WATTANA -------
FUNCTION Program to Analyze attitude data, in order to produce nominal pointing records reflecting the stability of the pointing or to concatenate attitudes of different observations.
USAGE wattana atifile(s) pntfile [options]
DESCRIPTION Analyzes the given attitude and by using some criteria (maximum arc-angle tolerance and maximum north-angle tolerance) to order to determine clusters of pointings of one or a grouipt of observations. Of each cluster record is produced containing its nominal (weighted average) pointing, its identification number (unique within all input files) and the number of members allocated to it. The pointing file will contain a record for each Nominal Pointing. The analysis can be done over several attitude files of different cameras. Attitude during a slew period is normally not to be taken into account as many pointings can be expected. It is an option to force analyzing also that part.
PARAMETERS
atifile [string] The (comma separated) name(s) of the input attitude FITS file(s) If more than one input file these files need not be in chronological (time sorted) order. However, the order of the input files must be equal and in the same order as the outputfiles. Of these attitude files must have filled their observation mode columns.
ptofile [string] The name of the resulting FITS file containing the Nominal Pointing of each grouped actual pointings.
(outfile=STDOUT) [string] Device or file to listing output.
(slewmode=no) [boolean] Force slewmode te be analyzed
(calfile1="-") [file name] The name of the input FITS file that contains among others the misalignment angles to calculate the instrument pointing.
(calfile2="-") [file name] Same as for calfile1, only used for SAX WFC-2.
(append=no) [boolean] It yes, use is made of an previous pointing file. All found pointings will be attempted to be placed in the existing pointing clusters and if unsuccesful a new nominal cluster pointing will be appended.
(ptifile="-") [string] The name of the input FITS file containing the Nominal Pointing of each grouped actual pointings. This option is only useful if pointings must be appended.
(parctol=0.25) [real] Maximum distance in degrees between the nominal pointing and that of the cluster members in pointing mode.
(prottol=0.05) [real] Maximum rotation in degrees difference between the nominal north-angle and those of its cluster members in pointing mode.
(sarctol=0.25) [real] Maximum distance in degrees between the nominal slewing and that of the cluster members in pointing mode.
(srottol=0.05) [real] Maximum rotation in degrees difference between the nominal north-angle and those of its cluseter members in slewing mode.
(calfile1="-") [file name] The name of the input FITS file from which are fetched the misalignment angles to calculate the instrument pointing.
(calfile2="-") [file name] Same as for calfile1, only used for SAX WFC-2.
(outfile=STDOUT) [string] Name of file for output listing. The volume of which is controlled by the verbosity level.
(verbsty=0) [integer] The verbosity level will control the output volume
(title=" ") [string] User caption to be tagged to each output FITS file header
(cluster=0) [integer] The Camera number (1 or 2) for which the clustering of the pointing must be analyzed in case raw the attitude data is used that has not been split per camera. (only for TEST purposes)
(pforce=no) [boolean] Force pointing mode for unknown modes (only for TEST purposes)
EXAMPLES
1. Analyze one attitude file and produce one pointing file
--> wattana FOTw1att1 FOTw1pnt1
2. Analyze two attitude files and produce new pointing file from existing one
--> wattana aFOTw1att1,bFOTw2att1 NEW_pnt append=yes ptifile=OLD_pnt
METHOD
- A simplified version of the method used with COMIS (by G.K.Skinner, B'ham) The full algorithm is not very stable and causes problems in some cases. Each attitude is assigned to the nearest Nominal Pointing. If an attitude falls outside the tolerated circle (arctol) around that Nominal Pointing or North Angle (a new NP will be initiated. - The actual assignment to a NP of events (photons) to a Nominal Pointing and a possible consequent position shift will be performed by program wshift.
REMARKS
- The program uses the parameter passing of the FTOOLS convention.
- Slew can be handled but will probably yield too many clusters to be of practical use. So in standard processing data in slew mode is skipped. (slewmode = no) In case it is enabled different tolerences can be specified for pointing and slew mode.
- There are two modes of operation a. In case of standard processing the attitude file is processed for the complete Observing Period per camera. This will result in two pointing files. b. In case of pointing clustering across several Observations of different Observing Periods (=FOTS) all related attitude files will be analyzed to produce one single nominal pointing file. That may involve the use of different cameras. In case the analysis is not done in one run by using the mulitple input file construct, the 'append=yes' mode for analyzing subsequent attitude files is required.
SEE ALSO watproc, wgtiflt, wshift