Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.naic.edu/~tghosh/a1863/calnotes Дата изменения: Wed Apr 20 16:58:54 2005 Дата индексирования: Sun Apr 10 02:29:21 2016 Кодировка: Поисковые слова: m 103

Hello again,

I hope this HTML formatted email is readable to everyone.

Here is another interesting aspect of the A1863 data. It is difficult
to see the pattern in the raw data, but when we calculate the simple
value for cal (literally calon-caloff for each of XX, XY, YX, YY) a
pattern of discretely changing cal at regular intervals is present. I
can only find it on day 53088 in wapp3 and one event in wapp4.

The attached file calxx.png is a view of the calculated cal for XX,
channel vs time, 53088 wapp3. calxx_slice.png is a slice through it to
clearly show the discontinuous values for cal. As you can see, the
value of cal appears to drop and become negative in steps through the
observation, and then steps back up in very regular time intervals for
all channels.

The table below tabulates the discrete changes in cal: the approx AST
time when the step takes place, and the new approx value that was
changed to. The delta columns show the difference between the entries
in the current row and the previous row:

*AST* *Cal
* *delta AST* *delta Cal
*
67856 0.05

68302 0.02 446 -0.03
68749 -0.01 447 -0.03
69197 -0.04 448 -0.03
69643 -0.05 446 -0.01
70090 -0.02 447 0.02
70538 0.01 448 0.03
70985 0.04 447 0.03
71954 0.04 969 0.01


The time intervals are very evenly spaced at about 7min27sec with fairly
consistent steps. There may have been another step between the last
two, but at an amplitude I cannot discern.

In Wapp4 there appears to be a step near the end of the observation at
AST 71971, but no others.

This data gets more and more interesting every time I look at it. I
can't wait to get to the ALFA data!

-jsd