File: ccd_simulator.cpp

package info (click to toggle)
libindi 0.9.8.1-5.1
  • links: PTS, VCS
  • area: main
  • in suites: jessie, jessie-kfreebsd
  • size: 4,600 kB
  • ctags: 7,283
  • sloc: cpp: 34,410; ansic: 20,227; xml: 294; makefile: 13
file content (1147 lines) | stat: -rw-r--r-- 35,115 bytes parent folder | download
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
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
/*******************************************************************************
  Copyright(c) 2010 Gerry Rozema. All rights reserved.

 This library is free software; you can redistribute it and/or
 modify it under the terms of the GNU Library General Public
 License version 2 as published by the Free Software Foundation.
 .
 This library is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 Library General Public License for more details.
 .
 You should have received a copy of the GNU Library General Public License
 along with this library; see the file COPYING.LIB.  If not, write to
 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 Boston, MA 02110-1301, USA.
*******************************************************************************/
#include "ccd_simulator.h"

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <math.h>
#include <string.h>

#include <memory>

#include <libnova.h>

// We declare an auto pointer to ccdsim.
std::auto_ptr<CCDSim> ccdsim(0);

void ISPoll(void *p);


void ISInit()
{
   static int isInit =0;

   if (isInit == 1)
       return;

    isInit = 1;
    if(ccdsim.get() == 0) ccdsim.reset(new CCDSim());
    //IEAddTimer(POLLMS, ISPoll, NULL);

}

void ISGetProperties(const char *dev)
{
        ISInit();
        ccdsim->ISGetProperties(dev);
}

void ISNewSwitch(const char *dev, const char *name, ISState *states, char *names[], int num)
{
        ISInit();
        ccdsim->ISNewSwitch(dev, name, states, names, num);
}

void ISNewText(	const char *dev, const char *name, char *texts[], char *names[], int num)
{
        ISInit();
        ccdsim->ISNewText(dev, name, texts, names, num);
}

void ISNewNumber(const char *dev, const char *name, double values[], char *names[], int num)
{
        ISInit();
        ccdsim->ISNewNumber(dev, name, values, names, num);
}

void ISNewBLOB (const char *dev, const char *name, int sizes[], int blobsizes[], char *blobs[], char *formats[], char *names[], int n)
{
  INDI_UNUSED(dev);
  INDI_UNUSED(name);
  INDI_UNUSED(sizes);
  INDI_UNUSED(blobsizes);
  INDI_UNUSED(blobs);
  INDI_UNUSED(formats);
  INDI_UNUSED(names);
  INDI_UNUSED(n);
}
void ISSnoopDevice (XMLEle *root)
{
    ISInit();
    ccdsim->ISSnoopDevice(root);
}


CCDSim::CCDSim()
{
    //ctor
    testvalue=0;
    AbortGuideFrame=false;
    AbortPrimaryFrame = false;
    ShowStarField=true;

    Capability cap;

    cap.canAbort = true;
    cap.canBin = true;
    cap.canSubFrame = true;
    cap.hasCooler = false;
    cap.hasGuideHead = true;
    cap.hasShutter = true;
    cap.hasST4Port = true;

    SetCapability(&cap);

    polarError=0;
    polarDrift=0;

    usePE = false;
    raPE=RA;
    decPE=Dec;

    //  sxvh9
    bias=1500;
    maxnoise=20;
    maxval=65000;
    maxpix=0;
    minpix =65000;
    limitingmag=11.5;
    saturationmag=2;
    focallength=1280;   //  focal length of the telescope in millimeters
    guider_focallength=1280;
    OAGoffset=0;    //  An oag is offset this much from center of scope position (arcminutes);
    skyglow=40;

    seeing=3.5;         //  fwhm of our stars
    ImageScalex=1.0;    //  preset with a valid non-zero
    ImageScaley=1.0;
    time(&RunStart);

    //  Our PEPeriod is 8 minutes
    //  and we have a 22 arcsecond swing
    PEPeriod=8*60;
    PEMax=11;
    GuideRate=7;    //  guide rate is 7 arcseconds per second
    TimeFactor=1;

    SimulatorSettingsNV = new INumberVectorProperty;
    TimeFactorSV = new ISwitchVectorProperty;

    // Filter stuff
    FilterSlotN[0].min = 1;
    FilterSlotN[0].max = 5;

}

bool CCDSim::SetupParms()
{
    int nbuf;
    SetCCDParams(SimulatorSettingsN[0].value,SimulatorSettingsN[1].value,16,SimulatorSettingsN[2].value,SimulatorSettingsN[3].value);

