
sbf[0][2] = ((wn&0x3FFUL)<<20) | ((codeL2&0x3UL)<<18) | ((ura&0xFUL)<<14) | ((svhlth&0x3FUL)<<8) | (((iodc>>8)&0x3UL)<<6);
sbf[0][3] = 0UL;
sbf[0][4] = 0UL;
sbf[0][5] = 0UL;
sbf[0][6] = (tgd&0xFFUL)<<6;
sbf[0][7] = ((iodc&0xFFUL)<<22) | ((toc&0xFFFFUL)<<6);
sbf[0][8] = ((af2&0xFFUL)<<22) | ((af1&0xFFFFUL)<<6);
sbf[0][9] = (af0&0x3FFFFFUL)<<8;
// Subframe 2
sbf[1][0] = 0x8B0000UL<<6;
sbf[1][1] = 0x2UL<<8;
sbf[1][2] = ((iode&0xFFUL)<<22) | ((crs&0xFFFFUL)<<6);
sbf[1][3] = ((deltan&0xFFFFUL)<<14) | (((m0>>24)&0xFFUL)<<6);
sbf[1][4] = (m0&0xFFFFFFUL)<<6;
sbf[1][5] = ((cuc&0xFFFFUL)<<14) | (((ecc>>24)&0xFFUL)<<6);
sbf[1][6] = (ecc&0xFFFFFFUL)<<6;
sbf[1][7] = ((cus&0xFFFFUL)<<14) | (((sqrta>>24)&0xFFUL)<<6);
sbf[1][8] = (sqrta&0xFFFFFFUL)<<6;
sbf[1][9] = (toe&0xFFFFUL)<<14;
// Subframe 3
sbf[2][0] = 0x8B0000UL<<6;
sbf[2][1] = 0x3UL<<8;
sbf[2][2] = ((cic&0xFFFFUL)<<14) | (((omg0>>24)&0xFFUL)<<6);
sbf[2][3] = (omg0&0xFFFFFFUL)<<6;
sbf[2][4] = ((cis&0xFFFFUL)<<14) | (((inc0>>24)&0xFFUL)<<6);
sbf[2][5] = (inc0&0xFFFFFFUL)<<6;
sbf[2][6] = ((crc&0xFFFFUL)<<14) | (((aop>>24)&0xFFUL)<<6);
sbf[2][7] = (aop&0xFFFFFFUL)<<6;
sbf[2][8] = (omgdot&0xFFFFFFUL)<<6;
sbf[2][9] = ((iode&0xFFUL)<<22) | ((idot&0x3FFFUL)<<8);
if (ionoutc.vflg==TRUE)
{
// Subframe 4, page 18
sbf[3][0] = 0x8B0000UL<<6;
sbf[3][1] = 0x4UL<<8;
sbf[3][2] = (dataId<<28) | (sbf4_page18_svId<<22) | ((alpha0&0xFFUL)<<14) | ((alpha1&0xFFUL)<<6);
sbf[3][3] = ((alpha2&0xFFUL)<<22) | ((alpha3&0xFFUL)<<14) | ((beta0&0xFFUL)<<6);
sbf[3][4] = ((beta1&0xFFUL)<<22) | ((beta2&0xFFUL)<<14) | ((beta3&0xFFUL)<<6);
sbf[3][5] = (A1&0xFFFFFFUL)<<6;
sbf[3][6] = ((A0>>8)&0xFFFFFFUL)<<6;
sbf[3][7] = ((A0&0xFFUL)<<22) | ((tot&0xFFUL)<<14) | ((wnt&0xFFUL)<<6);
sbf[3][8] = ((dtls&0xFFUL)<<22) | ((wnlsf&0xFFUL)<<14) | ((dn&0xFFUL)<<6);
sbf[3][9] = (dtlsf&0xFFUL)<<22;
}
else
{
// Subframe 4, page 25
sbf[3][0] = 0x8B0000UL<<6;
sbf[3][1] = 0x4UL<<8;
sbf[3][2] = (dataId<<28) | (sbf4_page25_svId<<22);
sbf[3][3] = 0UL;
sbf[3][4] = 0UL;
sbf[3][5] = 0UL;
sbf[3][6] = 0UL;
sbf[3][7] = 0UL;
sbf[3][8] = 0UL;
sbf[3][9] = 0UL;
}
// Subframe 5, page 25
sbf[4][0] = 0x8B0000UL<<6;
sbf[4][1] = 0x5UL<<8;
sbf[4][2] = (dataId<<28) | (sbf5_page25_svId<<22) | ((toa&0xFFUL)<<14) | ((wna&0xFFUL)<<6);
sbf[4][3] = 0UL;
sbf[4][4] = 0UL;
sbf[4][5] = 0UL;
sbf[4][6] = 0UL;
sbf[4][7] = 0UL;
sbf[4][8] = 0UL;
sbf[4][9] = 0UL;
return;
}
/*! \brief Count number of bits set to 1
* \param[in] v long word in whihc bits are counted
* \returns Count of bits set to 1
*/
unsigned long countBits(unsigned long v)
{
unsigned long c;
const int S[] = {1, 2, 4, 8, 16};
const unsigned long B[] = {
0x55555555, 0x33333333, 0x0F0F0F0F, 0x00FF00FF, 0x0000FFFF};
c = v;
c = ((c >> S[0]) & B[0]) + (c & B[0]);
c = ((c >> S[1]) & B[1]) + (c & B[1]);
c = ((c >> S[2]) & B[2]) + (c & B[2]);
c = ((c >> S[3]) & B[3]) + (c & B[3]);
c = ((c >> S[4]) & B[4]) + (c & B[4]);
return(c);
}
/*! \brief Compute the Checksum for one given word of a subframe
* \param[in] source The input data
* \param[in] nib Does this word contain non-information-bearing bits?
