Re: tumbling rocket and satellite

From: Alain Figer via Seesat-l <seesat-l_at_satobs.org>
Date: Mon, 22 Apr 2019 13:37:42 +0200
Very interesting. Superb !

> it could be a string describing the pattern, or it could be a data series
in some format to store the whole light curve.

I would strongly plead for setting a link to access the whole light curve
and/or photographic images.
Many light curves are quite complex and deserve a careful examination.
Focussing only on the period values is too restrictive, I mean. Especially
after half a century of such a work of period assessing by amateurs. It's
time, I believe,  to go beyond mere period variations and try and link
photometric variations to the precise geometry of the satellite.

Regards
Alain Figer

Le lun. 22 avr. 2019 à 13:15, <Daniel.Hampf_at_dlr.de> a écrit :

> Folks,
> I've been following this discussion with great interest. We are recording
> a lot of light curves and derive rotation periods from them. I've set up a
> little web database specifically for this task, but it is currently only
> accessible from our intranet. But I could change that easily. This web
> database already contains measurements from different sources, but would
> need to expand a lot. It would also be great to couple it with the old PPAS
> records, to get long term evolutions.
> I am happy to make this website public and the data completely open and
> unrestricted (creative commons or something). If I'd get some programming
> help it'd be faster, but I can also do it myself.
> On the other hand, I am also happy to supply our data anywhere if there is
> a good database.
> One thing I wonder is the best data format: It could be only a float
> (rotation or flash period), it could be a string describing the pattern, or
> it could be a data series in some format to store the whole light curve.
> Maybe one should offer all options.
> Best regards
> Daniel
>
>
> ________________________________________
> From: Seesat-l [seesat-l-bounces+daniel.hampf=dlr.de_at_satobs.org] on
> behalf of Alain Figer via Seesat-l [seesat-l_at_satobs.org]
> Sent: Monday, April 22, 2019 11:54 AM
> To: Brad Young; Tristan Cools; alberto rango; Leo Barhorst; Kevin Fetter
> Cc: Seesat-L
> Subject: Re: tumbling rocket and satellite
>
> Many thanks, Brad, for your enthusiastic response.
>
> At the moment I identified in the SeeSat-L a handful of observers showing a
> significant interest in optical behaviour of satellites.
> Our number is rather limited it seems. Moreover each of us have their own
> objectives and methods - all different from those of each other -  and
> that's ok.
> However that probably sets limits to our present ambition.
>
> A problem we are facing is adding our competences and contributions without
> substracting whatever to each other's work.
>
> It's not necessary, IMO, that we change anything to our methods now.
> As a first step we  could simply locate all the stuff we are producing
> about optical behaviour of satellites in a single data center.
> Anyone could choose to use either the PPAS/PFAS format or not.
>
> Alberto, Brad and Kevin seem to keep for theirself to the PPAS/PFAS format.
> Whereas Leo is using his well-known own system such as :
>
> "28538 05 004B 4172 G 20180224210336756 F, P ~ 22 sec.
> 23862 96 029D 4172 G 20180225032313460 F, P ~ 13 sec.
> 24795 97 020D 4172 G 20180225034230488 F, P ~8 sec. with Fff
> 21798 91 082A 4172 G 20180225054552448 F, with FA "
>
> and could keep to it.
> As for me I prefer posting a whole paper about each observation, as I have
> been currently doing at Flickr for 7 years.
>
> If all our contributions were also present in the same data center, it
> would be much easier to perform synthesis work, at will.
> In such a mindset I issued Leo Barhorst 2014-2018 observations in the
> Flickr's data center here :
>
>
> https://www.flickr.com/groups/satellites_artificiels/discuss/72157689682699925/
>
>
> For exemple this data center is open to receive contributions by anybody,
> everybody being allowed to issue and update their own contributions there.
> Synthesis work could be added there by anyone willing to do it..
> Obviously another data center could be proposed for such a collaborating
> platform. I am obviously ready to accept any other suggestion.
>
> Regards
> Alain Figer
>
> Le lun. 22 avr. 2019 à 09:15, Brad Young <allenb_young_at_yahoo.com> a écrit