    //  Kwiq
    maxnoise=SimulatorSettingsN[8].value;
    skyglow=SimulatorSettingsN[9].value;
    maxval=SimulatorSettingsN[4].value;
    bias=SimulatorSettingsN[5].value;
    limitingmag=SimulatorSettingsN[7].value;
    saturationmag=SimulatorSettingsN[6].value;
    OAGoffset=SimulatorSettingsN[10].value;    //  An oag is offset this much from center of scope position (arcminutes);
    polarError=SimulatorSettingsN[11].value;
    polarDrift=SimulatorSettingsN[12].value;

    nbuf = PrimaryCCD.getXRes() * PrimaryCCD.getYRes() * PrimaryCCD.getBPP()/8;
    nbuf += 512;
    PrimaryCCD.setFrameBufferSize(nbuf);

    GetFilterNames(FILTER_TAB);

    return true;
}

bool CCDSim::Connect()
{

    int nbuf;

    SetTimer(1000);     //  start the timer
    return true;
}

CCDSim::~CCDSim()
{
    //dtor
}

const char * CCDSim::getDefaultName()
{
        return (char *)"CCD Simulator";
}

bool CCDSim::initProperties()
{
    //  Most hardware layers wont actually have indi properties defined
    //  but the simulators are a special case
    INDI::CCD::initProperties();

    IUFillNumber(&SimulatorSettingsN[0],"SIM_XRES","CCD X resolution","%4.0f",0,2048,0,1280);
    IUFillNumber(&SimulatorSettingsN[1],"SIM_YRES","CCD Y resolution","%4.0f",0,2048,0,1024);
    IUFillNumber(&SimulatorSettingsN[2],"SIM_XSIZE","CCD X Pixel Size","%4.2f",0,60,0,5.2);
    IUFillNumber(&SimulatorSettingsN[3],"SIM_YSIZE","CCD Y Pixel Size","%4.2f",0,60,0,5.2);
    IUFillNumber(&SimulatorSettingsN[4],"SIM_MAXVAL","CCD Maximum ADU","%4.0f",0,65000,0,65000);
    IUFillNumber(&SimulatorSettingsN[5],"SIM_BIAS","CCD Bias","%4.0f",0,6000,0,10);
    IUFillNumber(&SimulatorSettingsN[6],"SIM_SATURATION","Saturation Mag","%4.1f",0,20,0,1.0);
    IUFillNumber(&SimulatorSettingsN[7],"SIM_LIMITINGMAG","Limiting Mag","%4.1f",0,20,0,17.0);
    IUFillNumber(&SimulatorSettingsN[8],"SIM_NOISE","CCD Noise","%4.0f",0,6000,0,10);
    IUFillNumber(&SimulatorSettingsN[9],"SIM_SKYGLOW","Sky Glow (magnitudes)","%4.1f",0,6000,0,19.5);
    IUFillNumber(&SimulatorSettingsN[10],"SIM_OAGOFFSET","Oag Offset (arcminutes)","%4.1f",0,6000,0,0);
    IUFillNumber(&SimulatorSettingsN[11],"SIM_POLAR","PAE (arcminutes)","%4.1f",-600,600,0,0); /* PAE = Polar Alignment Error */
    IUFillNumber(&SimulatorSettingsN[12],"SIM_POLARDRIFT","PAE Drift (minutes)","%4.1f",0,6000,0,0);
    IUFillNumberVector(SimulatorSettingsNV,SimulatorSettingsN,13,getDeviceName(),"SIMULATOR_SETTINGS","Simulator Settings","Simulator Config",IP_RW,60,IPS_IDLE);

    IUFillSwitch(&TimeFactorS[0],"1X","Actual Time",ISS_ON);
    IUFillSwitch(&TimeFactorS[1],"10X","10x",ISS_OFF);
    IUFillSwitch(&TimeFactorS[2],"100X","100x",ISS_OFF);
    IUFillSwitchVector(TimeFactorSV,TimeFactorS,3,getDeviceName(),"ON_TIME_FACTOR","Time Factor","Simulator Config",IP_RW,ISR_1OFMANY,60,IPS_IDLE);

    IUFillNumber(&FWHMN[0],"SIM_FWHM","FWHM (arcseconds)","%4.2f",0,60,0,7.5);
    IUFillNumberVector(&FWHMNP,FWHMN,1,ActiveDeviceT[1].text, "FWHM","FWHM",OPTIONS_TAB,IP_RO,60,IPS_IDLE);

    IUFillNumber(&ScopeParametersN[0],"TELESCOPE_APERTURE","Aperture (mm)","%g",50,4000,0,0.0);
    IUFillNumber(&ScopeParametersN[1],"TELESCOPE_FOCAL_LENGTH","Focal Length (mm)","%g",100,10000,0,0.0 );
    IUFillNumber(&ScopeParametersN[2],"GUIDER_APERTURE","Guider Aperture (mm)","%g",50,4000,0,0.0);
    IUFillNumber(&ScopeParametersN[3],"GUIDER_FOCAL_LENGTH","Guider Focal Length (mm)","%g",100,10000,0,0.0 );
    IUFillNumberVector(&ScopeParametersNP,ScopeParametersN,4,ActiveDeviceT[0].text,"TELESCOPE_INFO","Scope Properties",OPTIONS_TAB,IP_RW,60,IPS_OK);

