Hi All It is quite refreshing to see the positive response to Ted's message 20 Dec 08:16 re the possible loss of TLE's for most objects. > Kevin Fetter wrote: >> This doesn't look good. > It could be just the motivation we need to greatly advance our > capabilities. My initial reaction to Teds announcement was did it really matter if we lost this data and would it be worth the effort to try and generate our own. I only concentrate on the satellites in CLASSFD.TLE because this is where I feel there is a need for observations and rarely looked at other satellites - Id like to but one cannot do everything. However I now look at this possible problem as a challenge as Ted said we need to greately advance our capabilities and this, to me, is where the pleasure of the hobby comes from. >> This might put a dent in my satellite observing:( > Why should it not have exactly the opposite effect? I agree with Ted - it opens up a whole new playing field. >There was a burst of software development in the mid to > late 1980's, as reasonably powerful PCs became affordable > for home use, but we have not fully >exploited the enormous power of present day PCs. I started tracking satellites in 1960 when there was no such thing as a pc, internet etc or readily available orbital data. I learnt a great deal from the publications of the Volunteer Satellite Tracking Program, mainly those of the late W.P.Overbeck (Bill) and spent so much time cranking a hand desk calculator and using log/trig tables that I wasted a year at University. Bill tried to encourage amateur observers to maintain their own orbital data and his publications showed that it was indeed possible for a single observer to maintain elements for at least 30 satellites that would be accurate for quite a long time- better than what we get now with SGP4 models ( which of course did not exist then) using a hand calculator. Most of us have PC's and I think it not unreasonable to think that a single observer could now manage 300 satellites or more and only have to observe each one a few times a year. > I see a need for a similar program for planning observation sessions. > ObsPlan would highly automate the process of target selection and the > generation of finder charts. > It would support the use of priority lists. this I think is an excellant idea. > having ObsPlan determine where you should stand to observe a > particular object. this wont work with me - my telescope pole is buried in concrete:-)) > Imagine always intercepting satellites when they pass good > reference stars. would be nice! > Could be used to choose among multiple coincident targets of similar > priority. same comment. > While on the subject of improving support for observers, there is a > crying need for a better method of timing than the stopwatch. this was always a bugbear for me - I could seldom find time signals to use my stop watch with when I needed it. I eventually solved this problem by setting up my own time "standard" which I regularly check/set against radio time signals whenever I hear them. Today one could use the pc to check against an atomic standard provided one had an internet connection. Unfortunately this service is only useful for tracking if you have a permanent internet connection which some of us dont have for various reasons. None of my pc's keep time accurately enough to be used "as is" and I tried various programs to "rate" my pc's but overall wasnt too impressed with the stability of the pc clock. > We need to adopt orbital models that can fit observations and make > accurate predictions over very long arcs - months and years, instead > of days and weeks. this is the crux of the matter... the better the orbit model the less observing needed per object and the more we can track. > Greg Roberts has led the way on the hardware front, with his > computer-aimed video system, and Peter Wakelin and Rainer Kracht are > getting great results with still cameras. This is another area of > huge potential. After doing video observing for about three years now there is no way I could go back to using binoculars/stopwatches - I am convinced that this is the way to go... > It would be great if affordable systems could be built for use by > non-hardware experts. yes this is the problem. My system has not cost me a fortune because I used what I could find lying about. I am "fortunate" in that I have a lot of useful stuff "lying about" because of my interests in astronomy and pc's as well as being a radio amateur so the actual "out-of-pocket" expenses in building my system were actually very small. In addition I have some electronic knowledge, an astronomical background and a metal lathe and milling machine which all helped. However for someone who has none of the items the cost is not negligible. At a minimum one needs a low light level surveillance camera, a composite video monitor, a video tape recorder and a time stamping system where the actual time of the observation is recorded onto the video image. I seldom use my system in the auto-track mode because of the vibration visible at long focal lengths, so instead use my mount purely as a "GOTO", ie at 16h35m point at az 150.3, el 35.2 etc driven by a computer program written by Willie Koorts and freely available along with full details of how to build such a system. (http://www.saao.ac.za/~wpk/CoSaTrak/cosatrak.html) When tracking satellites in relatively stable orbits - ie small time errors, I believe I could use my system in an automatic mode and I could have it run unattended as long as there is video tape in the VCR. Teds OBSPLAN would select the satellite as well as a good field - I need 2 stars anywhere in the field and as long as the mount has a minute or so to go from any one position to any other position maybe as many as 20-30 satellites an hour could be tracked and recorded.The computer program can also record where the camera was pointing at any instant so star field identification should not normally be a problem. For orbital element maintainance on most satellites one position per pass should be adequate. Unfortunately the measuring is still manual :-(( The comments by George Roberts ( no relation that I know off!) are also worthy of serious consideration as the work load for only a few people is considerable. An excellant system currently exists for the approximately 100 satellites I concentrate on but 2000 satellites or so may be a different matter. The input by Bradley P.Allen is also worth while - some of it is above my head and the only point I can disagree with is the proposal to move the discussion to the Satobs-sw list. The discussion on what we are going to do if we loose the TLE data is very relevant to SeeSat and should get the widest possible exposure as it concerns all SeeSat'ers. Sorry for the long winded discussion but I think the more ideas we can put into the "melting pot" the better will be our stategy. Cheers Greg ----------------------------------------------------------------- To unsubscribe from SeeSat-L, send a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@satobs.org List archived at http://www.satobs.org/seesat/seesatindex.html
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