REAL8 calculate_ligo_snr_from_strain_real8( REAL8TimeSeries *strain,
const CHAR ifo[3])
{
REAL8 ret = -1, snrSq, freq, psdValue;
REAL8 deltaF;
REAL8FFTPlan *pfwd;
COMPLEX16FrequencySeries *fftData;
UINT4 k;
/* create the time series */
deltaF = strain->deltaT * strain->data->length;
fftData = XLALCreateCOMPLEX16FrequencySeries( strain->name, &(strain->epoch),
0, deltaF, &lalDimensionlessUnit,
strain->data->length/2 + 1 );
/* perform the fft */
pfwd = XLALCreateForwardREAL8FFTPlan( strain->data->length, 0 );
XLALREAL8TimeFreqFFT( fftData, strain, pfwd );
/* compute the SNR for initial LIGO at design */
for ( snrSq = 0, k = 0; k < fftData->data->length; k++ )
{
freq = fftData->deltaF * k;
if ( ifo[0] == 'V' )
{
if (freq < 35)
continue;
LALVIRGOPsd( NULL, &psdValue, freq );
psdValue /= 9e-46;
}
else
{
if (freq < 40)
continue;
LALLIGOIPsd( NULL, &psdValue, freq );
}
fftData->data->data[k] /= 3e-23;
snrSq += creal(fftData->data->data[k]) * creal(fftData->data->data[k]) / psdValue;
snrSq += cimag(fftData->data->data[k]) * cimag(fftData->data->data[k]) / psdValue;
}
snrSq *= 4*fftData->deltaF;
XLALDestroyREAL8FFTPlan( pfwd );
XLALDestroyCOMPLEX16FrequencySeries( fftData );
ret = sqrt(snrSq);
return ret;
}
static PyObject *pylal_XLALREAL8TimeFreqFFT(PyObject *self, PyObject *args)
{
pylal_COMPLEX16FrequencySeries *fser;
pylal_REAL8TimeSeries *tser;
pylal_REAL8FFTPlan *plan;
if(!PyArg_ParseTuple(args, "O!O!O!", &pylal_COMPLEX16FrequencySeries_Type, &fser, &pylal_REAL8TimeSeries_Type, &tser, &pylal_REAL8FFTPlan_Type, &plan))
return NULL;
if(XLALREAL8TimeFreqFFT(fser->series, tser->series, plan->plan)) {
pylal_set_exception_from_xlalerrno();
return NULL;
}
Py_INCREF(Py_None);
return Py_None;
}
/* creates a waveform in the frequency domain; the waveform might be generated
* in the time-domain and transformed */
int create_fd_waveform(COMPLEX16FrequencySeries ** htilde_plus, COMPLEX16FrequencySeries ** htilde_cross, struct params p)
{
clock_t timer_start = 0;
double chirplen, deltaF;
int chirplen_exp;
/* length of the chirp in samples */
chirplen = imr_time_bound(p.f_min, p.m1, p.m2, p.s1z, p.s2z) * p.srate;
/* make chirplen next power of two */
frexp(chirplen, &chirplen_exp);
chirplen = ldexp(1.0, chirplen_exp);
deltaF = p.srate / chirplen;
if (p.verbose)
fprintf(stderr, "using frequency resolution deltaF = %g Hz\n", deltaF);
if (p.condition) {
if (p.verbose) {
fprintf(stderr, "generating waveform in frequency domain using XLALSimInspiralFD...\n");
timer_start = clock();
}
XLALSimInspiralFD(htilde_plus, htilde_cross, p.m1, p.m2, p.s1x, p.s1y, p.s1z, p.s2x, p.s2y, p.s2z, p.distance, p.inclination, p.phiRef, p.longAscNodes, p.eccentricity, p.meanPerAno, deltaF, p.f_min, 0.5 * p.srate, p.fRef, p.params, p.approx);
if (p.verbose)
fprintf(stderr, "generation took %g seconds\n", (double)(clock() - timer_start) / CLOCKS_PER_SEC);