    IUFillNumber(&EqPEN[0],"RA_PE","RA (hh:mm:ss)","%010.6m",0,24,0,0);
    IUFillNumber(&EqPEN[1],"DEC_PE","DEC (dd:mm:ss)","%010.6m",-90,90,0,0);
    IUFillNumberVector(&EqPENP,EqPEN,2,ActiveDeviceT[0].text,"EQUATORIAL_PE","EQ PE","Main Control",IP_RW,60,IPS_IDLE);

    IDSnoopDevice(ActiveDeviceT[0].text,"EQUATORIAL_PE");
    IDSnoopDevice(ActiveDeviceT[0].text,"TELESCOPE_INFO");
    IDSnoopDevice(ActiveDeviceT[1].text,"FWHM");

    initFilterProperties(getDeviceName(), FILTER_TAB);

    FilterSlotN[0].min = 1;
    FilterSlotN[0].max = 5;

    addDebugControl();

    return true;
}

void CCDSim::ISGetProperties (const char *dev)
{
    //  First we let our parent populate

    //IDLog("CCDSim IsGetProperties with %s\n",dev);
    INDI::CCD::ISGetProperties(dev);

    defineNumber(SimulatorSettingsNV);
    defineSwitch(TimeFactorSV);

    return;
}

bool CCDSim::updateProperties()
{
    INDI::CCD::updateProperties();

    if (isConnected())
    {
        SetupParms();

        if(HasGuideHead())
        {
            SetGuiderParams(500,290,16,9.8,12.6);
            GuideCCD.setFrameBufferSize(GuideCCD.getXRes() * GuideCCD.getYRes() * 2);
        }

        // Define the Filter Slot and name properties
        defineNumber(&FilterSlotNP);
        if (FilterNameT != NULL)
            defineText(FilterNameTP);
    } else
    {
        deleteProperty(FilterSlotNP.name);
        deleteProperty(FilterNameTP->name);
    }

    return true;
}


bool CCDSim::Disconnect()
{
    return true;
}

bool CCDSim::StartExposure(float duration)
{
    //  for the simulator, we can just draw the frame now
    //  and it will get returned at the right time
    //  by the timer routines
    AbortPrimaryFrame=false;
    ExposureRequest=duration;

    PrimaryCCD.setExposureDuration(duration);
    gettimeofday(&ExpStart,NULL);
    //  Leave the proper time showing for the draw routines
    DrawCcdFrame(&PrimaryCCD);
    //  Now compress the actual wait time
    ExposureRequest=duration*TimeFactor;
    InExposure=true;
    return true;
}

bool CCDSim::StartGuideExposure(float n)
{
    GuideExposureRequest=n;
    AbortGuideFrame = false;
    GuideCCD.setExposureDuration(n);
    DrawCcdFrame(&GuideCCD);
    gettimeofday(&GuideExpStart,NULL);
    InGuideExposure=true;
    return true;
}

bool CCDSim::AbortExposure()
{
    if (!InExposure)
        return true;

    AbortPrimaryFrame = true;

    return true;
}

bool CCDSim::AbortGuideExposure()
{
    //IDLog("Enter AbortGuideExposure\n");
    if(!InGuideExposure) return true;   //  no need to abort if we aren't doing one
    AbortGuideFrame=true;
    return true;
}

float CCDSim::CalcTimeLeft(timeval start,float req)
{
    double timesince;
    double timeleft;
    struct timeval now;
    gettimeofday(&now,NULL);

    timesince=(double)(now.tv_sec * 1000.0 + now.tv_usec/1000) - (double)(start.tv_sec * 1000.0 + start.tv_usec/1000);
    timesince=timesince/1000;
    timeleft=req-timesince;
    return timeleft;
}

void CCDSim::TimerHit()
{
    int nexttimer=1000;

    if(isConnected() == false) return;  //  No need to reset timer if we are not connected anymore

    if(InExposure)
    {
        if (AbortPrimaryFrame)
        {
            InExposure = false;
            AbortPrimaryFrame = false;
        }
        else
        {
            float timeleft;
            timeleft=CalcTimeLeft(ExpStart,ExposureRequest);

            //IDLog("CCD Exposure left: %g - Requset: %g\n", timeleft, ExposureRequest);
            if (timeleft < 0)
                 timeleft = 0;

            PrimaryCCD.setExposureLeft(timeleft);

            if(timeleft < 1.0)
            {
                if(timeleft <= 0.001)
                {
                    InExposure=false;
                    ExposureComplete(&PrimaryCCD);
                } else
                {
                    nexttimer=timeleft*1000;    //  set a shorter timer
                }
            }
        }
    }

    if(InGuideExposure)
    {
        float timeleft;
        timeleft=CalcTimeLeft(GuideExpStart,GuideExposureRequest);


        //IDLog("GUIDE Exposure left: %g - Requset: %g\n", timeleft, GuideExposureRequest);

        if (timeleft < 0)
             timeleft = 0;

