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CalDB Public Release Notes
Effective Date: (UTC) 2007-09-14T14:00:00
Public Release Date: 13 September 2007
Version: 3.4.1
Release Type: SDP + PUBLIC
 

I. INTRODUCTION

CalDB 3.4.1 contains the following additions:


II. SUMMARY OF CHANGES

A. ACIS T_GAIN updates (Epoch 30)

 Location: $CALDB/data/chandra/acis/bcf/t_gain/

Filenames: acisD2007-02-01t_gainN0005.fits   (EPOCHS 29 and 30)
acisD2007-05-01t_gainN0002.fits   (EPOCH 30 repeated)
acisD2007-02-01t_gainN0006.fits   (EPOCHS 29 and 30, BI chips CTI corrected)
acisD2007-05-01t_gain_biN0002.fits     (EPOCH 30 repeated, BI chips CTI corrected)

Piplines/Tools affected:

DS 7.6.11.1 ACIS L1 pipeline and CIAO 3.4 tool acis_process_events,
parameter "tgainfile", L1 Event File Keyword "TGAINFIL".

Analysis threads affected:

"Create a New Level=2 Event File"
http://asc.harvard.edu/ciao/threads/createL2/index.html#acis

"Apply the Time-Dependent ACIS Gain Correction"
http://asc.harvard.edu/ciao/threads/acistimegain/

CIAO Information Pages:
Please refer to the web page "How CalDB 3.4.1 Affects Your Analysis"
http://cxc.harvard.edu/ciao/releasenotes/ciao_3.4_release.html#HowCALDB3.4.1AffectsYourAnalysis

See also the ACIS Time-dependent Gain "why" page:
http://cxc.harvard.edu/ciao/why/acistgain.html

B. HRC-I GAPLOOKUP tables version N0003

Location: $CALDB/data/chandra/hrc/bcf/gaplookup/

Filename: hrciD1999-07-22gaplookupN0003.fits

Pipelines/Tools affected:
DS 7.6.11.1 HRC L1 pipeline and CIAO 3.4 tool hrc_process_events,
parameter degapfile, L1 event file keyword "GAP".

Analysis threads affected:
"HRC-I Degap Correction"
http://cxc.harvard.edu/ciao/threads/hrci_degap/

"Create a New Level=2 Event File: HRC Observations"
http://cxc.harvard.edu/ciao/threads/createL2/index.html#hrc
C. ACIS background file upgrades and additions

Location: $CALDB/data/chandra/acis/bcf/bkgrnd/
Filenames: (numerous; see table in Tech Details III.C.)

Note: BKGRND files are distributed in a separate tar ball from the main or upgrade CalDB tar balls, so that users
who maintain their own CalDB areas may decline to install them. There are currently 78 datasets included in the
Chandra ACIS blank field BKGRND file database.

Pipelines/Tools affected: reproject_events

Analysis threads affected:
"Using the ACIS 'Blank-Sky' Background Files"
http://cxc.harvard.edu/ciao/threads/acisbackground/

III.  TECHNICAL DETAILS

A. ACIS T_GAIN updates (Epoch 30)

Four files are included in the upgrade because 1) we are maintaining two different T_GAIN sets, one with BI chip T_GAIN corrections for the non-CTI corrected case, and one with
the appropriate corrections for the BI chips when the BI CTI correction IS applied, and 2) we provide a flat file to cover the final available epoch so that no long-term extrapolations are calculated in the absence of the next-in-line T_GAIN corrections, in this case the TBD Epoch 31 corrections (August-October 2007).
Table 1: New T_GAIN files and components, with the files being replaced. The  EPOCH1 and  EPOCH2 values given  are for the NEW files.
NEW FILENAME
(*.fits)
OLD FILENAME
(*.fits)
 EPOCH1
(UTC date in sec)
 DELTPHA1 INPUT
(*.fits)
 EPOCH2
(UTC date in sec)
DELTPHA2 INPUT
(*.fits)
 CVSD0001
acisD2007-02-01t_gainN0005
 acisD2007-02-01t_gainN0002
 290520065.184
 corrgain2007-02-01.v4
 298339265.184
 corrgain2007-05-01.v4
 2007-02-01
acisD2007-02-01t_gainN0006
 acisD2007-02-01t_gain_biN0002
 290520065.184
 corrgain2007-02-01.v4 (FI only),
corrgain2007-02-01.v5 (BI only)
 298339265.184
 corrgain2007-05-01.v4 (FI only),
corrgain2007-05-01.v5 (BI only)
 2007-02-01
acisD2007-05-01t_gainN0002
 none; new "flat" file
 298339265.184
 corrgain2007-05-01.v4
 306288065.184
 corrgain2007-05-01.v4 2007-05-01
acisD2007-05-01t_gain_biN0002
 none; new "flat" file
 298339265.184
 corrgain2007-05-01.v4 (FI only),
corrgain2007-05-01.v5 (BI only)		 306288065.184
 corrgain2007-05-01.v4 (FI only),
corrgain2007-05-01.v5 (BI only)		 2007-05-01

