4.   PIA P32 TOOLS - Inspect Single Pixel

 

Figure 1: Window for Inspect Single Pixel with default settings.

 

The window gives access to the drift fitting parameters of an individual pixel. It furthermore provides a platform for deglitching the data, for displaying the data and for optimizing the drift fit.

 

4.1    Pixel Selection and Display Options (Top Panel)

This panel is dedicated to the pixel selection and selection of display options.

 

4.1.1 Pixel

The desired pixel can be selected using a slide bar, starting with pixel 1 (4 pixels for C200 and 9 pixels for C100).

 

4.1.2 Deglitch

This button invokes the deglitching interface and is described in Section 5.

 

4.1.3 Display Rebin:

These radio buttons offer a choice of rebinning possibilities for displaying the data. The P32 Tools software operates on the pairwise differences of subsequent readouts, these differences divided by the time between the readouts (=signals) are shown by default. Depending on the size of the map one can reduce the number of data points displayed by taking the average signals over a period in time.

No rebin
All data points will be displayed.
per ramp
The average per integration ramp will be displayed.
per chopper
The average per chopper plateau will be displayed.

 

4.1.4 Display Signals

This button invokes the signal display window. Note that flagged data points are displayed only in the case of "no rebinning".

 

4.2    Drift Fitting Parameters

This panel controls the drift fitting parameters for each pixel and determines which drift fitting approach is taken.

 

4.2.1 Parameter field

For each pixel the drift fit is controlled by 4 parameters, Each of them is of the form A+B (illumination)^C. This leads to a total of 12 parameters per pixel. The drift solution is composed of two components, a slow ( ) and a fast ( ) one. The slow component is more tied to the long term detector behaviour, while the fast one can be regarded as short term behaviour typical to a particular measurement. In general is considered to be the jump factor while corresponds to the time constant of the relaxation time. For more details see Tuffs et al. (in Proceedings of the P32 workshops).

By default, the parameter fields have been filled with the most probable parameters as derived from calibration observations. The values can be modified directly by typing into the fields. A button which enables each parameter to become free during the iterations is provided next to each parameter field. As indicated in the panel, not more than 6 parameters can be set free to prevent the solution from diverging.

 

4.2.2 Reset flags and parameters

RESET
Pressing this button fixes all parameters to their values in the main P32 window.
RESET_TO_DEFAULTS
Pressing this button resets all parameters to their default values. The values that they contained before are lost.

 

4.2.3 Raster point selection

This section helps to select only parts, i.e. continuous sequences of raster points, of the map for drift fitting. Ranges as small as one raster point are allowed.
As default setting, the total number of raster points of the map is displayed. Thereafter, a selection of a sub-map can be made. The first pointing of the map is referred to as raster point 1. Within the 'DISPLAY map' interface, the starting point of the map is always laying in the upper right corner. The next raster pointings continue to the left and downwards.

 

4.2.4 Self calibration

Self calibration can only be applied if one or more of the drift fit parameters are freed. For a detailed description of the idea and its application, more details can be found in the proceedings of the PHT32 workshops.

Full Range
Calculate the illumination history and the drift fit continuously for the full range of raster points specified.
Composite
Can only be applied for one raster point (at the time), i.e. the start and end point of the selected range are identical. All chopper sweeps of this one raster point are merged into one composite chopper sweep. This reduces the noise and improves the processing speed, however, the illumination history of the detector is not taken into account.
Re-Calculate Parameters
This button executes either the full range or the composite method to self calibration, with one or more drift fit parameters set free. In case no free parameters and full range have been selected, the result is the same as for the general drift fitting.

 

4.3   Exiting ...     (Bottom line)

ACCEPT
Closes the window accepting the options checked and the current set of drift fit parameters. The current drift fit parameters are adopted overwriting the previous/initial ones irreversibly.
CLOSE
closes the window discarding all changes made to the window configuration upon initial entry. The current drift fit solution is lost if it was not the initial one.
HELP
Displaying 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