2.   PIA P32 TOOLS (main window)

 

Figure 2: Main window for P32 Tools with default settings.

 

This window is the switchboard of the P32Tools package. The top panel gives the characteristic parameters of the measurement. The 'SHOW' panel provides quick-look access to various maps and measurement details. The 'DRIFT processing' panel contains the global parameters for the drift fitting routines. Finally, the bottom panel deals with executing the drift fitting, inspecting and saving results as well as exporting the processed data back to PIA.

 

2.1    Measurement characteristics (Top Panel)

Characteristic parameters of the selected measurement are displayed:

 

2.2    SHOW      (Data/map visualization)

This panel combines the different options to quickly examine satellite or instrument specific data of the map and to visually inspect map results.

Pixel Map
Shows contour plots of the P32 maps created from the signals of each individual detector pixel. The units along the axis of the map are arc sec.
Grid
Shows the data sampling during the observation. The individual positions of pixel 1 during the whole observation are marked on a grid. The horizontal axis corresponds to the y-axis of the spacecraft. The vertical axis corresponds to the z-axis of the spacecraft. The units along the axis of the chart are arc sec. The observation starts in the upper right corner and continues to the left and downwards.
Header
Displays the fits header of the observation. The header mainly contains information on satellite parameters and on planning logistics. For a detailed description see the ISOPHOT Handbook.
Com. Status
Displays the compact status file (PSTA file) of the observation. This file contains a summary of the measurements in an observation. For a detailed description of the parameters contained in this file, see the ISOPHOT Handbook.
Map DISPLAY Options
Launches a new window which allows to select the map units, flat fielding and the treatment of the slew data. (See Section 3 .)
DISPLAY_MAP
Display the current map. The parameters selected in 'Map DISPLAY Options' will be used. The same interface as in PIA Astrophysical Work will appear.

 

2.3    DRIFT processing (Middle Panel)

This panel controls the influence of the uncertainties on the drift fitting. It determines how the data taken during slewing is handled and how many times various parts of the drift fitting are iterated. It also allows saving and restoring of the drift fitting parameters for the whole detector array.

 

2.3.1 Determine the errrors in the result by:

Within P32Tools the uncertainties are used to constrain the drift fit. Uncertainties can be taken either from the statistical uncertainties of the signals on each chopper plateau or from the dispersion of redundant sky samples obtained with the same detector pixel. Based on these two independent determinations, four different options are available.

Measurement errors
Adopts the statistical errors for the erd2map process as they are for the drift correction process, i.e. the most unrealistic error.
Responsivity scaling
Multiplies the statistical errors of the erd2map process with the same correction factors as the data itself.
Internal dispersion
(default option)

Independent photometry estimates are derived for each sky sample and the dispersion of the flux values is adopted as error.
Flux step dispersion
Independent photometry estimates are derived for each sky sample and the dispersion of the flux values is adopted as error taking into account the flux steps before each sky sampling. I.e. flux samples with a preceding big flux step will be weighted less. This suppresses possible ghosts of bright sources in the final map.

 

2.3.2 Options of Using Slew Data:

The P32Tools package provides three different ways of treating the data taken during the slewing of the satellite from one raster point to another:

Excluded
The slews are not considered at all for the drift fitting.
Coadded
Data of one slew are coadded into one data point per chopper plateau of that data. The data points are then merged with the other to provide an uninterrupted flux history.
Sequence (default option)
All slew data are used independently.

 

2.3.3 Number of Iterations:

During the drift fitting process, various steps are iterated. First, the iteration of the starting conditions, since the initial illumination level has to be determined by 'sophisticated' guessing. Second, major iterations, to establish the overall illumination history and the drift fitting of the actual data.

# of Iterations for Start
Number of iterations to determine the starting conditions for the drift fitting.
Recommended for C100 : 1, for C200 : 2.
# of Major Iterations
Number of Iterations for drift fitting algorithm.
Recommended for C100 : 1, for C200 : 2.

 

2.3.4 Drift Fitting Parameters

For each pixel there is a set of 12 parameters that controls the fit of the drift behaviour. The whole parameter set for all detector pixels is handled by the associated line of buttons.

SAVE_TO_FILE
Saves the drift fitting parameter set to a file with the filename suggested in the popping-up file selection interface, which can be changed.
LOAD_FROM_FILE
Loads the drift fitting parameter set from a file with the filename specified in the popping-up file selection interface.
RESET_TO_DEFAULT
Resets the drift fitting parameters to the default values.

 

2.4 Drift    processing (lower panel)

CALCULATE_ON_ALL_
  PIXELS

Calculates the drift model for all individual pixels. This can take a very long time for a big map! This is generally the first step before working on individual pixels.
INSPECT_SINGLE_
  PIXELS

Opens a new window to access and improve the fitting parameters of the single pixels and to display, deglitch and analyze the data per pixel in detail, see Section 4 (Inspect Single Pixel).
SAVE / RESTORE
Saves a dataset to a specified filename or restores a selected dataset from disk. The saving does not include the drift fitting parameters for this solution! When restoring a dataset, it must coincide with the currently processed measurement to achieve a correct initialization of the buffers.
EXPORT_RESULTS_TO_
  SCP_LEVEL

Exports the drift corrected data to the SCP buffer of PIA for further data processing therein, i.e. calibration, astrophysical work, etc.
DISPLAY_MAP
Displays the map applying the current drift model. The parameters selected in Section 3 (Map DISPLAY Options) will be used.

 

2.5 Exiting ...       (Bottom Line)

Close      
Closes P32Tools, discarding all internal buffers of P32Tools.
CAUTION: Make sure that you have saved your (intermediate) results since they will be lost otherwise.
Help
Displays the help file for this window.

 


Other P32Tools helppages:
  1. Data Initialization Options
  2. Main Window
  3. Map Display Options
  1. Inspect Single Pixel
  2. Deglitcher

PHT32 Tools Help text      written by S. B. Peschke          July 2001