        //ImageExposureN[0].value = timeleft;
        //IDSetNumber(ImageExposureNP, NULL);
        GuideCCD.setExposureLeft(timeleft);

        if(timeleft < 1.0)
        {
            if(timeleft <= 0.001)
            {
                InGuideExposure=false;
                if(!AbortGuideFrame)
                {
                    //IDLog("Sending guider frame\n");
                    ExposureComplete(&GuideCCD);
                    if(InGuideExposure)
                    {    //  the call to complete triggered another exposure
                        timeleft=CalcTimeLeft(GuideExpStart,GuideExposureRequest);
                        if(timeleft <1.0)
                        {
                            nexttimer=timeleft*1000;
                        }
                    }
                } else
                {
                    IDLog("Not sending guide frame cuz of abort\n");
                }
                AbortGuideFrame=false;
            } else
            {
                nexttimer=timeleft*1000;    //  set a shorter timer
            }
        }
    }
    SetTimer(nexttimer);
    return;
}

int CCDSim::DrawCcdFrame(CCDChip *targetChip)
{
    //  Ok, lets just put a silly pattern into this
    //  CCd frame is 16 bit data
    unsigned short int *ptr;
    unsigned short int val;
    float ExposureTime;
    float targetFocalLength;

    ptr=(unsigned short int *) targetChip->getFrameBuffer();

    if (targetChip->getXRes() == 500)
    {
        targetFocalLength = guider_focallength;
        ExposureTime = GuideExposureRequest;
    }
    else
    {
        targetFocalLength = focallength;
        ExposureTime = ExposureRequest;
    }

    if(ShowStarField)
    {
        char gsccmd[250];
        FILE *pp;
        int stars=0;
        int lines=0;
        int drawn=0;
        int x,y;
        float PEOffset;
        float PESpot;
        float decDrift;
        double rad;  //  telescope ra in degrees
        double rar;  //  telescope ra in radians
        double decr; //  telescope dec in radians;
        int nwidth=0, nheight=0;

        double timesince;
        time_t now;
        time(&now);

        //  Lets figure out where we are on the pe curve
        timesince=difftime(now,RunStart);
        //  This is our spot in the curve
        PESpot=timesince/PEPeriod;
        //  Now convert to radians
        PESpot=PESpot*2.0*3.14159;

        PEOffset=PEMax*sin(PESpot);
        //fprintf(stderr,"PEOffset = %4.2f arcseconds timesince %4.2f\n",PEOffset,timesince);
        PEOffset=PEOffset/3600;     //  convert to degrees
        //PeOffset=PeOffset/15;       //  ra is in h:mm

        //  Start by clearing the frame buffer
        memset(targetChip->getFrameBuffer(),0,targetChip->getFrameBufferSize());


        //  Spin up a set of plate constants that will relate
        //  ra/dec of stars, to our fictitious ccd layout

        //  to account for various rotations etc
        //  we should spin up some plate constants here
        //  then we can use these constants to rotate and offset
        //  the standard co-ordinates on each star for drawing
        //  a ccd frame;
        double pa,pb,pc,pd,pe,pf;
        //  Since this is a simple ccd, correctly aligned
        //  for now we cheat
        //  no offset or rotation for and y axis means
        pb=0.0;
        nwidth = targetChip->getXRes() / targetChip->getBinX();
        pc=nwidth/2;
        pd=0.0;

        nheight = targetChip->getYRes() / targetChip->getBinY();
        pf=nheight/2;
        //  and we do a simple scale for x and y locations
        //  based on the focal length and pixel size
        //  focal length in mm, pixels in microns
        pa=targetFocalLength/targetChip->getPixelSizeX()*1000/targetChip->getBinX();
        pe=targetFocalLength/targetChip->getPixelSizeY()*1000/targetChip->getBinY();

        //IDLog("Pixels are %4.2f %4.2f  pa %6.4f  pe %6.4f\n",PixelSizex,PixelSizey,pa,pe);

        //  these numbers are now pixels per radian
        float Scalex;
        float Scaley;
        Scalex=pa*0.0174532925;    //  pixels per degree
        Scalex=Scalex/3600.0;           // pixels per arcsecond
        Scalex=1.0/Scalex;  //  arcseconds per pixel

        Scaley=pe*0.0174532925;    //  pixels per degree
        Scaley=Scaley/3600.0;           // pixels per arcsecond
        Scaley=1.0/Scaley;  //  arcseconds per pixel
        //qq=qq/3600; //  arcseconds per pixel

        //IDLog("Pixel scale is %4.2f x %4.2f\n",Scalex,Scaley);
        ImageScalex=Scalex;
        ImageScaley=Scaley;

        if (usePE == false)
        {
            raPE  = RA;
            decPE = Dec;

            ln_equ_posn epochPos, J2000Pos;
            epochPos.ra   = raPE*15.0;
            epochPos.dec  = decPE;

