Re: tumbling rocket and satellite

From: Marshall Eubanks via Seesat-l <seesat-l_at_satobs.org>
Date: Mon, 22 Apr 2019 10:19:33 -0400
On 2019-04-22 07:37, Alain Figer via Seesat-l wrote:
> 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.
> 

The asteroid community does have a light curve database for asteroids

http://www.minorplanet.info/lightcurvedatabase.html

which might serve as a template for this.

Regards
Marshall Eubanks


> 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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Received on Mon Apr 22 2019 - 09:21:33 UTC

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