* \returns Computed Checksum
*/
unsigned long computeChecksum(unsigned long source, int nib)
{
/*
Bits 31 to 30 = 2 LSBs of the previous transmitted word, D29* and D30*
Bits 29 to 6 = Source data bits, d1, d2, ..., d24
Bits 5 to 0 = Empty parity bits
*/
/*
Bits 31 to 30 = 2 LSBs of the previous transmitted word, D29* and D30*
Bits 29 to 6 = Data bits transmitted by the SV, D1, D2, ..., D24
Bits 5 to 0 = Computed parity bits, D25, D26, ..., D30
*/
/*
1 2 3
bit 12 3456 7890 1234 5678 9012 3456 7890
--- -------------------------------------
D25 11 1011 0001 1111 0011 0100 1000 0000
D26 01 1101 1000 1111 1001 1010 0100 0000
D27 10 1110 1100 0111 1100 1101 0000 0000
D28 01 0111 0110 0011 1110 0110 1000 0000
D29 10 1011 1011 0001 1111 0011 0100 0000
D30 00 1011 0111 1010 1000 1001 1100 0000
*/
unsigned long bmask[6] = {
0x3B1F3480UL, 0x1D8F9A40UL, 0x2EC7CD00UL,
0x1763E680UL, 0x2BB1F340UL, 0x0B7A89C0UL };
unsigned long D;
unsigned long d = source & 0x3FFFFFC0UL;
unsigned long D29 = (source>>31)&0x1UL;
unsigned long D30 = (source>>30)&0x1UL;
if (nib) // Non-information bearing bits for word 2 and 10
{
/*
Solve bits 23 and 24 to presearve parity check
with zeros in bits 29 and 30.
*/
if ((D30 + countBits(bmask[4] & d)) % 2)
d ^= (0x1UL<<6);
if ((D29 + countBits(bmask[5] & d)) % 2)
d ^= (0x1UL<<7);
}
D = d;
if (D30)
D ^= 0x3FFFFFC0UL;
D |= ((D29 + countBits(bmask[0] & d)) % 2) << 5;
D |= ((D30 + countBits(bmask[1] & d)) % 2) << 4;
D |= ((D29 + countBits(bmask[2] & d)) % 2) << 3;
D |= ((D30 + countBits(bmask[3] & d)) % 2) << 2;
D |= ((D30 + countBits(bmask[4] & d)) % 2) << 1;
D |= ((D29 + countBits(bmask[5] & d)) % 2);
D &= 0x3FFFFFFFUL;
//D |= (source & 0xC0000000UL); // Add D29* and D30* from source data bits
return(D);
}
/*! \brief Replace all 'E' exponential designators to 'D'
* \param str String in which all occurrences of 'E' are replaced with * 'D'
* \param len Length of input string in bytes
* \returns Number of characters replaced
*/
int replaceExpDesignator(char *str, int len)
{
int i,n=0;
for (i=0; i<len; i++)
{
if (str[i]=='D')
{
n++;
str[i] = 'E';
}
}
return(n);
}
double subGpsTime(gpstime_t g1, gpstime_t g0)
{
double dt;
dt = g1.sec - g0.sec;
dt += (double)(g1.week - g0.week) * SECONDS_IN_WEEK;
return(dt);
}
gpstime_t incGpsTime(gpstime_t g0, double dt)
{
gpstime_t g1;
g1.week = g0.week;
g1.sec = g0.sec + dt;
g1.sec = round(g1.sec*1000.0)/1000.0; // Avoid rounding error
while (g1.sec>=SECONDS_IN_WEEK)
{
g1.sec -= SECONDS_IN_WEEK;
g1.week++;
}
while (g1.sec<0.0)
{
g1.sec += SECONDS_IN_WEEK;
g1.week--;
}
return(g1);
}
/*! \brief Read Ephemersi data from the RINEX Navigation file */
/* \param[out] eph Array of Output SV ephemeris data
* \param[in] fname File name of the RINEX file
* \returns Number of sets of ephemerides in the file
*/
int readRinexNavAll(ephem_t eph[][MAX_SAT], ionoutc_t *ionoutc, const char *fname)
