Wayne > Thanks for the explanation of your post. I have two questions whose > answers may > be involved. > > First, what is the history of your choice of these four Noss > satellites? I > haven't looked at your other posts in view of this but I assume they > are also > observations of the same satellites? > The NOSS launches are interesting because they all produced three satellites which for a few years flew in a formation which looks like a triangle from the ground. There was a leading satellite, a trailing satellite following 16 seconds behind, and an outlier. In the case of the type 1 launches, there was another satellite always called A with a slightly higher mean motion. The much brighter type 2 launches have a smaller triangle. > Second, I see six observations for the first object: > > > IntlId SiteYYMMDDHHMMSSss Sss TCHHMMmm DDMMm Mm E > > 8401204267500081422175832 010 12173764 +48324 2 5 > > 8401203267500081422181718 010 12173604 +48495 2 5 > > 8401206267500081422190931 010 12202443 +68212 15 5 > > 8401203267500081422203486 010 12013070 +66068 15 5 > > 8401201267500081422295428 010 12163423 +57481 3 5 > > 8401201267500081422300646 010 12164100 +62180 1 5 > I think you have misunderstood my posting. There are three objects here, namely 8401204, 8401203, 8401206 and 8401201. These correspond to the leader, 84-12D, the trailer 84-12C, the outlier 84-12F, and 84-12A which is currently in the process of slowly overtaking the others. > So the observations, presumably of the minutest positions of the > object, are 19, > 52, 85, 20, and 12 seconds apart. Not to mention of course that your > next set > of observations starts 5 minutes later. How do you physically get > this many > observations? Do you have a single skychart printed out with > landmarks already > planned for marking the positions? You have a stopwatch, the chart > and a pen, a > light, and a set of binocs, at least. > I use the star charts from Atlas Coeli by Becvar, glued onto sheets of cardboard. Since it's rarely possible to observe a satellite south of -25 deg Declination from the UK, there are only 11 charts. Before observing, I make a schedule of the satellites I plan to observe at the head of a sheet of paper. From the schedule I mark the tracks of the next batch of satellites on the appropriate charts in pencil. Then I go in the back garden (US yard), and sit in a deck-chair with the charts on the ground beside me. Binoculars, split-action (Casio) stopwatch, red torch and pencil complete the equipment. The stopwatch runs continuously, showing a time within a few seconds of UT. I can make two timings (a split time and a lap time) before having to read the watch. I find a position in the sky where the first satellite is going to pass, and wait for it to arrive, counting seconds to the predicted time to try and avoid being distracted by an early stray. When the satellite passes a memorable star or pair of stars, I make a timing. I may follow it for 30 secs or so and repeat the process. I then make little sketches on my schedule of the relevant stars and where the satellite was in relation to them, and record the times. This takes about 20 seconds, and then I'm ready for the next satellite. In the case of 84-12D and C, I was able to use the same star group. I had memorised where F would be a minute later, and in fact got a position on it 52 seconds later. I've discovered that the third observation is NOT of 84-12C and may be a stray. 84-12A came along 9 minutes later, not 20 seconds as you surmise. > Do you have three arms? :-) > No, but I have lots of practice. I started using binoculars and stopwatch in 1962. Also I have two deckchairs so that I don't have to keep moving them around the garden. > How on earth do you get all this on the night in the light of a full > moon? > By using 20x80 binoculars which I can usually hold steady enough with the chair supporting both elbows and my head. And by being fortunate enough to live in a part of the world where winds between SW and NW bring nice clean air off the Atlantic. The limiting magnitude for satellites was about +8.5. Regards David. -- The Information contained in this E-Mail and any subsequent correspondence is private and is intended solely for the intended recipient(s). For those other than the recipient any disclosure, copying, distribution, or any action taken or omitted to be taken in reliance on such information is prohibited and may be unlawful. ----------------------------------------------------------------- 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
This archive was generated by hypermail 2b29 : Thu Aug 17 2000 - 02:25:37 PDT