} else if (p.domain == LAL_SIM_DOMAIN_FREQUENCY) {
if (p.verbose) {
fprintf(stderr, "generating waveform in frequency domain using XLALSimInspiralChooseFDWaveform...\n");
timer_start = clock();
}
XLALSimInspiralChooseFDWaveform(htilde_plus, htilde_cross, p.m1, p.m2, p.s1x, p.s1y, p.s1z, p.s2x, p.s2y, p.s2z, p.distance, p.inclination, p.phiRef, p.longAscNodes, p.eccentricity, p.meanPerAno, deltaF, p.f_min, 0.5 * p.srate, p.fRef, p.params, p.approx);
if (p.verbose)
fprintf(stderr, "generation took %g seconds\n", (double)(clock() - timer_start) / CLOCKS_PER_SEC);
} else {
REAL8TimeSeries *h_plus = NULL;
REAL8TimeSeries *h_cross = NULL;
REAL8FFTPlan *plan;
/* generate time domain waveform */
if (p.verbose) {
fprintf(stderr, "generating waveform in time domain using XLALSimInspiralChooseTDWaveform...\n");
timer_start = clock();
}
XLALSimInspiralChooseTDWaveform(&h_plus, &h_cross, p.m1, p.m2, p.s1x, p.s1y, p.s1z, p.s2x, p.s2y, p.s2z, p.distance, p.inclination, p.phiRef, p.longAscNodes, p.eccentricity, p.meanPerAno, 1.0 / p.srate, p.f_min, p.fRef, p.params, p.approx);
if (p.verbose)
fprintf(stderr, "generation took %g seconds\n", (double)(clock() - timer_start) / CLOCKS_PER_SEC);
/* resize the waveforms to the required length */
XLALResizeREAL8TimeSeries(h_plus, h_plus->data->length - (size_t) chirplen, (size_t) chirplen);
XLALResizeREAL8TimeSeries(h_cross, h_cross->data->length - (size_t) chirplen, (size_t) chirplen);
/* put the waveform in the frequency domain */
/* (the units will correct themselves) */
if (p.verbose) {
fprintf(stderr, "transforming waveform to frequency domain...\n");
timer_start = clock();
}
*htilde_plus = XLALCreateCOMPLEX16FrequencySeries("htilde_plus", &h_plus->epoch, 0.0, deltaF, &lalDimensionlessUnit, (size_t) chirplen / 2 + 1);
*htilde_cross = XLALCreateCOMPLEX16FrequencySeries("htilde_cross", &h_cross->epoch, 0.0, deltaF, &lalDimensionlessUnit, (size_t) chirplen / 2 + 1);
plan = XLALCreateForwardREAL8FFTPlan((size_t) chirplen, 0);
XLALREAL8TimeFreqFFT(*htilde_cross, h_cross, plan);
XLALREAL8TimeFreqFFT(*htilde_plus, h_plus, plan);
if (p.verbose)
fprintf(stderr, "transformation took %g seconds\n", (double)(clock() - timer_start) / CLOCKS_PER_SEC);
/* clean up */
XLALDestroyREAL8FFTPlan(plan);
XLALDestroyREAL8TimeSeries(h_cross);
XLALDestroyREAL8TimeSeries(h_plus);
}
return 0;
}
REAL8 calculate_snr_from_strain_and_psd_real8( REAL8TimeSeries *strain,
REAL8FrequencySeries *psd,
REAL8 startFreq,
const CHAR ifo[3])
{
REAL8 ret = -1, snrSq, freq, psdValue;
REAL8 deltaF;
REAL8FFTPlan *pfwd;
COMPLEX16FrequencySeries *fftData;
UINT4 k;
/* create the time series */
deltaF = strain->deltaT * strain->data->length;
fftData = XLALCreateCOMPLEX16FrequencySeries( strain->name, &(strain->epoch),
0, deltaF, &lalDimensionlessUnit,
strain->data->length/2 + 1 );
/* perform the fft */
pfwd = XLALCreateForwardREAL8FFTPlan( strain->data->length, 0 );
