Wayne Hughes wrote: >If this question is indeed a FAQ that has no current answer, I'd be glad to write >a summary as an answer as proposed below. First, let me say that there is some information in the FAQ Chapter 7: (http://www.fc.net/~mikem/faq) >7.0 Satellite Observations: More Than Just Looking An introduction. >7.1 Positional Measurements This section says that positional observations of certain satellites can be sent to the RGO for analysis, but I do not believe that this is still true. There is no mention of the George Lewis' IOD ObsEntry program since it became available after this faq was written. (ftp://ftp.fc.net/pub/users/mikem/obsentry.zip) >7.2 Flash Period Timings This section covers the observation of flashing or tumbling objects and how to send observation in PPAS format to the coordinator. >7.3 Determination Of Rotation Axis (DRA) Project I don't think that the DRA project is currently being actively ----- In particular, the following paragraph appears near the top of this chapter: >During the last several years, a unique application of >positional measurements has become more popular, i.e., >the determination of the orbital elements of USA spy >satellites. Orbital elements are required to predict >the passage of satellites. USSPACECOM distributes >orbital elements of virtually all satellites, except >for secret USA military satellites, such as the KH >(KeyHole) and NOSS satellites (three satellites that >move together in tight formation). A rather informal >worldwide network of persistent amateurs has specialized >in tracking these objects and calculating the orbital >elements themselves. This celestial detective work >certainly gives an additional stimulus to positional >measurements. But there is nothing else on this subject in the FAQ, so I would consider it incomplete in that respect. There are 84 objects in the file "classfd.tle". (http://www.fc.net/~mikem/ftp/classfd.zip) These objects are also in "mccants.tle" and "alldat.tle". Nearly all of these elements were generated by me. I receive observations of these objects from quite a few people and I use the observations to update these elements. >I'm not even sure whether there is a strong demand for more >observers or whether the observing efforts are more or less saturated. Since it is clear that we have "lost" some objects, there are situations in which we need more observers. In particular, observers at lower nothern latitudes and southern latitudes could have observing opportunities at times other than the prime times for the high northern latitude observers. That being said, some of the objects are quite bright and are in low-drag orbits, so their predictions will be off only a few seconds after a month or more and they are easily re-acquired. Other objects are quite small and usually quite faint. They can be seen on favorable passes in my 12x80 scope, but are normally seen under dark skies with 20x80 binoculars or a telescope. And the most difficult are the ones that are both small and faint and have a non-zero drag term. Also the 12 hour eccentric and near-geocentric objects almost always require a telescope and the use of a special program that computes solar, lunar, and the Earth's longitude-dependent gravity terms. So one thing I need to do is write a web page that breaks these objects down into their "classes" and describes each of those classes and their observational requirements. We also need better communications about objects that are "about to be lost". >But could there be an >occasional posting, perhaps made along with Bart's summary of the list's >mission, of a sort of a FAQ that orients people interested in doing this kind >of thing, or directs them to a page where this is specifically and in detail >discussed? Of course we got some interesting attention in the May 15 issue of Time magazine and we have kept this operation fairly "quiet" in the past, but it's not really a "secret". Can you be more specific about any other questions you would like to have answers to? --------- > 16609 00205.719576 +1 > 16609 00209.005624 flared to -2 > 16609 00213.775687 +2; reddish-color > > Just the satellite, date and time observed, and a simple remark about the > pass. I think that would be a great resource. But I do realize that it > would take a lot of time to do it, keep it current, but if several people > combine their efforts, it could be possible. There have been catalogs of "observed optical characteristics" in the far distant past when there were not all that many objects to be seen. Personally I have been known to look at or for something "more interesting" when Mir was passing by. :-) There are now several thousand observable objects. There are many observations in the PPAS. But my criticism is that without knowing the range and phase angle (and possibly other things), an "observation" that object 12345 was 7th magnitude and steady is not necessarily all that useful. Perhaps a slightly better approach would have the observation include both the observed magnitude and the "intrinsic" magnitude as determined by a (which one?) formula that corrects for range and phase. And, of course, such a catalog needs to be "searchable" in some sense. Mike McCants ----------------------------------------------------------------- Unsubscribe from SeeSat-L by sending a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org http://www2.satellite.eu.org/seesat/seesatindex.html
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