The EPOCH1 value is the midpoint between the CVSD value of the given file and the CVSD of the NEXT file in the series. The EPOCH2 value is the midpoint (numerical average) of the CVSD values from the next TWO files in the sequence. For the last two files in the table, EPOCH2 is the midpoint time between 2007-08-01T00:00:00 and 2007-11-01T00:00:00.

The files tagged as version N0002 above have the same data in DELTPHA2 as in DELTPHA1, and hence the file interpolates over two identical data values, and so the result is an identical value. Hence such a file is known as a "flat file", preventing two-point trends from being extrapolated too far into the future.

B. HRC-I GAPLOOKUP version N0003

We have discovered a need to improve the Off-Aimpoint gap map solution for HRC-I at certain locations. HRC Instrument Scientist Mike Juda has used a number of new observations of Capella from December 2005 to January 2006, and January 2007, to improve the degap solution table appropriately for the CRSU=12-13 region, while including a slightly more optimized solution for other detector positions. Hence we have determined that the new GAPLOOKUP table thus created is ready for release into the CalDB.

The memorandum including the derivation and degapping results, "HRC-I Degap Lookup from Capella Data - 2007," is posted at
http://hea-www.harvard.edu/~juda/memos/hrci_degap_lookup/capella/degap/2007/degap_lookup.html

Summary:
New  GAPLOOKUP tables for the HRC-I have been developed using January 2007 Capella calibration observations, combined with those taken in December 2005 and January 2006. The previous procedure, which used the aspect solution and known source positions to predict event locations on the detector, could not be maintained, because the 2007 observations predicted CHIP locations that deviated by 10-40 pixels from those actually measured, in particular for negative SIM_Z offset positions of HRC-I. This may be due to optical distortions of the FID light positions by the reflector-collimator assembly. An iterative scheme has been developed, which uses the measured source positions as part of the degap solution derivation process, to minimize the deviations. This has produced the new GAPLOOKUP table version N0003 for HRC-I.

C. ACIS "Blank Sky" Background File upgrades and additions

The -120C background files with CTI-corrected events have all been reprocessed, with the latest CTI-corrections, trap maps (ACIS-6), gain calibrations, and time-dependent gain corrections. Additionally, those cases with ACIS-S in the focal plane (signified by the "s" in the filename after the chip ID) with the CTI correction turned off (but with T_GAIN applied) have been reprocessed, as this covers a preponderance of the observations to which this mode is relevant. The result is that 48 new files have been added to the ACIS BKGRND file database in the CalDB in version 3.4.1, 12 of which are new, and 36 of which are upgrades of previously released datasets. In part because of our separating the files by CCD_ID, and in part because of the subdivisions due to the focal plane positioning of the arrays, the CTI correction status, and the various operating temperatures, our background file database now comprises 78 files.

Table 2 below delineates the upgrades, new files, and retained files individually by name. The files designated as UPGRADES may include such improvements and updated GAIN, T_GAIN, and CTI corrections, as well as updating the handling of bad pixels and detector coordinate calculations to our latest standards, i.e., the standards set by current pipeline processing at the CXC. This makes these datasets fully compatible with the Chandra Data Archive, including the most recent round of reprocessing ("Repro III").
Table 2: ACIS BKGRND "Blank Sky" dataset upgrades, new files, and retentions included in CalDB 3.4.1

OLD FILENAME

NEW FILENAME

RETAINED, UPGRADED, or NEW?