XLALREAL8TimeFreqFFT( fftData, strain, pfwd );
/* The PSD, if provided, comes in as it was in the original file */
/* since we don't know deltaF until we get here. Interpolate now */
if ( psd )
{
psd = XLALInterpolatePSD(psd, 1.0 / deltaF);
}
/* compute the SNR for initial LIGO at design */
for ( snrSq = 0, k = 0; k < fftData->data->length; k++ )
{
freq = fftData->deltaF * k;
if ( psd )
{
if ( freq < startFreq || k > psd->data->length )
continue;
psdValue = psd->data->data[k];
psdValue /= 9e-46;
}
else if ( ifo[0] == 'V' )
{
if (freq < 35)
continue;
LALVIRGOPsd( NULL, &psdValue, freq );
psdValue /= 9e-46;
}
else
{
if (freq < 40)
continue;
LALLIGOIPsd( NULL, &psdValue, freq );
}
fftData->data->data[k] /= 3e-23;
snrSq += creal(fftData->data->data[k]) * creal(fftData->data->data[k]) / psdValue;
snrSq += cimag(fftData->data->data[k]) * cimag(fftData->data->data[k]) / psdValue;
}
snrSq *= 4*fftData->deltaF;
XLALDestroyREAL8FFTPlan( pfwd );
XLALDestroyCOMPLEX16FrequencySeries( fftData );
if ( psd )
XLALDestroyREAL8FrequencySeries( psd );
ret = sqrt(snrSq);
printf("Obtained snr=%f\n", ret);
return ret;
}
REAL8 calculate_lalsim_snr(SimInspiralTable *inj, char *IFOname, REAL8FrequencySeries *psd, REAL8 start_freq)
{
/* Calculate and return the single IFO SNR
*
* Required options:
*
* inj: SimInspiralTable entry for which the SNR has to be calculated
* IFOname: The canonical name (e.g. H1, L1, V1) name of the IFO for which the SNR must be calculated
* PSD: PSD curve to be used for the overlap integrap
* start_freq: lower cutoff of the overlap integral
*
* */
int ret=0;
INT4 errnum=0;
UINT4 j=0;
/* Fill detector site info */
LALDetector* detector=NULL;
detector=calloc(1,sizeof(LALDetector));
if(!strcmp(IFOname,"H1"))
memcpy(detector,&lalCachedDetectors[LALDetectorIndexLHODIFF],sizeof(LALDetector));
if(!strcmp(IFOname,"H2"))
memcpy(detector,&lalCachedDetectors[LALDetectorIndexLHODIFF],sizeof(LALDetector));
if(!strcmp(IFOname,"LLO")||!strcmp(IFOname,"L1"))
memcpy(detector,&lalCachedDetectors[LALDetectorIndexLLODIFF],sizeof(LALDetector));
if(!strcmp(IFOname,"V1")||!strcmp(IFOname,"VIRGO"))
memcpy(detector,&lalCachedDetectors[LALDetectorIndexVIRGODIFF],sizeof(LALDetector));
Approximant approx=TaylorF2;
approx=XLALGetApproximantFromString(inj->waveform);
LALSimulationDomain modelDomain;
if(XLALSimInspiralImplementedFDApproximants(approx)) modelDomain = LAL_SIM_DOMAIN_FREQUENCY;
else if(XLALSimInspiralImplementedTDApproximants(approx)) modelDomain = LAL_SIM_DOMAIN_TIME;
else
{
fprintf(stderr,"ERROR. Unknown approximant number %i. Unable to choose time or frequency domain model.",approx);
exit(1);
}
REAL8 m1,m2, s1x,s1y,s1z,s2x,s2y,s2z,phi0,f_min,f_max,iota,polarization;
/* No tidal PN terms until injtable is able to get them */
LALDict *LALpars= XLALCreateDict();
/* Spin and tidal interactions at the highest level (default) until injtable stores them.