            // Convert from JNow to J2000
            ln_get_equ_prec2(&epochPos, ln_get_julian_from_sys(), JD2000, &J2000Pos);

            raPE  = J2000Pos.ra/15.0;
            decPE = J2000Pos.dec;
        }

        //  calc this now, we will use it a lot later
        rad=raPE*15.0;
        rar=rad*0.0174532925;
        //  offsetting the dec by the guide head offset
        float cameradec;
        cameradec=decPE+OAGoffset/60;
        decr=cameradec*0.0174532925;

        decDrift = (polarDrift * polarError * cos(decr)) / 3.81;

        // Add declination drift, if any.
        decr += decDrift/3600.0 * 0.0174532925;

        //fprintf(stderr,"decPE %7.5f  cameradec %7.5f  CenterOffsetDec %4.4f\n",decPE,cameradec,CenterOffsetDec);
        //  now lets calculate the radius we need to fetch
        float radius;

        radius=sqrt((Scalex*Scalex*targetChip->getXRes()/2.0*targetChip->getXRes()/2.0)+(Scaley*Scaley*targetChip->getYRes()/2.0*targetChip->getYRes()/2.0));
        //  we have radius in arcseconds now
        radius=radius/60;   //  convert to arcminutes
        //fprintf(stderr,"Lookup radius %4.2f\n",radius);
        //radius=radius*2;

        //  A saturationmag star saturates in one second
        //  and a limitingmag produces a one adu level in one second
        //  solve for zero point and system gain

        k=(saturationmag-limitingmag)/((-2.5*log(maxval))-(-2.5*log(1.0/2.0)));
        z=saturationmag-k*(-2.5*log(maxval));
        //z=z+saturationmag;

        //IDLog("K=%4.2f  Z=%4.2f\n",k,z);

        //  Should probably do some math here to figure out the dimmest
        //  star we can see on this exposure
        //  and only fetch to that magnitude
        //  for now, just use the limiting mag number with some room to spare
        float lookuplimit;

        lookuplimit=limitingmag;
        lookuplimit=lookuplimit;
        if(radius > 60) lookuplimit=11;

        //  if this is a light frame, we need a star field drawn
        CCDChip::CCD_FRAME ftype = targetChip->getFrameType();

        if (ftype==CCDChip::LIGHT_FRAME)
        {
            //sprintf(gsccmd,"gsc -c %8.6f %+8.6f -r 120 -m 0 9.1",rad+PEOffset,decPE);
            sprintf(gsccmd,"gsc -c %8.6f %+8.6f -r %4.1f -m 0 %4.2f -n 3000",rad+PEOffset,cameradec,radius,lookuplimit);
            //fprintf(stderr,"gsccmd %s\n",gsccmd);
            pp=popen(gsccmd,"r");
            if(pp != NULL) {
                char line[256];
                while(fgets(line,256,pp)!=NULL)
                {
                    //fprintf(stderr,"%s",line);

                    //  ok, lets parse this line for specifcs we want
                    char id[20];
                    char plate[6];
                    char ob[6];
                    float mag;
                    float mage;
                    float ra;
                    float dec;
                    float pose;
                    int band;
                    float dist;
                    int dir;
                    int c;
                    int rc;

                    rc=sscanf(line,"%10s %f %f %f %f %f %d %d %4s %2s %f %d",
                            id,&ra,&dec,&pose,&mag,&mage,&band,&c,plate,ob,&dist,&dir);
                    //fprintf(stderr,"Parsed %d items\n",rc);
                    if(rc==12) {
                        lines++;
                        //if(c==0) {
                        stars++;
                        //fprintf(stderr,"%s %8.4f %8.4f %5.2f %5.2f %d\n",id,ra,dec,mag,dist,dir);

                        //  Convert the ra/dec to standard co-ordinates
                        double sx;   //  standard co-ords
                        double sy;   //
                        double srar;        //  star ra in radians
                        double sdecr;       //  star dec in radians;
                        double ccdx;
                        double ccdy;

                        //fprintf(stderr,"line %s",line);
                        //fprintf(stderr,"parsed %6.5f %6.5f\n",ra,dec);

                        srar=ra*0.0174532925;
                        sdecr=dec*0.0174532925;
                        //  Handbook of astronomical image processing
                        //  page 253
                        //  equations 9.1 and 9.2
                        //  convert ra/dec to standard co-ordinates

                        sx=cos(decr)*sin(srar-rar)/( cos(decr)*cos(sdecr)*cos(srar-rar)+sin(decr)*sin(sdecr) );
                        sy=(sin(decr)*cos(sdecr)*cos(srar-rar)-cos(decr)*sin(sdecr))/( cos(decr)*cos(sdecr)*cos(srar-rar)+sin(decr)*sin(sdecr) );

                        //  now convert to microns
                        ccdx=pa*sx+pb*sy+pc;
                        ccdy=pd*sx+pe*sy+pf;


