Initial commit

1 files changed, 109 insertions, 0 deletions

diff --git a/src/libcf/cf_ids_dead_time.c b/src/libcf/cf_ids_dead_time.c
new file mode 100644
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+++ b/src/libcf/cf_ids_dead_time.c
@@ -0,0 +1,109 @@
+/*****************************************************************************
+ *              Johns Hopkins University
+ *              Center For Astrophysical Sciences
+ *              FUSE
+ *****************************************************************************
+ *
+ * Synopsis:    cf_ids_dead_time(fitsfile *header, long nseconds,
+ *                               float *aic_rate, float *ids_dtc)
+ *
+ * Description: Computes the weighting factor needed to correct
+ *		for the IDS dead time.
+ *
+ * Arguments:   fitsfile  *header       Pointer to FITS file containing the
+ *                                      header of the intermediate data file
+ *              long      nseconds      The number of timeline values
+ *              float     *aic_rate     An array of Active Image Counter
+ *                                      values
+ *              float     *ids_dtc      Dead-time correction array (returned)
+ *
+ * Calls:
+ *
+ * Return:      0  on success
+ *
+ * History:     10/27/02   1.1    peb   Begin work
+ *              11/11/02   1.2    peb   Correct function description and add
+ *                                      cf_timestamp after IDS__COR check.
+ *              12/09/02   1.4    wvd   Calculate DT correction for each time
+ *                                      step, then apply to photons.
+ *                                      Set keyword IDS_DEAD.
+ *              05/20/03   1.5    rdr   Add proc_check call.
+ *		08/01/03   1.8    wvd   Just calculate correction; don't
+ *					apply it.  Return ids_dtc array.
+ *		08/04/03   1.9    wvd   Convert aic_rate to type short.
+ *		11/26/03   1.10   wvd   Convert aic_rate to type float.
+ *		02/09/04   1.11   wvd   max_ids_rate depends on instrument
+ *					mode. For TTAG data, include time
+ *					stamps in aic_rate.
+ *		04/07/07   1.12   wvd   Clean up compiler warnings.
+ *
+ ****************************************************************************/
+
+#include <string.h>
+#include "calfuse.h"
+
+int
+cf_ids_dead_time(fitsfile *header, long nseconds, float *aic_rate,
+	float *ids_dtc)
+{
+    char CF_PRGM_ID[] = "cf_ids_dead_time";
+    char CF_VER_NUM[] = "1.12";
+
+    char elecfile[FLEN_VALUE], instmode[FLEN_VALUE];
+    int  errflg=0, status=0;
+    long  k;
+    float ids_rate, tstamps, ttperiod;
+    float mean_ids_dtc = 0.;
+    float max_ids_rate = 1.;
+    fitsfile *elecfits;
+
+    cf_error_init(CF_PRGM_ID, CF_VER_NUM, stderr);
+    cf_timestamp(CF_PRGM_ID, CF_VER_NUM, "Begin Processing");
+    if ((errflg = cf_proc_check(header, CF_PRGM_ID))) return errflg;
+    /*
+     *  Read observing mode and interval between time stamps.
+     */
+    FITS_read_key(header, TSTRING, "INSTMODE", instmode, NULL, &status);
+    FITS_read_key(header, TFLOAT, "TTPERIOD", &ttperiod, NULL, &status);
+    /*
+     *  Compute number of time stamps per second (0 for HIST data).
+     */
+    if (!strncmp(instmode, "TTAG", 4)) 		/* TTAG MODE */
+	if (ttperiod > 1e-8) tstamps = 1./ttperiod;
+	else tstamps = 1.;
+    else					/* HIST MODE */
+	tstamps = 0.;
+    /*
+     *  Maximum IDS rate depends on instrument mode.
+     */
+    FITS_read_key(header, TSTRING, "ELEC_CAL", elecfile, NULL, &status);
+    FITS_open_file(&elecfits, cf_cal_file(elecfile), READONLY, &status);
+    if (!strncmp(instmode, "TTAG", 4)) 
+        FITS_read_key(elecfits, TFLOAT, "TTAG_BUS", &max_ids_rate, NULL, &status);
+    else
+        FITS_read_key(elecfits, TFLOAT, "HIST_BUS", &max_ids_rate, NULL, &status);
+    FITS_close_file(elecfits, &status);
+    cf_verbose(4, "max_ids_rate = %f", max_ids_rate);
+    /*
+     *  Calculate the IDS dead-time correction.
+     */
+    for (k=0; k<nseconds; k++) {
+        ids_rate = aic_rate[k] + tstamps;
+
+	if (ids_rate > max_ids_rate)
+	    ids_dtc[k] = ids_rate/max_ids_rate;
+	else
+	    ids_dtc[k] = 1.0;
+        mean_ids_dtc += ids_dtc[k];
+    }
+    /*
+     *  Write mean IDS dead-time correction to file header.
+     */
+    mean_ids_dtc /= nseconds;
+    cf_verbose(2, "Mean IDS dead-time correction: %f", mean_ids_dtc);
+    FITS_update_key(header, TFLOAT, "IDS_DEAD", &mean_ids_dtc, NULL, &status);
+
+    cf_proc_update(header, CF_PRGM_ID, "COMPLETE");
+    cf_timestamp(CF_PRGM_ID, CF_VER_NUM, "Done processing");
+    return 0;
+}