* When spinO and tideO are added to injtable we can un-comment those lines and should be ok
*
int spinO = inj->spinO;
int tideO = inj->tideO;
XLALSimInspiralSetSpinOrder(waveFlags, *(LALSimInspiralSpinOrder*) spinO);
XLALSimInspiralSetTidalOrder(waveFlags, *(LALSimInspiralTidalOrder*) tideO);
*/
XLALSimInspiralWaveformParamsInsertPNPhaseOrder(LALpars,XLALGetOrderFromString(inj->waveform));
XLALSimInspiralWaveformParamsInsertPNAmplitudeOrder(LALpars,inj->amp_order);
/* Read parameters */
m1=inj->mass1*LAL_MSUN_SI;
m2=inj->mass2*LAL_MSUN_SI;
s1x=inj->spin1x;
s1y=inj->spin1y;
s1z=inj->spin1z;
s2x=inj->spin2x;
s2y=inj->spin2y;
s2z=inj->spin2z;
iota=inj->inclination;
f_min=XLALSimInspiralfLow2fStart(inj->f_lower,XLALSimInspiralWaveformParamsLookupPNAmplitudeOrder(LALpars),XLALGetApproximantFromString(inj->waveform));
phi0=inj->coa_phase;
polarization=inj->polarization;
REAL8 latitude=inj->latitude;
REAL8 longitude=inj->longitude;
LIGOTimeGPS epoch;
memcpy(&epoch,&(inj->geocent_end_time),sizeof(LIGOTimeGPS));
/* Hardcoded values of srate and segment length. If changed here they must also be changed in inspinj.c */
REAL8 srate=4096.0;
const CHAR *WF=inj->waveform;
/* Increase srate for EOB WFs */
if (strstr(WF,"EOB"))
srate=8192.0;
REAL8 segment=64.0;
f_max=(srate/2.0-(1.0/segment));
size_t seglen=(size_t) segment*srate;
REAL8 deltaF=1.0/segment;
REAL8 deltaT=1.0/srate;
/* Frequency domain h+ and hx. They are going to be filled either by a FD WF or by the FFT of a TD WF*/
COMPLEX16FrequencySeries *freqHplus;
COMPLEX16FrequencySeries *freqHcross;
freqHplus= XLALCreateCOMPLEX16FrequencySeries("fhplus",
&epoch,
0.0,
deltaF,
&lalDimensionlessUnit,
seglen/2+1
);
freqHcross=XLALCreateCOMPLEX16FrequencySeries("fhcross",
&epoch,
0.0,
deltaF,
&lalDimensionlessUnit,
seglen/2+1
);
/* If the approximant is on the FD call XLALSimInspiralChooseFDWaveform */
if (modelDomain == LAL_SIM_DOMAIN_FREQUENCY)
{
COMPLEX16FrequencySeries *hptilde=NULL;
COMPLEX16FrequencySeries *hctilde=NULL;
//We do not pass the polarization here, we assume it is taken into account when projecting h+,x onto the detector.
