ISOCAM Interactive Analysis User's Manual Version 5.0 - ISO - ESA

142 CHAPTER 14. IMAGE ANALYSIS AND DISPLAY
14.4.10 An example
Simply starting ximage as,
CIA> ximage, raster
gives the following output:
>> click on data mode multiple choices button, choose overplot mode
>> click on the sky-view button
>> click on overplot mode multiple choices button, choose data mode
>> click on the raster button
>> move the mouse, click the left button to select a pixel
This tool can be used for example to test if one bright point in an image of a raster PDS is
real or an artifact due to memory effects (ghost) or to glitches.
Figure 14.12 shows a point of the mosaic (46,19) which is a ghost: one of the sky pointing has
seen a bright source before and the downward transient correction is not perfect. Figure 14.13
shows a point of the mosaic which is also an artifact: one of the sky pointing contains the tail
of long-time glitch (fader).
14.4.11 xv raster
xv raster, the pre-curser of ximage, is another cube analysis tool. What makes this tool
different from the rest is that it is shows you the pixel histories in the context of the raster
MOSAIC. This gives you a better idea how each pixel of the PDS cube affects the outcome of
the raster MOSAIC.
It can be invoked simply as:
CIA> xv_raster, raster_pds, output
Note from above that you need to supply the whole PDS to xv raster. Thevariableoutput
will return an array of pixel history data most recently viewed.
Take a look at Figure 14.14. Note the following points:
• The image displayed is the raster MOSAIC of the input PDS (in our example call above
this is raster pds). A cross-hair is positioned on the pixel of maximum intensity. The crosshair
can be moved by clicking on the image or by clicking on the buttons left, right, up,
down, center. Clicking on max will return it to the pixel of maximum intensity. Clicking
on Raster FOV will place a grid, representing the FOV of each EXPOSURE, over the
raster MOSAIC (as display in Figure 14.14).
• A plot of the history of the pixel under cross-hairs should also appear (this is not shown in
Figure 14.14.) Since you are viewing a raster observation, each raster MOSAIC pixel can
be made up of several EXPOSURE pixels, one per each SCD or STATE of the observation.
For this reason a history of each EXPOSURE pixel is shown in the plot window. Clicking
on multi or single will switch to individual plots or to an overplot of EXPOSURE pixel
histories respectively.
• Clicking the button mask will mark each masked pixel in the plot. Clicking on SCD limits
will place markers on the plots at the SCD boundaries.
• A postscript file of the plot, xv raster.ps, can be create by clicking on print.
• The button color will invoke IDL’s XLOADCT.