acis0iD1999-09-16bkgrndN0002.fits

N/A

File retained in CalDB

acis1iD1999-09-16bkgrndN0002.fits

N/A

File retained in CalDB

acis2iD1999-09-16bkgrndN0002.fits

N/A

File retained in CalDB

acis2sD1999-09-16bkgrndN0002.fits

N/A

File retained in CalDB

acis3iD1999-09-16bkgrndN0002.fits

N/A

File retained in CalDB

acis3sD1999-09-16bkgrndN0002.fits

N/A

File retained in CalDB

acis5sD1999-09-16bkgrndN0002.fits

N/A

File retained in CalDB

acis6iD1999-09-16bkgrndN0002.fits

N/A

File retained in CalDB

acis6sD1999-08-12bkgrndN0002.fits

N/A

File retained in CalDB

acis6sD1999-09-16bkgrndN0002.fits

N/A

File retained in CalDB

acis7iD1999-08-12bkgrndN0003.fits

N/A

File retained in CalDB

acis7iD1999-09-16bkgrndN0002.fits

N/A

File retained in CalDB

acis7sD1999-08-12bkgrndN0002.fits

N/A

File retained in CalDB

acis7sD1999-09-16bkgrndN0002.fits

N/A

File retained in CalDB

acis8sD1999-09-16bkgrndN0002.fits

N/A

File retained in CalDB

acis9sD1999-09-16bkgrndN0002.fits

N/A

File retained in CalDB

acis0iD2000-01-29bkgrndN0003.fits

N/A

File retained in CalDB

acis0iD2000-12-01bkgrndN0002.fits

N/A

File retained in CalDB

acis1iD2000-01-29bkgrndN0003.fits

N/A

File retained in CalDB

acis1iD2000-12-01bkgrndN0002.fits

N/A

File retained in CalDB

acis2iD2000-01-29bkgrndN0003.fits

N/A

File retained in CalDB

acis2iD2000-12-01bkgrndN0002.fits

N/A

File retained in CalDB

acis3iD2000-01-29bkgrndN0003.fits

N/A

File retained in CalDB

acis3iD2000-12-01bkgrndN0002.fits

N/A

File retained in CalDB

acis6iD2000-12-01bkgrndN0002.fits

N/A

File retained in CalDB

acis7iD2000-01-29bkgrndN0004.fits

N/A

File retained in CalDB

acis7iD2000-12-01bkgrndN0003.fits

N/A

File retained in CalDB

acis8iD2000-12-01bkgrndN0003.fits

N/A

File retained in CalDB

acis1sD2000-01-29bkgrndN0003.fits

acis1sD2000-01-29bkgrndN0005.fits

UPGRADE


acis1sD2000-12-01bkgrndN0001.fits

NEW FILE SPEC

acis2sD2000-01-29bkgrndN0003.fits

acis2sD2000-01-29bkgrndN0005.fits

UPGRADE

acis2sD2000-12-01bkgrndN0002.fits

acis2sD2000-12-01bkgrndN0005.fits

UPGRADE

acis3sD2000-01-29bkgrndN0003.fits

acis3sD2000-01-29bkgrndN0005.fits

UPGRADE

acis3sD2000-12-01bkgrndN0002.fits

acis3sD2000-12-01bkgrndN0005.fits

UPGRADE

acis5sD2000-01-29bkgrndN0004.fits

acis5sD2000-01-29bkgrndN0005.fits

UPGRADE

acis5sD2000-12-01bkgrndN0003.fits

acis5sD2000-12-01bkgrndN0005.fits

UPGRADE

acis6sD2000-01-29bkgrndN0003.fits

acis6sD2000-01-29bkgrndN0005.fits

UPGRADE

acis6sD2000-12-01bkgrndN0002.fits

acis6sD2000-12-01bkgrndN0005.fits

UPGRADE

acis7sD2000-01-29bkgrndN0004.fits

acis7sD2000-01-29bkgrndN0005.fits

UPGRADE

acis7sD2000-12-01bkgrndN0003.fits

acis7sD2000-12-01bkgrndN0005.fits

UPGRADE

acis8sD2000-01-29bkgrndN0004.fits

acis8sD2000-01-29bkgrndN0005.fits

UPGRADE

acis8sD2000-12-01bkgrndN0003.fits

