XMM-Newton Science Analysis System


attfilter (attfilter-1.4) [xmmsas_20230412_1735-21.0.0]

Parameters

This section documents the parameters recognized by this task (if any).

Parameter

Mand

Type

Default

Constraints

instexpid

yes

string

R1U571

six-characters long

A six-character string which must uniquely identify one exposure in the current ODF pointed at by the environment variable SAS_ODF. The first two characters designate an instrument (M1, M2, PN, R1, R2, OM), the third character must be S or U for the schedule status of the exposure and the last three characters are the zero-padded exposure number within the ODF.
 

attset

no

data set

atthk.dat

must exist

The name of the observation-wide attitude time series data set created by atthkgen.
 

timecol

no

string

TIME

name of existing D-type column in attset

The name of the column in the attitude data set containing the time tags – passed to tabgtigen in parameter timecolumn.
 

racol

no

string

AHFRA

name of existing D-type column in attset

The name of the column in the attitude data set containing the Right Ascension values of the star tracker viewing direction.
 

deccol

no

string

AHFDEC

name of existing D-type column in attset

The name of the column in the attitude data set containing the Declination values of the star tracker viewing direction.
 

apacol

no

string

AHFPA

name of existing D-type column in attset

The name of the column in the attitude data set containing the astronomical position angle values.
 

gtitable

no

table

attgti.ds:STDGTI

valid table identifier

The name of the resulting output GTI table - can be the name of an already existing table (which will get overwritten) or the name of a new one in an existing or new data set.
 

onlylastatt

no

boolean

false

none

If true only the last attitude points (100) are taken for calculating (median) the reference attitude for filtering.
 

filtertype

no

filter type selector

cone

cone$\vert$pyramid$\vert$user

A selection switch which determines the type of selection expression that the attitude time series is filtered with. cone and pyramid select the fixed cone- and pyramid filters (see above) respectively. The value user allows the specification of the expression directly via the parameter expression.
 

expression

no

attitude data filtering expression

selectlib-compliant expression

The expression that is to be used to perform the attitude data filtering in case filtertype=user. Before the expression is passed to selectlib the following substitutions are carried out:

substring	replaced by
%RA%	value of parameter racol
%DEC%	value of parameter deccol
%APA%	value of parameter apacol
%RA_MED%	computed median of Right Ascension of star tracker viewing direction
%DEC_MED%	computed median of Declination of star tracker viewing direction
%APA_MED%	computed median of spacecraft position angle
%TOL_n%	$n$th ($n>=1$) element in list of angles given by parameter tolangles

For example, the fixed cone-type filtering expression reads:
skyvector(%RA%*#RAD, %DEC%*#RAD) in cone(skyvector(%RA_MED%, %DEC_MED%), %TOL_1%)
 

tolangles

no

list of tolerance angles

#ARCMIN

selectlib-compliant numerical expressions

A list of selectlib-compliant expressions which must evaluate to a list of angle values in radians. Those values shall replace the symbolic constants %TOL_1%, %TOL_2%, $\ldots$, in the expression given in expression before this is passed to selectlib for performing the actual data filtering. For the fixed cone- and pyramid filter only the first and first two values shall be used respectively.
 

mingtisize

no

minimum size [s] of each GTI

10

$>0$

Any found good time interval shorter than this limit shall not be considered, i.e., not be written to the resulting output GTI table gtiset.
 

maxfracshort

no

maximum allowed fraction of GTIs shorter than mingtisize

0.1

$0<=$maxfracshort$<1$

The ratio of the sum of all too short GTIs (according to the minimum length given by mingtisize) and the total exposure time must not exceed this number. If it does a warning is issued and the user is prompted to review the specified tolerance limits (see tolangles).
 

Parameter

Mand

Type

Default

Constraints