Analysis of Un-De-Dithered Focus Plates
I've performed a simple analysis of the width of the trail in
the un-de-dithered HRC-I focus plate images. The analysis is
Spot diagrams and the statistics are plotted below. The center
of the time slices is plotted on the spot diagram.
- the exposures were divided into one second time slices, and
the image center of each slice determined using a
sigma-clipping algorithm, with a 1 sigma clip radius.
- the distance from each event to the center for its time
slice was determined
- distances which were greater than 20 pixels from the
derived center were tossed, to get rid of background events.
- the distances were then grouped into 15 second
slices. slices with less than 20 events were tossed.
the mean, RMS, and 80% half width of the remaining
slices was determined.
Last modified: Fri Sep 3 09:57:40 EDT 1999