> :
>
> > I would be very interested too, as I always enjoy viewing satellite
> > optical behavior, and have missed the activity of PPAS and the working
> > group; it was more active when I started in 23003. I was not aware of
> > astroguard.ru providing data on optical behavior; I glanced at their
> > public reports and will have to check that out more thoroughly.
> >
> > Some ideas to discuss:
> >
> >    - If you'd like to limit your work to only Russian sats, no problem. I
> >    may take on a broader scope. As with JSC Vimpel's positional work, our
> >    independent analysis won't hurt.
> >    - Hopefully several others will join in the fun, and may have their
> >    own targets in mind.
> >    - I attached (1) a dump of my FPAS reports extant on satflare.com
> >    - The originating data is also in seesat-l posts from me as"BY F
> >    XXXXXX"(2)
> >    - Unfortunately, satflare stopped adding any more reports from anyone
> >    last year. Obviously, we would not want to use that for reports.
> >    - No problem here with future reports using PPAS format, but (as Leo
> >    once wrote to you, "I would like to renew also this list and attract
> >    more amateurs to search these objects." This might a good time, as
> sort of
> >    a reboot, to consider alternatives.
> >    - I'm going to start looking (and imaging) more variables and report
> >    them via seesat.
> >
> > A few requests:
> >
> >    - My attempt to make a query on Space-Track to identify CIS / Russian
> >    satellites that have not decayed and are not debris failed - do you
> hav e a
> >    list of targets of that ilk?
> >    - I also attached (1) my current extrapolation of the previous PPAS
> >    priority list (I always looked at Mike's site for this). It is just a
> >    worksheet in the sprawling behemoth that is my main satellite
> observing
> >    spreadsheet. Again, with a reboot, we could look at improving both at
> the
> >    priorities are assigned and how the list is presented.
> >
> > Notes:
> > 1) Attachments bowdlerized for list posting.
> > 2) My seesat posts titles refer to:
> >
> > OO-T-[Location]-MMDDYY
> >
> > OO = observer's initials
> > T = type of report
> >
> >    - D = decay (not yet, but soon I hope!)
> >    - F = FPAS - refer to Simone's description at: FPAS Reports -
> >    Specifications <http://www.satflare.com/fpas.asp>
> >    - G = flaring geosynchronous satellite reports
> >    - P = PPAS
> >    - R = remote imaging
> >    - S = steady (in a PPAS or FPAS format)
> >    - V = general visual observations
> >
> > It should also include:
> >
> >    - A = clear all day, clouds at sunset
> >    - E = equipment lost, broken, stolen
> >    - O = outreach at star parties where, once you're branded the
> >    "satellite guy" you are expected to know the name, owner, and launch
> date
> >    of every one that passes by
> >
> >
> >
> > Brad Young Visual:
> > 10 x 50 binoculars
> > Meade ETX-125
> > 22" f/4.2 UC Obsession
> > COSPAR 8336 =TULSA1 +36.139208,-95.983429 660ft, 201m
> > COSPAR 8335 =TULSA2 +35.8311  -96.1411 1083ft, 330m
> > Remote Imaging:
> > MPC I89 COSPAR 7777 38.165653 -2.326735 5150ft, 1650m Nerpio, Spain
> > MPC Q62 COSPAR 7778 -31.2733 149.0644 3400ft, 1122m Siding Spring, NSW,
> > Australia
> > MPC H06 COSPAR 7779 32.92 -105.528 7298ft, 2225m Mayhill, New Mexico USA
> > MPC U69 COSPAR 7780 37.07 -119.4 4610ft, 1405m Auberry CA USA
> > MPC 323 COSPAR 7782 -32.008 116.135 984ft, 300m Perth, WA, Australia
> > MPC Q67 COSPAR 7784 -33.3967 149.4917 2081ft, 650m Bathurst NSW,
> Australia
> > MPC W76 COSPAR 7785 -30.45 -70.75 5151 ft, 1570m Chacay, Chile
> >
> >
> >
> >
> > On Sunday, April 21, 2019, 7:15:15 AM CDT, Alain Figer <
> > alain.figer_at_gmail.com> wrote:
> >
> >
> > The PPAS has been an extremely efficient and fruitful project, for many
> > many years,  but it's seemingly dead now and that's obviously a pity.
> >
> > In my opinion, the 'astroguard.ru' russian site builds now the best
> > database (MMT data) up to date about photometric behaviour of satellites.
> > The only problem is they keep secret all the info about russian
> satellites.
> >
> > That's why I believe it would be of value to manage by ourselves a
> > specific database for russian satellites.
> > I am ready to take part enthusiastically to such a project.
> >
> > Regards
> > Alain Figer
> >
