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XMM-Newton Science Analysis System Page: 1
calview
July 2, 2008
Abstract
An interactive viewer of the XMM calibration database.
1 Instruments/Modes
Instrument Mode
all all
2 Use
pipeline processing no
interactive analysis yes
3 Description
The XMM calibration database is comprised of 100 calibration datasets (the current calibration le,
or CCF [1]), and a number of calibration algorithms and access functions (the calibration access layer, or
cal). Many of the datasets in the CCF contain parameters that are meaningful only in conjunction with
the calibration algorithms provided in the calibration access layer.
The fundamental philosophy of the XMM calibration database is that the only manner to access the
calibration data, either in raw form (the contents of the datasets themselves) or in the interpreted form
(the output of the algorithms) is through the functional interface provided by the calibration access layer.
While this approach has numerous advantages from the point of view of the task development process,
it also means that the eect of a given calibration quantity can only be visualized by writing a small
program to set the CAL state, and then call one of the calibration functions with the appropriate input
parameters.
The purpose of calview is to reduce the user's programming eort in this sense to nil. To achieve this,
and at the same time not require updating whenever a new calibration function is added to the cal,
calview interacts with the cal through the interfaces provided by the calibration state server, and the
calibration view server. The former is described in detail in cal. Here the two servers are described
brie y insofar as they are used by calview.
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XMM-Newton Science Analysis System Page: 2
The calibration state server allows one to set any of the calibration state parameters. These are: instru-
ment, ccd, node, lter and mode identiers, ccd and camera temperatures, on-chip binning factor, date,
accuracy level, and randomization. The top part of the calview widget pane (gure 1) can be used to
edit the calibration state. When a variable does not apply the corresponding widget is grayed out.
The behavior of the cal is also aected by the CCF in use. Through the pull down menu labelled \CCF"
(gure 1) one can direct the cal to use a particular set of calibration datasets. It is possible to point the
cal to a CCF directory, to a CCF index le (see cifbuild for information on how to generate one), or
add individual CCF components to an existing list. It is also possible to list all of the CCF constituents
in use, whether they were provided via the CIF or inserted at run time.
calview is also aected by the environment variables and command line options available to all SAS
tasks that make use of the cal. Refer to the cal documentation for details.
The calibration view server aects calview in two areas.
It allows the user to edit a number of state variables that aect the display of the calibration output.
The following variables can be set: energy, position in the eld of view, spectral order. These variables
function as input data to the calibration algorithms. For instance, for a given instrument and CCD the
user can select the energy for which the CCD redistribution should be calculated.
Through the calibration view server, calview inquires which \viewables" are available given the current
calibration state. The list of available viewables is available in the pull down menu labelled \View"
(gure 2). calview has no a priori knowledge of what calibration data can be viewed. Viewables can
have sub-viewables. These are specialized views of a given calibration quantity.
After a viewable is displayed, the list of CCF constituents accessed is displayed.
4 Parameters
This section documents the parameters recognized by this task (if any).
Parameter Mand Type Default Constraints
none needed by this task
5 Errors
This section documents warnings and errors generated by this task (if any). Note that warnings and
errors can also be generated in the SAS infrastructure libraries, in which case they would not be docu-
mented here. Refer to the index of all errors and warnings available in the HTML version of the SAS
documentation.
none issued by this task
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Figure 1: The calview user interface.
Figure 2: An example of the \View" pull down menu. Viewables with sub-viewables can be further
expanded.
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XMM-Newton Science Analysis System Page: 4
6 Input Files
1. The main input dataset, set through SAS CCF, is a Calibration Index File. See cifbuild for
more information on how to create such a le.
2. Any CCF dataset complying with the interface dened by the cal.
7 Output Files
None. The user can save the displayed data to disk for analysis with a custom tool.
8 Algorithm
There is no algorithm proper. calview interrogates the calibration state server and the calibration view
server, and it displays the results in a number of widgets and pull down menus. Each time the value of
one of the state variables is changed, calview loops through all the widgets and menus to bring them in
line with the new state.
9 Comments
Not all the calibration viewer variables are meaningful to all viewables. At the moment
there is no way to know which variable aects which viewable, although it is fairly easy to
guess.
The calibration view server may fail to initialize if the Calibration Index File does not
contain all of the required datasets. At the moment the only way of knowing if all the
required datasets are available is to try and run calview.
The Calibration Index File and the CCF that the users receive with their data is complete
and can be used with calview.
References
[1] ESA. Interface control document for the XMM current calibration le. Technical Report XMM-GEN-
ICD-0005, ESA/SSD, Dec 2001. Issue 4.0.
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