OGIP Calibration Memo CAL/GEN/92-003
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Release | Sections Changed | Brief Notes |
Date | ||
1992 Jun 06 | First Draft | |
1993 Jan 25 | All | Special issue for XTE GOF |
Apr 25 | Coordinate frames | Reviewed & updated |
1993 Oct 04 | All | Detailed Formats split off |
1994 Jan 05 | The CBDnxxxx String | New syntax introduced |
Jan 06 | Coordinate frames | LINX,LINY changed to DETX,DETY |
1994 Aug 09 | Section 4.1 | Added iCTYPnnn convention |
1995 Jan 27 | All | Made compatible with LaTeX2HTML software |
1995 Jul 11 | 11 | Added XMA_DCOS Coordinate system |
4.2 & 4.3 | Revised syntax | |
2004 Apr 01 | All | made compatible with tth |
2007 Mar 21 | title | changed title, minor typos fixed |
Keyword | Description | see |
Name | Section | |
Mandatory keywords always required | ||
CCLSxxxx | HEASARC-class of calibration file | 2.1 |
CCNMxxxx | extension codename | 2.1 |
CDESxxxx | descriptive string | 2.1 |
CDTPxxxx | datatype code | 5 & 2.1 |
CVSDxxxx | validity start date | 2.1 |
CVSTxxxx | validity start time | 2.1 |
INSTRUME | instrument name | 2.1 |
TELESCOP | satellite/mission name | 2.1 |
Keywords mandatory required under certain circumstances | ||
iCTYPnnn | The 'axis-labels' of n-d array | 4.2 |
CBDnxxxx | array describing parameter limitations of the dataset | 2.1 & 2.2 |
CREFnnn | The axis-to-column cross-referencing of n-d array | 4.3 |
CSYSNAME | spatial coordinate system in use | 11 |
CTASKLAN | language in which a standalone task was written | 5.1 |
CTASKLOC | disk location of executable of a standalone task | 5.1 |
CTASKNAM | name of standalone task | 5.1 |
DETNAM | detector name (if value of INSTRUME insufficient) | 2.1 |
FILTER | filter in use | 2.1 |
TDIMnnn | Number of elements & Ordering of n-d array | 4.1 |
[...] columns within a BINTABLE will have an associated character keyword TDIMnnn = '(i,j,k,...)' where i,j,k,... are the dimensions of the array, [and nnn is the number (nnn = 1, 2, 3, ..., 10, 11, ... 100, 101... etc) of the column in which the array is stored]. The data is ordered such that the array index of the first dimension given (i) is the most rapidly varying and that of the last dimension given in the least rapidly varying. The size implied by the TDIMnnn keyword will equal the element count specified in the TFORMnnn keyword. The adherence to this convention will be indicated by the presence of a TDIMnnn keyword in the form described above.Thus, if the example calibration dataset D referred to in the previous section had i=1024, j=20, k=30 & l=2 was stored in the 5th column with parameter i changing fastest, k the next fastest, j the next fastest, and l the slowest, then TDIM5 = '(1024,30,20,2)'. Within the HEASARC caldb, the TDIMnnn keyword is mandatory for all n-dimensional datasets stored within a column of a single row BINTABLE. The ordering of the parameters within the multidimensional calibration datasets described below has been chosen to facilitate access, and specifically to minimize access time. The ordering has therefore been determined on a calibration datatype-by-datatype basis, and is described in more detail for each individual datatype below. It is strongly recommended that a summary of what the ordering means physically for all n-dimensional arrays are also given via a liberal use of COMMENT keywords.
iCTYPnnn | Description |
String | Space along which axis is in ... |
ENERGY | Energy |
CHANNEL | (detector) Channel |
COORD-X | (spatial) Coordinate (dimension X, where X = 1, 2 etc |
CSYSNAME | Coordinate | Description |
value | Frame | |
spatial coordinate frames used for calibration datasets | ||
RAW_DET | Raw detector | as determined by on-board detector electronics |
(uncorrected in any way) | ||
LIN_DET | Linearized detector | all positional distortions due to detector removed |
PHY_DET | Physical Detector etc | in units of length on the detector/window/filter surface |
XMA_POL | Optical Axis | as defined by optical axis of mirror/collimator |
and orthogonal reference vector | ||
XMA_CART | Optical Axis | as above, but in using cartesian system |
XMA_DCOS | Optical Axis | as above, but in using direction cosines |