XLAL_TRY(ret=XLALSimInspiralChooseFDWaveform(&hptilde,&hctilde, m1, m2,
s1x, s1y, s1z, s2x, s2y, s2z,
LAL_PC_SI * 1.0e6, iota, phi0, 0., 0., 0.,
deltaF, f_min, 0.0, 0.0,
LALpars,approx),errnum);
XLALDestroyDict(LALpars);
if(!hptilde|| hptilde->data==NULL || hptilde->data->data==NULL ||!hctilde|| hctilde->data==NULL || hctilde->data->data==NULL)
{
XLALPrintError(" ERROR in XLALSimInspiralChooseFDWaveform(): error generating waveform. errnum=%d. Exiting...\n",errnum );
exit(1);
}
COMPLEX16 *dataPtr = hptilde->data->data;
for (j=0; j<(UINT4) freqHplus->data->length; ++j)
{
if(j < hptilde->data->length)
{
freqHplus->data->data[j] = dataPtr[j];
}
else
{
freqHplus->data->data[j]=0.0 + I*0.0;
}
}
dataPtr = hctilde->data->data;
for (j=0; j<(UINT4) freqHplus->data->length; ++j)
{
if(j < hctilde->data->length)
{
freqHcross->data->data[j] = dataPtr[j];
}
else
{
freqHcross->data->data[j]=0.0+0.0*I;
}
}
/* Clean */
if(hptilde) XLALDestroyCOMPLEX16FrequencySeries(hptilde);
if(hctilde) XLALDestroyCOMPLEX16FrequencySeries(hctilde);
}
else
{
/* Otherwise use XLALSimInspiralChooseTDWaveform */
REAL8FFTPlan *timeToFreqFFTPlan = XLALCreateForwardREAL8FFTPlan((UINT4) seglen, 0 );
REAL8TimeSeries *hplus=NULL;
REAL8TimeSeries *hcross=NULL;
REAL8TimeSeries *timeHplus=NULL;
REAL8TimeSeries *timeHcross=NULL;
REAL8 padding =0.4;//seconds
REAL8Window *window=XLALCreateTukeyREAL8Window(seglen,(REAL8)2.0*padding*srate/(REAL8)seglen);
REAL4 WinNorm = sqrt(window->sumofsquares/window->data->length);
timeHcross=XLALCreateREAL8TimeSeries("timeModelhCross",
&epoch,
0.0,
deltaT,
&lalStrainUnit,
seglen
);
timeHplus=XLALCreateREAL8TimeSeries("timeModelhplus",
&epoch,
0.0,
deltaT,
&lalStrainUnit,
seglen
);
for (j=0;j<(UINT4) timeHcross->data->length;++j)
timeHcross->data->data[j]=0.0;
for (j=0;j<(UINT4) timeHplus->data->length;++j)
timeHplus->data->data[j]=0.0;
XLAL_TRY(ret=XLALSimInspiralChooseTDWaveform(&hplus, &hcross, m1, m2,
s1x, s1y, s1z, s2x, s2y, s2z,
LAL_PC_SI*1.0e6, iota,
phi0, 0., 0., 0., deltaT, f_min, 0.,
LALpars, approx),
errnum);
if (ret == XLAL_FAILURE || hplus == NULL || hcross == NULL)
{
XLALPrintError(" ERROR in XLALSimInspiralChooseTDWaveform(): error generating waveform. errnum=%d. Exiting...\n",errnum );
exit(1);
}
hplus->epoch = timeHplus->epoch;
hcross->epoch = timeHcross->epoch;
XLALSimAddInjectionREAL8TimeSeries(timeHplus, hplus, NULL);
XLALSimAddInjectionREAL8TimeSeries(timeHcross, hcross, NULL);
for (j=0; j<(UINT4) timeHplus->data->length; ++j)
timeHplus->data->data[j]*=window->data->data[j];
for (j=0; j<(UINT4) timeHcross->data->length; ++j)
timeHcross->data->data[j]*=window->data->data[j];
for (j=0; j<(UINT4) freqHplus->data->length; ++j)
{
freqHplus->data->data[j]=0.0+I*0.0;
freqHcross->data->data[j]=0.0+I*0.0;
}
/* FFT into freqHplus and freqHcross */
XLALREAL8TimeFreqFFT(freqHplus,timeHplus,timeToFreqFFTPlan);
XLALREAL8TimeFreqFFT(freqHcross,timeHcross,timeToFreqFFTPlan);