                        rc=DrawImageStar(targetChip, mag,ccdx,ccdy);
                        drawn+=rc;
                        if(rc==1)
                        {
                            //fprintf(stderr,"star %s scope %6.4f %6.4f star %6.4f %6.4f  ccd %6.2f %6.2f\n",id,rad,decPE,ra,dec,ccdx,ccdy);
                            //fprintf(stderr,"star %s ccd %6.2f %6.2f\n",id,ccdx,ccdy);
                        }
                    }
                }
                pclose(pp);
            } else
            {
                IDMessage(getDeviceName(),"Error looking up stars, is gsc installed with appropriate environment variables set ??");
                //fprintf(stderr,"Error doing gsc lookup\n");
            }
            if(drawn==0)
            {
                IDMessage(getDeviceName(),"Got no stars, is gsc installed with appropriate environment variables set ??");

            }
        }
        //fprintf(stderr,"Got %d stars from %d lines drew %d\n",stars,lines,drawn);

        //  now we need to add background sky glow, with vignetting
        //  this is essentially the same math as drawing a dim star with
        //  fwhm equivalent to the full field of view


        if (ftype==CCDChip::LIGHT_FRAME || ftype==CCDChip::FLAT_FRAME)
        {
            float skyflux;
            float glow;
            //  calculate flux from our zero point and gain values
            glow=skyglow;
            if(ftype==CCDChip::FLAT_FRAME)
            {
                //  Assume flats are done with a diffuser
                //  in broad daylight, so, the sky magnitude
                //  is much brighter than at night
                glow=skyglow/10;
            }

            //fprintf(stderr,"Using glow %4.2f\n",glow);

            skyflux=pow(10,((glow-z)*k/-2.5));
            //  ok, flux represents one second now
            //  scale up linearly for exposure time
            skyflux=skyflux*ExposureTime*targetChip->getBinX()*targetChip->getBinY();
           //IDLog("SkyFlux = %g ExposureRequest %g\n",skyflux,ExposureTime);

            unsigned short *pt;

            pt=(unsigned short int *)targetChip->getFrameBuffer();

            nheight = targetChip->getSubH() / targetChip->getBinY();
            nwidth  = targetChip->getSubW() / targetChip->getBinX();

            for(int y=0; y< nheight; y++)
            {
                for(int x=0; x< nwidth; x++)
                {
                    float dc;   //  distance from center
                    float fp;   //  flux this pixel;
                    float sx,sy;
                    float vig;

                    sx=nwidth/2-x;
                    sy=nheight/2-y;

                    vig=nwidth;
                    vig=vig*ImageScalex;
                    //  need to make this account for actual pixel size
                    dc=sqrt(sx*sx*ImageScalex*ImageScalex+sy*sy*ImageScaley*ImageScaley);
                    //  now we have the distance from center, in arcseconds
                    //  now lets plot a gaussian falloff to the edges
                    //
                    float fa;
                    fa=exp(-2.0*0.7*(dc*dc)/vig/vig);

                    //  get the current value
                    fp=pt[0];

                    //  Add the sky glow
                    fp+=skyflux;

                    //  now scale it for the vignetting
                    fp=fa*fp;

                    //  clamp to limits
                    if(fp > maxval) fp=maxval;
                    if (fp > maxpix) maxpix = fp;
                    if (fp < minpix) minpix = fp;
                    //  and put it back
                    pt[0]=fp;
                    pt++;

                }
            }
        }


        //  Now we add some bias and read noise
        int subX = targetChip->getSubX() / targetChip->getBinX();
        int subY = targetChip->getSubY() / targetChip->getBinX();
        int subW = targetChip->getSubW() / targetChip->getBinX() + subX;
        int subH = targetChip->getSubH() / targetChip->getBinX() + subY;

        for(x=subX; x<subW; x++)
        {
            for(y=subY; y<subH; y++)
            {
                int noise;

                noise=random();
                noise=noise%maxnoise; //

                //IDLog("noise is %d\n", noise);
                AddToPixel(targetChip, x,y,bias+noise);
            }
        }


    } else {
        testvalue++;
        if(testvalue > 255) testvalue=0;
        val=testvalue;

        int nbuf    = targetChip->getSubW()*targetChip->getSubH();

        for(int x=0; x<nbuf; x++)
        {
            *ptr=val++;
            ptr++;
        }

    }
    return 0;
}

int CCDSim::DrawImageStar(CCDChip *targetChip, float mag,float x,float y)
{
    //float d;
    //float r;
    int sx,sy;
    int drew=0;
    int boxsizex=5;
    int boxsizey=5;
    float flux;
    float ExposureTime;

    int subX = targetChip->getSubX() / targetChip->getBinX();
    int subY = targetChip->getSubY() / targetChip->getBinX();
    int subW = targetChip->getSubW() / targetChip->getBinX() + subX;
    int subH = targetChip->getSubH() / targetChip->getBinX() + subY;

    if((x<subX)||(x>subW||(y<subY)||(y>subH)))
    {
        //  this star is not on the ccd frame anyways
        return 0;
    }

    if (targetChip->getXRes() == 500)
        ExposureTime = GuideExposureRequest*4;
    else
        ExposureTime = ExposureRequest;

