I did not receive all the text via one of my emails (too long), so I have tried to keep this short. Obviously, this is all IMHO only. >Priority system I agree with this section completely. >Variable brightness >The PPAS is about these tumbling spacecraft. What we care about is the tumble period regardless of the nature of the >variation. This statement may represent a fundamental difference in why I observe vs. what PPAS is intending to achieve. My observational reports also try to describe interesting objects that may be worth a look, if only for enjoyment or curiosity. >Sometimes I get observations within which a variation is reported while there is only one maximum stated. Then I do not >know whether this is the normal brightness variation of steady objects or variations due to rotation. I try to excise any observations that are obviously phase angle related only. Therefore, if the maximum occurs late or early relative to culmination, it is reported, but not if there is only one maximum and it is near culmination. This is by its nature a tricky call. >Processing of the observations I elaborate on editing of the observations and distribution below. >Format of PPAS-observations. I will review the referenced web page and see if have adhered to convention. >Note references No comments. >Reporting of the end time No comments. >Reporting of individual timings >My conclusion: You need not to include them if regular. With irregularities they can be very useful when determining a >period. Agreed. I rarely do this, but have records on many if the need ever arises. >Detection of a flash period...I now follow a satellite with variable brightness as long as possible during a transit. Agreed, although at my site I have some spots with trees, etc. as I'm sure others do. >There are also many small satellites with flat surfaces causing faint flashes. Such satellites can be seen steady, show >some flashes times and then become steady again. These are not really PPAS objects. Is there an "official" definition of a PPAS object? >Observations per satellite We need more observations of faint objects - agreed. >Flashes and flares >Operational Iridium cause "flares", tumbling Iridiums cause flashes. Iridium flares are predictable, flashes are not. I >suppose that flares caused by Skymeds, Key Holes and Lacrosses can be predicted as long their attitudes can be >predicted. Almost always such a satellite will flare under the same conditions in the same area of the sky (at nearly >the same elevation and Azimuth). I'm not sure if this means I should continue reporting these flares or not. I cannot (yet) agree that all these objects flare at the same attitudes, and would propose that reported observations are the only way to verify any predictability. >In summary: No comments. >Last Note >All observations are scanned, but not all will be written to the PPAS database. The less suitable observations are kept >in a separate file. Possibly this file will be made available to other observers. This is probably the only real issue I have with the entire note. If I take the time to post the observations, I would like to think they are not discarded. If they are unsuitable for PPAS (flares and flaring geosats spring to mind) then I hope there will be a publicly available database where these reports are kept, else, what's the point of posting them? I can just keep them to myself and not worry about them being discarded. This hobby, perhaps as much as any other, is completely dependent on symbiotic relationships not only due to geographic limitations, but due to lack of public data (classified objects) and a dearth of data (optically active objects). I hope that any data that's received is at least kept, perhaps summarized, as it is now. I know not all of my postings are useful - either positional or PPAS data. But unilaterally disposing of data is not the answer. I rely on classfd.tle for positional predictions of classified objects and PPAS assignments (plus my own notes and Mike's) to determine what to look at. If PPAS data becomes less inclusive, it will become less useful. The PPAS database and priorities do not predict optical behavior in every situation per se, but it is a place to start. Brad Young TULSA 1 COSPAR 8336 36.1397N, 95.9838W, 205m ASL ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
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