for (j=0; j<(UINT4) freqHplus->data->length; ++j)
{
freqHplus->data->data[j]/=WinNorm;
freqHcross->data->data[j]/=WinNorm;
}
/* Clean... */
if ( hplus ) XLALDestroyREAL8TimeSeries(hplus);
if ( hcross ) XLALDestroyREAL8TimeSeries(hcross);
if ( timeHplus ) XLALDestroyREAL8TimeSeries(timeHplus);
if ( timeHcross ) XLALDestroyREAL8TimeSeries(timeHcross);
if (timeToFreqFFTPlan) LALFree(timeToFreqFFTPlan);
if (window) XLALDestroyREAL8Window(window);
}
/* The WF has been generated and is in freqHplus/cross. Now project into the IFO frame */
double Fplus, Fcross;
double FplusScaled, FcrossScaled;
double HSquared;
double GPSdouble=(REAL8) inj->geocent_end_time.gpsSeconds+ (REAL8) inj->geocent_end_time.gpsNanoSeconds*1.0e-9;
double gmst;
LIGOTimeGPS GPSlal;
XLALGPSSetREAL8(&GPSlal, GPSdouble);
gmst=XLALGreenwichMeanSiderealTime(&GPSlal);
/* Fill Fplus and Fcross*/
XLALComputeDetAMResponse(&Fplus, &Fcross, (const REAL4 (*)[3])detector->response,longitude, latitude, polarization, gmst);
/* And take the distance into account */
FplusScaled = Fplus / (inj->distance);
FcrossScaled = Fcross / (inj->distance);
REAL8 timedelay = XLALTimeDelayFromEarthCenter(detector->location,longitude, latitude, &GPSlal);
REAL8 timeshift = timedelay;
REAL8 twopit = LAL_TWOPI * timeshift;
UINT4 lower = (UINT4)ceil(start_freq / deltaF);
UINT4 upper = (UINT4)floor(f_max / deltaF);
REAL8 re = cos(twopit*deltaF*lower);
REAL8 im = -sin(twopit*deltaF*lower);
/* Incremental values, using cos(theta) - 1 = -2*sin(theta/2)^2 */
REAL8 dim = -sin(twopit*deltaF);
REAL8 dre = -2.0*sin(0.5*twopit*deltaF)*sin(0.5*twopit*deltaF);
REAL8 TwoDeltaToverN = 2.0 *deltaT / ((double) seglen);
REAL8 plainTemplateReal, plainTemplateImag,templateReal,templateImag;
REAL8 newRe, newIm,temp;
REAL8 this_snr=0.0;
if ( psd )
{
psd = XLALInterpolatePSD(psd, deltaF);
}
for (j=lower; j<=(UINT4) upper; ++j)
{
/* derive template (involving location/orientation parameters) from given plus/cross waveforms: */
plainTemplateReal = FplusScaled * creal(freqHplus->data->data[j])
+ FcrossScaled *creal(freqHcross->data->data[j]);
plainTemplateImag = FplusScaled * cimag(freqHplus->data->data[j])
+ FcrossScaled * cimag(freqHcross->data->data[j]);
/* do time-shifting... */
/* (also un-do 1/deltaT scaling): */
templateReal = (plainTemplateReal*re - plainTemplateImag*im) / deltaT;
templateImag = (plainTemplateReal*im + plainTemplateImag*re) / deltaT;
HSquared = templateReal*templateReal + templateImag*templateImag ;
temp = ((TwoDeltaToverN * HSquared) / psd->data->data[j]);
this_snr += temp;
/* Now update re and im for the next iteration. */
newRe = re + re*dre - im*dim;
newIm = im + re*dim + im*dre;
re = newRe;
im = newIm;
}
/* Clean */
if (freqHcross) XLALDestroyCOMPLEX16FrequencySeries(freqHcross);
if (freqHplus) XLALDestroyCOMPLEX16FrequencySeries(freqHplus);
if (detector) free(detector);
return sqrt(this_snr*2.0);
}
