7.7 SDR_SUM

     

This procedure sums an array of IGORE SDRs into an output SDR. The format of this command is:

Calling Sequence
SDR_SUM, in_sdr, out_sdr

Arguments

IN_SDR:

Array of one or more Igore SDR records which have HDR, DAT, and ERR fields. The SDB header must be loaded, this routine will load others as needed.

OUT_SDR:

A single SDR in which to store the sum of the input SDRs. OUT_SDR must exist on call. It is returned with HDR, DATA, ERR, EDG, and WID fields populated.

Keywords

AUX:

Input string specifying list AUX data types required to be in the input SDRs. Warning messages are printed if these data types are not in input SDRs. NOTE: Currently supports only CRCs.

/BYCFG:

Input switch which if present and nonzero, specifies that summing should be performed for each unique detector configuration. Default is single sum of available data.

/BYDAY:

Input switch which if present and nonzero, specifies that summing should be performed for each (approximate) daily interval. Default is single sum of available data.

/BYDET:

Input switch which if present and nonzero, specifies that summing should be performed by detector. Default is a single sum of available data.

/BYDSA:

Input switch which if present and nonzero, specifies that summing should be perfomed by detector step angle or source aspect. By default, all SDRs are summed into a single sum. The keyword SUM must be set along with BYDSA to create individual SDRs for each step angle. BYSCAN overrides BYDSA and a warning is issued. The combination of BYDSA and BYDET will create a #dsa by #det element SDR array.

/BYSCAN:

Input logical which if present and nonzero, specifies that summing should be perfomed by target scan angle (HDR.TARGSCAN) or source aspect. By default, all SDRs are summed into a single sum. The keyword SUM must be set along with BYSCAN to create individual SDRs for each scan angle. BYSCAN overrides BYDSA and a warning is issued. The combination of BYSCAN and BYDET will create a #scan by #det element SDR array. NOTE: TARGSCANS are rounded to 0.2 degrees to find unique ranges.

COR_MATRX:

Output IDL structure containing the correlation matrix.

CRC_SUM:

Output IDL structure containing the resultant CRCs from the sum.

EDGES:

Input float array which specifies the lower edges (MeV) of the output channels. Overrides default gain computation. Must have same dimensions as DAT field in SDR.

/MATRIX:

Input switch, which if present and nonzero, causes summing of response matrices in input SDRs to be performed and stored in output SDRs.

/RELSPEC:

Input switch which if present and nonzero, specifies that RELSPEC records should be added to input SDR. The RELSPEC records document the file name and tagword of the file and SDR containing the summed data.

/VERBOSE:

Logical switch specifying that information messages should be displayed. Default is not to display information messages.

WEIGHT:

An integer value which specifies the weighting method to be used when performing the spectral sum. The supported values are given in Table  . Default is 2 (LTNORM).

WIDTHS:

Input float array which specifies the widths (MeV) of the output channels. Both edges and widths should be specified to override default gain computation.

Discussion SDR_SUM performs a live-time weighted sum of an array of SDRs into an output SDR. The summing assumes that the input array of SDRs have HDR, DAT, and ERR fields populated. SDR$SUM is called to perform the summing of data and correct update of header information.

OUT_SDR should be created before calling SDR_SUM.

NOTE:
Edges and widths returned in OUT_SDR are obtained via one of several alternatives. If edges and widths are supplied via the keywords EDGES and WIDTHS and have the correct dimensions, the supplied edges and widths are used. Otherwise, if edges and widths are found in the IN_SDR or in the corresponding SDB file, the average edges and widths are computed. If not, and the input data has 544 channels (no rebinning), edges and widths are computed by SDR_ESCALE using the SDB header RGAIN values in IN_SDR, otherwise no edges and widths are returned.
NOTE:
If input IN_SDR array contains data from multiple detectors, they all get summed into a single SDR_OUT with channel edges and widths averaged -- garbage in -- garbage out, unless the /BYDET keyword is used to sum by detector.