    //  calculate flux from our zero point and gain values
    flux=pow(10,((mag-z)*k/-2.5));

    //  ok, flux represents one second now
    //  scale up linearly for exposure time
    flux=flux*ExposureTime;

    float qx;
    //  we need a box size that gives a radius at least 3 times fwhm
    qx=seeing/ImageScalex;
    qx=qx*3;
    boxsizex=(int)qx;
    boxsizex++;
    qx=seeing/ImageScaley;
    qx=qx*3;
    boxsizey=(int)qx;
    boxsizey++;

    //IDLog("BoxSize %d %d\n",boxsizex,boxsizey);


    for(sy=-boxsizey; sy<=boxsizey; sy++) {
        for(sx=-boxsizey; sx<=boxsizey; sx++) {
            int rc;
            float dc;   //  distance from center
            float fp;   //  flux this pixel;

            //  need to make this account for actual pixel size
            dc=sqrt(sx*sx*ImageScalex*ImageScalex+sy*sy*ImageScaley*ImageScaley);
            //  now we have the distance from center, in arcseconds
            //  This should be gaussian, but, for now we'll just go with
            //  a simple linear function
            float fa;
            fa=exp(-2.0*0.7*(dc*dc)/seeing/seeing);
            fp=fa*flux*targetChip->getBinX()*targetChip->getBinY();


            if(fp < 0) fp=0;

            rc=AddToPixel(targetChip, x+sx,y+sy,fp);
            if(rc != 0) drew=1;
        }
    }
    return drew;
}

int CCDSim::AddToPixel(CCDChip *targetChip, int x,int y,int val)
{
    int nwidth = targetChip->getSubW() / targetChip->getBinX();
    int nheight = targetChip->getSubH() / targetChip->getBinY();

    x -= targetChip->getSubX() / targetChip->getBinX();
    y -= targetChip->getSubY() / targetChip->getBinY();

    int drew=0;
    if(x >= 0) {
        if(x < nwidth) {
            if(y >= 0) {
                if(y < nheight) {
                    unsigned short *pt;
                    int newval;
                    drew++;

                    pt=(unsigned short int *)targetChip->getFrameBuffer();

                    pt+=(y*nwidth);
                    pt+=x;
                    newval=pt[0];
                    newval+=val;
                    if(newval > maxval) newval=maxval;
                    if (newval > maxpix) maxpix = newval;
                    if (newval < minpix) minpix = newval;
                    pt[0]=newval;
                }
            }
        }
    }
    return drew;
}

bool CCDSim::GuideNorth(float v)
{
    float c;

    c=v/1000*GuideRate;  //
    c=c/3600;
    decPE=decPE+c;

    return true;
}
bool CCDSim::GuideSouth(float v)
{
    float c;

    c=v/1000*GuideRate;  //
    c=c/3600;
    decPE=decPE-c;

    return true;
}

bool CCDSim::GuideEast(float v)
{
    float c;

    c=v/1000*GuideRate;
    c=c/3600.0/15.0;
    c=c/(cos(decPE*0.0174532925));
    raPE=raPE+c;

    return true;
}
bool CCDSim::GuideWest(float v)
{
    float c;

    c=v/1000*GuideRate;  //
    c=c/3600.0/15.0;
    c=c/(cos(decPE*0.0174532925));
    raPE=raPE-c;

    return true;
}

bool CCDSim::ISNewNumber (const char *dev, const char *name, double values[], char *names[], int n)
{
    //  first check if it's for our device
    //IDLog("INDI::CCD::ISNewNumber %s\n",name);
    if(strcmp(dev,getDeviceName())==0)
    {
        //  This is for our device
        //  Now lets see if it's something we process here

        //IDLog("CCDSim::ISNewNumber %s\n",name);
        if(strcmp(name,"SIMULATOR_SETTINGS")==0)
        {
            IUUpdateNumber(SimulatorSettingsNV, values, names, n);
            SimulatorSettingsNV->s=IPS_OK;

            //  Reset our parameters now
            SetupParms();
            IDSetNumber(SimulatorSettingsNV,NULL);
            saveConfig();

            //IDLog("Frame set to %4.0f,%4.0f %4.0f x %4.0f\n",CcdFrameN[0].value,CcdFrameN[1].value,CcdFrameN[2].value,CcdFrameN[3].value);
            //seeing=SimulatorSettingsN[0].value;
            return true;
        }

        if (strcmp(name, FilterSlotNP.name)==0)
        {
            processFilterSlot(getDeviceName(), values, names);
            return true;
        }