> > N.B. I published my first observations in the PPAS database in 1973 as
> AF.
> >
> > See my own database (since March 2012) about satellite observing :
> >
> > LIST OF BEST FLASHERS at:
> > https://www.flickr.com/groups/1983844_at_N22/discuss/
> >
> >
> >
> > Le dim. 21 avr. 2019 à 00:39, Brad Young via Seesat-l <
> seesat-l_at_satobs.org>
> > a écrit :
> >
> > There are quite a few PPAS type reports of tumbling objects and other
> > visually interesting satellites at:
> > http://www.satflare.com/fpas_query.asp
> > in a sortable database.
> > To stretch this thread a little bit, I stopped reporting to that site
> > because it doesn’t seem to be updating any new observations. Would it be
> > useful to resume making PPAS report in the old style? It doesn’t seem
> like
> > the PPAS list of interesting objects has been updated for quite some
> time.
> > I have a personal list that may be of some interest. If anyone has any
> > ideas or if interested and follow up please contact me off the list. With
> > the northern summer months, and, it will be a good time to revitalize
> > optical behavior observing work.
> > Brad
> >
> > Sent from Yahoo Mail for iPhone
> >
> >
> > On Saturday, April 20, 2019, 7:02 AM, tristan.cools--- via Seesat-l <
> > seesat-l_at_satobs.org> wrote:
> >
> > Thanks Alain, I will follow the discussion forums.  I knew about some
> other
> > Centaurs tumbling but to my knowledge it is rather rare but this is
> solely
> > based on my own observations.(my observations of Centaur rockets isn't
> that
> > large)  I have some trouble in finding updated PPAS records.  Are flash
> > periods still beeïng reported somewhere ?  During the last 10 years I did
> > some sporadic observations but didn't report anything anymore.
> >
> > gr, tristan cools
> > Belgian Working Group Satellites
> >
> > Op za 20 apr. 2019 om 11:36 schreef Alain Figer <alain.figer_at_gmail.com>:
> >
> > >
> > > Hi Tristan,
> > >
> > > > Most Centaur rockets have always been steady (according to my own
> > > observations)
> > >
> > > I am somewhat surprised by such a statement, since it is not what I
> have
> > > been currently noticing.
> > > See for instance several threads in my blog at :
> > > https://www.flickr.com/groups/satellites_artificiels/
> > >
> > > More exhaustively, the russian site 'astroguard.ru' (MMT data) lists
> > > multiple examples of flashing Atlas Centaur rockets.
> > > Concerning 2007-060B their graph shows how the rotation period has been
> > > decreasing for the last years ;  their last measurement is at 48.72s
> for
> > > the rotation period (twice your photometric period).
> > >
> > > See also the info by the same russian site about Landsat 4 1982-072A.
> > > They measured a rotation period at 16.7 s in 2018 but observed the
> rocket
> > > as 'Aperiodic'  in other circumstances too.
> > >
> > > Regards
> > >
> > > Alain Figer
> > > Gometz: 48.67 N ; 2.13 E ; 170m a.s.l.
> > > Vars: 44.57 N ; 6.68 E ; 1850m a.s.l.
> > >
> > >
> > > Le sam. 20 avr. 2019 à 10:28, tristan.cools--- via Seesat-l <
> > > seesat-l_at_satobs.org> a écrit :
> > >
> > >> Hi all,
> > >>
> > >> Most Centaur rockets have always been steady(according to my own
> > >> observations) but I was surprised to see 07-60B/32379 as a nice
> regular
> > >> varying object with a period of about 23s.  I think I will follow this
> > >> object to see it's future flash behaviour.  Maybe this has already
> been
> > >> reported...
> > >>
> > >> Another object, is the Landsat 4 satellite(82-72A/13367), no exact
> > period
> > >> measured but around 30s with sharp and round maxima.  In my old
> records
> > I
> > >> had a notice written that this satellite did have a mechanism to be
> > >> retrieved by the Space Shuttle.  Well, it is too late for that, but
> only
> > >> one satellite I think has ever been retrieved and re-launched I
> > remember.
> > >>
> > >> greetings,
> > >> Tristan Cools
> > >> Belgian Working Group Satellites.
> > >> _______________________________________________
> > >> Seesat-l mailing list
> > >> http://mailman.satobs.org/mailman/listinfo/seesat-l
> > >>
> > >
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> >
> >
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> >
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Received on Mon Apr 22 2019 - 06:38:30 UTC

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