From d54fe7c1f704a63824c5bfa0ece65245572e9b27 Mon Sep 17 00:00:00 2001
From: Joseph Hunkeler <jhunkeler@gmail.com>
Date: Wed, 4 Mar 2015 21:21:30 -0500
Subject: Initial commit

---
 src/libcf/cf_electronics_dead_time.c | 104 +++++++++++++++++++++++++++++++++++
 1 file changed, 104 insertions(+)
 create mode 100644 src/libcf/cf_electronics_dead_time.c

(limited to 'src/libcf/cf_electronics_dead_time.c')

diff --git a/src/libcf/cf_electronics_dead_time.c b/src/libcf/cf_electronics_dead_time.c
new file mode 100644
index 0000000..38c2219
--- /dev/null
+++ b/src/libcf/cf_electronics_dead_time.c
@@ -0,0 +1,104 @@
+/*****************************************************************************
+ *              Johns Hopkins University
+ *              Center For Astrophysical Sciences
+ *              FUSE
+ *****************************************************************************
+ *
+ * Synopsis:    cf_electronics_dead_time(fitsfile *header, long nseconds,
+ *                                      float *fec_rate, float *elec_dtc)
+ *
+ * Description: Scales the weighting factor to correct for the electronics
+ *              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     *fec_rate     An array of Front End Counter (FEC)
+ *                                      rates
+ *              float     *elec_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   Corrected function description and
+ *                                      added cf_timestamp after ELEC_COR
+ *                                      check.
+ *		12/06/02   1.4    wvd   Calculate DT correction for each time
+ *					step, then apply to photons.
+ *					Set keyword DET_DEAD.
+ *              05/20/03   1.5    rdr   Added proc_check call
+ *              08/01/03   1.7    wvd   Just calculate correction; don't
+ *                                      apply it.  Return elec_dtc array.
+ *              08/04/03   1.8    wvd   Convert fec_rate to type short.
+ *              11/26/03   1.9    wvd   Change fec_rate to type float.
+ *              02/12/04   1.10   wvd   In verbose mode, write mean DTC.
+ *              04/07/07   1.11   wvd   Clean up compiler warnings.
+ *
+ ****************************************************************************/
+
+#include <string.h>
+#include <math.h>
+#include "calfuse.h"
+
+int
+cf_electronics_dead_time(fitsfile *header, long nseconds, 
+			 float *fec_rate, float *elec_dtc)
+{
+    char CF_PRGM_ID[] = "cf_electronics_dead_time";
+    char CF_VER_NUM[] = "1.11";
+
+    char  elecfile[FLEN_VALUE]={"\0"}, detector[FLEN_VALUE]={"\0"};
+    char  keyword[FLEN_KEYWORD]={"\0"};
+    int   errflg=0, status=0;
+    long  k;
+    float abort, clock, state;
+    float mean_elec_dtc = 0.;
+    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;
+
+    FITS_read_key(header, TSTRING, "DETECTOR", detector, NULL, &status);
+    /*
+     *  Get the electronics dead-time constants.
+     */
+    FITS_read_key(header, TSTRING, "ELEC_CAL", elecfile, NULL, &status);
+    FITS_open_file(&elecfits, cf_cal_file(elecfile), READONLY, &status);
+    sprintf(keyword, "ABORT_%s", detector);
+    FITS_read_key(elecfits, TFLOAT, keyword, &abort, NULL, &status);
+    sprintf(keyword, "CLOCK_%s", detector);
+    FITS_read_key(elecfits, TFLOAT, keyword, &clock, NULL, &status);
+    sprintf(keyword, "STATE_%s", detector);
+    FITS_read_key(elecfits, TFLOAT, keyword, &state, NULL, &status);
+    FITS_close_file(elecfits, &status);
+    /*
+     *  Calculate dead-time correction.
+     */
+    for (k=0; k<nseconds; k++) {
+        float xa, x, x2, x4, x6, x10;
+
+        xa = exp(-fec_rate[k]*abort);
+        x  = exp(-fec_rate[k]*clock);
+        x2 = x*x;
+        x4 = x2*x2;
+        x6 = x4*x2;
+        x10 = x6*x4;
+
+        elec_dtc[k] = (1. + fec_rate[k]*state + 4.*(x2-x) + x6 - x10)/xa;
+        if (elec_dtc[k] < 1.0) elec_dtc[k] = 1.0;
+	mean_elec_dtc += elec_dtc[k];
+    }
+    /*
+     *  Calculate mean dead-time correction.  Write to file header.
+     */
+    mean_elec_dtc /= nseconds;
+    cf_verbose(2, "Mean detector electronics dead-time correction: %f", mean_elec_dtc);
+    FITS_update_key(header, TFLOAT, "DET_DEAD", &mean_elec_dtc, NULL, &status);
+
+    cf_proc_update(header, CF_PRGM_ID, "COMPLETE");
+    cf_timestamp(CF_PRGM_ID, CF_VER_NUM, "Done processing");
+    return 0;
+}
-- 
cgit