Calibration Access and Data Handbook

Description

A new CCF structure has been defined to support the new CTI correction algorithm ($ALGOID = 2$) used by the CAL CtiCorrector.cc

In extension 'CTI_EXTENDED' there are three columns for the serial CTI (CTI_X columns) and three columns por the parallel CTI (CTI_Y columns) that describes the CTI degradation per CCD, node and mode (same correction for both nodes and all modes) :

• the constant term ( coefficients [0] in 3.3.9 equations )
• the linear degradation rate (coefficients [1] in 3.3.9 equations)
• the power law index (coefficients [2] in 3.3.9 equations)

In extension 'CTI_COLUMN' we can take account for step-like changes within the column offsets. Ignoring these steps would lead to an over- or understimation of the real CTI losses. The table contains offset values for all columns, in case no correction is needed, the offset value is zero with RAWY_START=0 and YLENGTH=600.

For each major period where the CTI trend displayed different degradation rates, there is one CCF per MOS and period.

Note that the extension 'CTI' is obsolete and not maintained anymore. This approximate set of CTI parameters was originally intended for QLA (and/or for SciSim ?).

The CCF contains three tables:

CTI :

This table is not used by the CAL.

Attributes:

None.

Columns:

CCD_ID:

CCD index number (1-7).

CTI_X:

single scalar fractional charge loss in serial direction.

CTI_Y:

single scalar fractional charge loss in parallel direction.

CTI_EXTENDED:

This table is accessd by CAL_mosCTIcorrection()

Attributes:

REF_DATE:

reference date in ISO format yyyy-mm-ddYhh:mm::ss

CTX_RATE:

serial CTI rate change coefficient for ALGOID=0 only, so not used anymore.

CTY_RATE:

parallel CTI rate change coefficient for ALGOID=0 only, so not used anymore.

Columns:

MODE_ID:

numeric ID of the mode.

CCD_ID:

CCD index number (1-7).

NODE_ID:

ID of the readout node [0, 1].

CTI_FRAME_TRANSFER:

(only in ALGOID=0 CCFs) the column is not used by the CAL

D_CTI_FRAME_TRANSFER:

(only in ALGOID=0 CCFs) absolute error of CTI_FRAME_TRANSFER values; column not used by the CAL.

CTI_X:

fractional charge loss parameter in serial direction; vector column with size 2/4/3 corresponding to ALGOID=0/1/2

D_SERIAL_CTI:

(only in ALGOID=0 CCFs) absolute error of CTI_X values; column not used by the CAL.

CTI_Y:

fractional charge loss parameter in parallel direction; vector column with size 2/4/3 corresponding to ALGOID=0/1/2

D_CTI_PARALLEL:

(only in ALGOID=0 CCFs) absolute error of CTI_Y values; column not used by the CAL.

CTI_COLUMN:

This table is accessed by CAL_mosCTIcorrection()

Attributes:

None.

Columns:

CCD_ID:

CCD number [1-7].

NODE_ID:

CCD readout direction (node identifier) [0,1].

RAWX:

CCD column number RAW-X [0-599].

RAWY_START:

RAW-Y start position of a column segment within a column [0-599].

YLENGTH:

Length of the column segment [1-600].

OFFSET:

The offset of the column segment in energy (ADU).