DATA Table

The DATA binary table extension contains raw accumulated total power integrations for each phase of each CCB input port that was used for a given scan.

The first (DMJD) column of the data array contains the MJD of the integration start.

The DATA column is a multidimensional column with dimensions (NPORTS,NPHASES). Each datum is recorded as a 32 bit two's complement integer; subsequent transformation to unsigned values is facilitated by recording a TZERO keyword with a value of $2^{31}$. The order of the PORT and PHASE sub-columns should correspond to the order of the rows in the PORT and CCBSTATE tables respectively. The number of phases NPHASES is determined by the number of active switches and is 1, 2, or 4. The number of ports NPORTS is equal to the number of ports selected in the manager as active for the given scan.

A second multi-dimensional OVRFLOW column, of the same dimensions as the DATA column, comprises LOGICAL data with "T" indicating integrations that overflowed and "F" indicating integrations that did not. The value at subcolumn M row N in the OVRFLOW column denotes the overflow status of the integration datum at subcolumn M row N of the DATA column.

One multi-dimensional LOGICAL column contains the four SLAVEOK flags. Two LOGICAL columns contain CAL A and CAL B ON flags indicating whether, for a given integration, a given call was on or not; the ``integration usable'' flag is a separate SHORT-INT column, indicating whether each integration is usable based on the cal diode rise and fall time flags applied by the CCB.

Comments

• Integration data are returned by the CCB as unsigned 32 bit integers. Conversion from signed 32 bit two's complements values, to unsigned 32 bit values, may require use of double precision on the data processing end.
• The ``integration usable columns'' is short int not logical in order to more closely line up the columns with machine byte boundaries, for better performance.
• The SLAVEOK flags can be associated with individual columns of data (ie input ports) using the information in the SLAVE column of the PORT table.
• The cabling-dependent mapping of the CCB's ``Cal A'' and ``Cal B'' to a physical Cal diode (nominally Left and Right, or perhaps, tags in the calibration FITS file database) is presently unspecified.