acis8sD2000-12-01bkgrndN0005.fits

UPGRADE

acis0iD2000-01-29bkgrnd_ctiN0004.fits

acis0iD2000-01-29bkgrnd_ctiN0005.fits

UPGRADE

acis0iD2000-12-01bkgrnd_ctiN0003.fits

acis0iD2000-12-01bkgrnd_ctiN0004.fits

UPGRADE

acis1iD2000-01-29bkgrnd_ctiN0004.fits

acis1iD2000-01-29bkgrnd_ctiN0005.fits

UPGRADE

acis1iD2000-12-01bkgrnd_ctiN0003.fits

acis1iD2000-12-01bkgrnd_ctiN0004.fits

UPGRADE

acis2iD2000-01-29bkgrnd_ctiN0004.fits

acis2iD2000-01-29bkgrnd_ctiN0005.fits

UPGRADE

acis2iD2000-12-01bkgrnd_ctiN0003.fits

acis2iD2000-12-01bkgrnd_ctiN0004.fits

UPGRADE

acis3iD2000-01-29bkgrnd_ctiN0004.fits

acis3iD2000-01-29bkgrnd_ctiN0005.fits

UPGRADE

acis3iD2000-12-01bkgrnd_ctiN0003.fits

acis3iD2000-12-01bkgrnd_ctiN0004.fits

UPGRADE

acis6iD2000-01-29bkgrnd_ctiN0004.fits

acis6iD2000-01-29bkgrnd_ctiN0005.fits

UPGRADE

acis6iD2000-12-01bkgrnd_ctiN0003.fits

acis6iD2000-12-01bkgrnd_ctiN0004.fits

UPGRADE


acis7iD2000-01-29bkgrnd_ctiN0001.fits

NEW FILE SPEC


acis7iD2000-12-01bkgrnd_ctiN0001.fits

NEW FILE SPEC


acis8iD2000-12-01bkgrnd_ctiN0001.fits

NEW FILE SPEC

acis1sD2000-01-29bkgrnd_ctiN0004.fits

acis1sD2000-01-29bkgrnd_ctiN0005.fits

UPGRADE

acis1sD2000-12-01bkgrnd_ctiN0003.fits

acis1sD2000-12-01bkgrnd_ctiN0005.fits

UPGRADE

acis2sD2000-01-29bkgrnd_ctiN0004.fits

acis2sD2000-01-29bkgrnd_ctiN0005.fits

UPGRADE

acis2sD2000-12-01bkgrnd_ctiN0003.fits

acis2sD2000-12-01bkgrnd_ctiN0005.fits

UPGRADE

acis3sD2000-01-29bkgrnd_ctiN0004.fits

acis3sD2000-01-29bkgrnd_ctiN0005.fits

UPGRADE

acis3sD2000-12-01bkgrnd_ctiN0003.fits

acis3sD2000-12-01bkgrnd_ctiN0005.fits

UPGRADE

acis6sD2000-01-29bkgrnd_ctiN0004.fits

acis6sD2000-01-29bkgrnd_ctiN0005.fits

UPGRADE

acis6sD2000-12-01bkgrnd_ctiN0003.fits

acis6sD2000-12-01bkgrnd_ctiN0005.fits

UPGRADE


acis5sD2000-01-29bkgrnd_ctiN0001.fits

NEW FILE SPEC


acis5sD2000-12-01bkgrnd_ctiN0001.fits

NEW FILE SPEC


acis7sD2000-01-29bkgrnd_ctiN0001.fits

NEW FILE SPEC


acis7sD2000-12-01bkgrnd_ctiN0001.fits

NEW FILE SPEC


acis8sD2000-01-29bkgrnd_ctiN0001.fits

NEW FILE SPEC


acis8sD2000-12-01bkgrnd_ctiN0001.fits

NEW FILE SPEC

acis0D2000-12-01bgstow_ctiN0003.fits

acis0D2000-12-01bgstow_ctiN0004.fits

UPGRADE

acis1D2000-12-01bgstow_ctiN0003.fits

acis1D2000-12-01bgstow_ctiN0004.fits

UPGRADE

acis2D2000-12-01bgstow_ctiN0001.fits

acis2D2000-12-01bgstow_ctiN0002.fits

UPGRADE

acis3D2000-12-01bgstow_ctiN0003.fits

acis3D2000-12-01bgstow_ctiN0004.fits

UPGRADE

acis6D2000-12-01bgstow_ctiN0003.fits

acis6D2000-12-01bgstow_ctiN0004.fits

UPGRADE

acis5D2000-12-01bgstowN0003.fits

N/A

File retained in CalDB


acis5D2000-12-01bgstow_ctiN0001.fits

NEW FILE SPEC

acis7D2000-12-01bgstowN0003.fits

N/A

File retained in CalDB


acis7D2000-12-01bgstow_ctiN0001.fits

NEW FILE SPEC




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