{
FILE *fp;
int ieph;
int sv;
char str[MAX_CHAR];
char tmp[20];
datetime_t t;
gpstime_t g;
gpstime_t g0;
double dt;
int flags = 0x0;
if (NULL==(fp=fopen(fname, "rt")))
return(-1);
// Clear valid flag
for (ieph=0; ieph<EPHEM_ARRAY_SIZE; ieph++)
for (sv=0; sv<MAX_SAT; sv++)
eph[ieph][sv].vflg = 0;
// Read header lines
while (1)
{
if (NULL==fgets(str, MAX_CHAR, fp))
break;
if (strncmp(str+60, "END OF HEADER", 13)==0)
break;
else if (strncmp(str+60, "ION ALPHA", 9)==0)
{
strncpy(tmp, str+2, 12);
tmp[12] = 0;
replaceExpDesignator(tmp, 12);
ionoutc->alpha0 = atof(tmp);
strncpy(tmp, str+14, 12);
tmp[12] = 0;
replaceExpDesignator(tmp, 12);
ionoutc->alpha1 = atof(tmp);
strncpy(tmp, str+26, 12);
tmp[12] = 0;
replaceExpDesignator(tmp, 12);
ionoutc->alpha2 = atof(tmp);
strncpy(tmp, str+38, 12);
tmp[12] = 0;
replaceExpDesignator(tmp, 12);
ionoutc->alpha3 = atof(tmp);
flags |= 0x1;
}
else if (strncmp(str+60, "ION BETA", 8)==0)
{
strncpy(tmp, str+2, 12);
tmp[12] = 0;
replaceExpDesignator(tmp, 12);
ionoutc->beta0 = atof(tmp);
strncpy(tmp, str+14, 12);
tmp[12] = 0;
replaceExpDesignator(tmp, 12);
ionoutc->beta1 = atof(tmp);
strncpy(tmp, str+26, 12);
tmp[12] = 0;
replaceExpDesignator(tmp, 12);
ionoutc->beta2 = atof(tmp);
strncpy(tmp, str+38, 12);
tmp[12] = 0;
replaceExpDesignator(tmp, 12);
ionoutc->beta3 = atof(tmp);
flags |= 0x1<<1;
}
else if (strncmp(str+60, "DELTA-UTC", 9)==0)
{
strncpy(tmp, str+3, 19);
tmp[19] = 0;
replaceExpDesignator(tmp, 19);
ionoutc->A0 = atof(tmp);
strncpy(tmp, str+22, 19);
tmp[19] = 0;
replaceExpDesignator(tmp, 19);
ionoutc->A1 = atof(tmp);
strncpy(tmp, str+41, 9);
tmp[9] = 0;
ionoutc->tot = atoi(tmp);
strncpy(tmp, str+50, 9);
tmp[9] = 0;
ionoutc->wnt = atoi(tmp);
if (ionoutc->tot%4096==0)
flags |= 0x1<<2;
}
else if (strncmp(str+60, "LEAP SECONDS", 12)==0)
{
strncpy(tmp, str, 6);
tmp[6] = 0;
ionoutc->dtls = atoi(tmp);
flags |= 0x1<<3;
}
}
ionoutc->vflg = FALSE;
if (flags==0xF) // Read all Iono/UTC lines
ionoutc->vflg = TRUE;
// Read ephemeris blocks
g0.week = -1;
ieph = 0;
while (1)
{
if (NULL==fgets(str, MAX_CHAR, fp))
break;
// PRN
strncpy(tmp, str, 2);
tmp[2] = 0;
sv = atoi(tmp)-1;
// EPOCH
strncpy(tmp, str+3, 2);
tmp[2] = 0;
t.y = atoi(tmp) + 2000;
strncpy(tmp, str+6, 2);
tmp[2] = 0;
t.m = atoi(tmp);
strncpy(tmp, str+9, 2);
tmp[2] = 0;
t.d = atoi(tmp);
strncpy(tmp, str+12, 2);
tmp[2] = 0;
t.hh = atoi(tmp);
strncpy(tmp, str+15, 2);
tmp[2] = 0;
t.mm = atoi(tmp);
strncpy(tmp, str+18, 4);
tmp[2] = 0;
t.sec = atof(tmp);
date2gps(&t, &g);
if (g0.week==-1)
g0 = g;
// Check current time of clock
dt = subGpsTime(g, g0);
if (dt>SECONDS_IN_HOUR)
{
g0 = g;
ieph++; // a new set of ephemerides
if (ieph>=EPHEM_ARRAY_SIZE)
break;
}
// Date and time
eph[ieph][sv].t = t;
// SV CLK
eph[ieph][sv].toc = g;
strncpy(tmp, str+22, 19);
tmp[19] = 0;
replaceExpDesignator(tmp, 19); // tmp[15]='E';
eph[ieph][sv].af0 = atof(tmp);