    }
    //  if we didn't process it, continue up the chain, let somebody else
    //  give it a shot
    return INDI::CCD::ISNewNumber(dev,name,values,names,n);
}


bool CCDSim::ISNewSwitch (const char *dev, const char *name, ISState *states, char *names[], int n)
{
    //IDLog("Enter IsNewSwitch for %s\n",name);
    //for(int x=0; x<n; x++) {
    //    IDLog("Switch %s %d\n",names[x],states[x]);
    //}

    if(strcmp(dev,getDeviceName())==0) {
        //  This one is for us


        if(strcmp(name,"ON_TIME_FACTOR")==0) {

            //  client is telling us what to do with co-ordinate requests
            TimeFactorSV->s=IPS_OK;
            IUUpdateSwitch(TimeFactorSV,states,names,n);
            //  Update client display
            IDSetSwitch(TimeFactorSV,NULL);

            saveConfig();
            if(TimeFactorS[0].s==ISS_ON    ) {
                //IDLog("CCDSim:: Time Factor 1\n");
                TimeFactor=1;
            }
            if(TimeFactorS[1].s==ISS_ON    ) {
                //IDLog("CCDSim:: Time Factor 0.1\n");
                TimeFactor=0.1;
            }
            if(TimeFactorS[2].s==ISS_ON    ) {
                //IDLog("CCDSim:: Time Factor 0.01\n");
                TimeFactor=0.01;
            }

            return true;
        }

    }

    //  Nobody has claimed this, so, ignore it
    return INDI::CCD::ISNewSwitch(dev,name,states,names,n);
}

void CCDSim::activeDevicesUpdated()
{
    IDSnoopDevice(ActiveDeviceT[0].text,"EQUATORIAL_PE");
    IDSnoopDevice(ActiveDeviceT[0].text,"TELESCOPE_INFO");
    IDSnoopDevice(ActiveDeviceT[1].text,"FWHM");

    strncpy(EqPENP.device, ActiveDeviceT[0].text, MAXINDIDEVICE);
    strncpy(ScopeParametersNP.device, ActiveDeviceT[0].text, MAXINDIDEVICE);
    strncpy(FWHMNP.device, ActiveDeviceT[1].text, MAXINDIDEVICE);
}

bool CCDSim::ISSnoopDevice (XMLEle *root)
{
     if (IUSnoopNumber(root,&FWHMNP)==0)
     {
           seeing = FWHMNP.np[0].value;

           if (isDebug())
                IDLog("CCD Simulator: New FWHM value of %g\n", seeing);
           return true;
     }

     if (IUSnoopNumber(root,&ScopeParametersNP)==0)
     {
           focallength = ScopeParametersNP.np[1].value;
           guider_focallength = ScopeParametersNP.np[3].value;
           if (isDebug())
           {
                IDLog("CCD Simulator: New focalLength value of %g\n", focallength);
                IDLog("CCD Simulator: New guider_focalLength value of %g\n", guider_focallength);
           }
           return true;
     }

     // We try to snoop EQPEC first, if not found, we snoop regular EQNP
     if(IUSnoopNumber(root,&EqPENP)==0)
     {
        double newra,newdec;
        newra=EqPEN[0].value;
        newdec=EqPEN[1].value;
        if((newra != raPE)||(newdec != decPE))
        {
             ln_equ_posn epochPos, J2000Pos;
             epochPos.ra   = newra*15.0;
             epochPos.dec  = newdec;


             ln_get_equ_prec2(&epochPos, ln_get_julian_from_sys(), JD2000, &J2000Pos);

             raPE  = J2000Pos.ra/15.0;
             decPE = J2000Pos.dec;

             usePE = true;

            if (isDebug())
                IDLog("raPE %g  decPE %g Snooped raPE %g  decPE %g\n",raPE,decPE,newra,newdec);

            return true;

        }
     }

     return INDI::CCD::ISSnoopDevice(root);
}

bool CCDSim::saveConfigItems(FILE *fp)
{
    INDI::CCD::saveConfigItems(fp);

    IUSaveConfigNumber(fp,SimulatorSettingsNV);
    IUSaveConfigSwitch(fp, TimeFactorSV);

    return true;
}

bool CCDSim::SelectFilter(int f)
{
    CurrentFilter = f;
    SelectFilterDone(f);
    return true;
}

bool CCDSim::GetFilterNames(const char* groupName)
{
    char filterName[MAXINDINAME];
    char filterLabel[MAXINDILABEL];
    int MaxFilter = FilterSlotN[0].max;

    const char *filterDesignation[5] = { "Red", "Green", "Blue", "H_Alpha", "Luminosity" };

    if (FilterNameT != NULL)
        delete FilterNameT;

    FilterNameT = new IText[MaxFilter];

    for (int i=0; i < MaxFilter; i++)
    {
        snprintf(filterName, MAXINDINAME, "FILTER_SLOT_NAME_%d", i+1);
        snprintf(filterLabel, MAXINDILABEL, "Filter #%d", i+1);
        IUFillText(&FilterNameT[i], filterName, filterLabel, filterDesignation[i]);
    }

    IUFillTextVector(FilterNameTP, FilterNameT, MaxFilter, getDeviceName(), "FILTER_NAME", "Filter names", groupName, IP_RW, 0, IPS_IDLE);

    return true;
}

int CCDSim::QueryFilter()
{
    return CurrentFilter;
}