Domenico Tiziani / gammalib

Commit 0fa57767a0f9c10de53327f2f1dfa41953e0cc12

Authored by knodlseder
1 parent 13954e0d

Compute DEADC from livetime and ontime in GCTAObservation::read_attributes (the … 

…DEADC keyword is not set correctly in the actual event lists)
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Showing 1 changed file with 29 additions and 15 deletions
inst/cta/src/GCTAObservation.cpp
  View file @0fa5776
... ... @@ -596,6 +596,7 @@ std::string GCTAObservation::print(void) const
596 596 result.append("\n"+parformat("Statistics")+statistics());
597 597 result.append("\n"+parformat("Ontime")+str(ontime()));
598 598 result.append("\n"+parformat("Livetime")+str(livetime()));
  599 + result.append("\n"+parformat("Deadtime correction")+str(deadc()));
599 600  
600 601 // Append pointing
601 602 if (m_pointing != NULL) {
... ... @@ -828,22 +829,25 @@ void GCTAObservation::free_members(void)
828 829 *
829 830 * Reads CTA observation attributes from HDU. Mandatory attributes are
830 831 *
831   - * RA_PNT - Right Ascension of pointing
832   - * DEC_PNT - Declination of pointing
  832 + * RA_PNT - Right Ascension of pointing
  833 + * DEC_PNT - Declination of pointing
  834 + * ONTIME - Exposure time
  835 + * LIVETIME - Livetime
833 836 *
834 837 * and optional attributes are
835 838 *
836 839 * OBJECT - Name of observed object
  840 + * DEADC - Deadtime correction
837 841 * RA_OBJ - Right Ascension of observed object,
838 842 * DEC_OBJ - Declination of observed object,
839 843 * OBS_ID - Observation identifier
840   - * LIVETIME - Livetime
841   - * DEADC - Deadtime correction
842 844 * ALT_PNT - Altitude of pointing above horizon
843 845 * AZ_PNT - Azimuth of pointing
844 846 *
845   - * Based on RA_PNT and DEC_PNT, the CTA pointing direction is set. Nothing
846   - * is done if the HDU pointer is NULL.
  847 + * Based on RA_PNT and DEC_PNT, the CTA pointing direction is set. Note that
  848 + * DEADC is computed using DEADC=LIVETIME/ONTIME
  849 + *
  850 + * Nothing is done if the HDU pointer is NULL.
847 851 *
848 852 * @todo The actual reader is a minimal reader to accomodate as many
849 853 * different datasets as possible. Once the CTA data format is fixed
... ... @@ -857,11 +861,11 @@ void GCTAObservation::read_attributes(const GFitsHDU* hdu)
857 861 // Read mandatory attributes
858 862 double ra_pnt = hdu->real("RA_PNT");
859 863 double dec_pnt = hdu->real("DEC_PNT");
  864 + m_ontime = (hdu->hascard("ONTIME")) ? hdu->real("ONTIME") : 0.0;
  865 + m_livetime = (hdu->hascard("LIVETIME")) ? hdu->real("LIVETIME") : 0.0;
860 866  
861 867 // Read optional attributes
862 868 m_name = (hdu->hascard("OBJECT")) ? hdu->string("OBJECT") : "unknown";
863   - m_ontime = (hdu->hascard("ONTIME")) ? hdu->real("ONTIME") : 0.0;
864   - m_livetime = (hdu->hascard("LIVETIME")) ? hdu->real("LIVETIME") : 0.0;
865 869 m_deadc = (hdu->hascard("DEADC")) ? hdu->real("DEADC") : 0.0;
866 870 m_ra_obj = (hdu->hascard("RA_OBJ")) ? hdu->real("RA_OBJ") : 0.0;
867 871 m_dec_obj = (hdu->hascard("DEC_OBJ")) ? hdu->real("DEC_OBJ") : 0.0;
... ... @@ -869,6 +873,16 @@ void GCTAObservation::read_attributes(const GFitsHDU* hdu)
869 873 double alt = (hdu->hascard("ALT_PNT")) ? hdu->real("ALT_PNT") : 0.0;
870 874 double az = (hdu->hascard("AZ_PNT")) ? hdu->real("AZ_PNT") : 0.0;
871 875  
  876 + // Kluge: compute DEADC from livetime and ontime instead of using the
  877 + // keyword value as the original event lists had this values badly
  878 + // assigned
  879 + if (m_ontime > 0) {
  880 + m_deadc = m_livetime / m_ontime;
  881 + }
  882 + else {
  883 + m_deadc = 0.0;
  884 + }
  885 +
872 886 // Set pointing information
873 887 GSkyDir pnt;
874 888 pnt.radec_deg(ra_pnt, dec_pnt);
... ... @@ -972,22 +986,22 @@ void GCTAObservation::write_attributes(GFitsHDU* hdu) const
972 986 * @param[in] model Gamma-ray source model.
973 987 *
974 988 * Implement the temporal integration as a simple multiplication by the
975   - * elapsed time. This assumes that the source is non-variable during the
  989 + * ontime. This assumes that the source is non-variable during the
976 990 * observation and that the CTA pointing is stable.
  991 + *
  992 + * Note that we use here the ontime as the GResponse::irf method returns
  993 + * already deadtime corrected response values.
977 994 ***************************************************************************/
978 995 double GCTAObservation::npred_temp(const GModel& model) const
979 996 {
980 997 // Initialise result
981 998 double result = 0.0;
982 999  
983   - // Determine ontime
984   - double ontime = events()->gti().ontime();
985   -
986 1000 // Integrate only if ontime is positive
987   - if (ontime > 0.0) {
  1001 + if (ontime() > 0.0) {
988 1002  
989   - // Integration is a simple multiplication by the time
990   - result = npred_spec(model, events()->gti().tstart()) * ontime;
  1003 + // Integration is a simple multiplication by the ontime
  1004 + result = npred_spec(model, events()->gti().tstart()) * ontime();
991 1005  
992 1006 }
993 1007  
... ...