Re: C* 2315 r obs by Walter Nissen

Bart De Pontieu (BDP@MPEPL)
Tue, 07 May 1996 19:54:37 +0100 (CET)

Some comments on what Kurt and Jim wrote regarding reporting PPAS/DRA 
observations:

>>changing the DRA-format(start-time), I welcome your thoughts on this. 
>I think we should continue to use the start-time.  Bart already implemented
>two ways of using this start-time: 
>Using end-time would make things much more difficult...  all timings
>then should appear with a minus before them and this looks uncomfortable
>to me, just like going back in time... :)

I agree that it's easier to use the beginning time, rather than the ending
time. So, we keep using the start time for DRA obs and the end time for
the PPAS?

And then I screwed up when writing the following, but Jim corrected me:

>>So my final suggestion about what to report would be:
>>95- 32 B 96-04-18  1:38:45.2 WN  234.3 1.5  18 13.02  A'A', C* 2315 r  (??)
>                    ^^^^^^^^^
>                   This should be 1:42:39.5 to convert the DRA obs into
>                   a PPAS obs.  [Walter's original e-mail asked for suggestions
>                   on what to post to PPAS]

I had a nagging feeling that I had overlooked something after writing that
message. Jim found out what it was :-)

>I apologize for my confusion regarding the DRA vs. PPAS formats.  The two
>reporting formats are identical, so it is easy to confuse the two and fall
>into this trap.

The DRA and the PPAS formats are very different from one another. To clarify,
the above line is a typical PPAS-line. The PPAS-format is always one line.
The DRA format is not one line, but multiple lines. Here's a fictious
example based on a (shortened) observation of Walter:

-------------------------------------- 
   96    4  Year and month (2I5) 
   41.3735  -81.8637      256.  lat, long, hgt (3F10.0) 
   18    1   38 45.24  10  Start day,hr,mn,sec  nbr timings 
  0.00  0 
  5.66  1 
 13.06  2 
 38.59  3 
 51.22  4 
 58.27  5 
 65.49  6 
 77.42  7 
 90.04  8 
103.65  9 
1 23604U 95032  B 96102.21488710  .00000015  00000-0  00000-0 0   956 
2 23604  82.9028 149.1106 0025208 201.7756 158.2328 13.73606274 38585 
-------------------------------------

Note that the DRA-format is nowhere close to the PPAS-format.

However, there was no way for you to know what the DRA-format was, since it
has not been used since you subscribed to SeeSat. The DRA-project has been
dormant for the last year.

>So, I have to conclude that there needs to be a way of making the DRA and the
>PPAS formats distinguishable from one another.  There's probably a hundred ways
>of doing this.  Here's one possible solution for your consideration:
>95- 32 B 96-04-18S 1:38:45.2 WN  234.3 1.5  18 13.02  A'A', C* 2315 r (??)

See above, you're quoting a normal PPAS-obs, not a DRA obs. Every DRA obs
should get some kind of PPAS-line to 'compile' all individual timings into
one line.

>>True. I think Jim is talking about the 'variation of the synodic effect',
>>not about the 'synodic effect' per se. This is a common source of confusion
>>when discussing the synodic effect. Mike should be used to this confusion now,
>>given that he has discussed the topic of 'synodic effect' with me in dozens 
>>of mail messages :-)
>I seem to have a knack for stumbling into issues that have been previously
>discussed and considered.  

The fact that Mike and I have had a long-living e-mail conversation on this
during the last 2 years does not mean the topic should not be discussed 
anymore. Quite on the contrary. Our conversation was private, how were you
to know about it ? It has hardly ever been discussed on
SeeSat, so as such the current discussion is not a rehash. 

>Clumsy me :) Perhaps the synodic effect could be 
>incorporated into the FAQ?  It may not be truly a 'frequently asked 
>question,' but it may help prevent another new observer from reopening 
>this topic.

To be frank with you, the only reason why it is not decently explained in
the VSOHP Web pages (which were partly based  on the BWGS english language
brochure) is because at the time of writing the chapter about the synodic 
effect, we were still 'learning' about it.
It is perhaps time to write down the 'knowledge' we have 'rediscovered'
in a good clear text. The FAQ could be a possibility, I guess.

Kurt comments on what I wrote:

>>Something unusual happened in the middle of the obs, but since the flash
>>periods in the first part and the last part of the pass were 13.0 +- 0.13
>>and 12.8 +- 0.2, which is not incompatible, just one obs should be reported.
>>A remark could be added in the remarks column (or a separate remark, we do
>>accept those too now) about the weird stuff happening in the middle.
>Yes, that's possible, but I wouldn't encourage observers to generate more
>reports that they are already doing now (= DRA - and PPASreport).  
>A third 'separate remark' wouldn't normalle give additional information 
>than the DRA - report.
>Of course in some special cases one can add as a separate report, but
>I don't like to see the remark-file filled with DRA-reports...
>Maybe the best solution is to report 'DRA' in the remarks-column, then
>people wanting to know more can ask for the DRA-reports.
>What do you think of this suggestion?

I think it's a very good suggestion. I intend to get off my lazy butt and
start up a DRA observations database, with monthly updates or so. So far
we've amassed already quite a few observations. I'm
still wondering in what form I would make it available. I hope to have 
something ready in a month or so.

Cheers,
    Bart

-------------------------------------------------------------------------------
Bart De Pontieu --  Max-Planck-Institute for extraterrestrial Physics, Garching
bdp@mpepl.plasma.mpe-garching.mpg.de -- http://www.rzg.mpg.de/~bdp/eurosom.html
BWGS-coordinator -- Flash editor -- SeeSat-L administrator -- would-be-observer
           "Oh, I'm a sat-watcher, and I'm okay,"
        "I 'Quicksat' all night and I sleep all day!" -- Jim Varney
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