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Update on the DRA Project

The project to determine the orientation of the rotation axis of flashing satellite has taken a promising start. Here is an overview of the observations received so far. Indeed, and thanks to Walter Nissen, Bj"orn Gimle and Mike McCants for their observations received in the last week. So far we have multiple timings of the following objects :

April 15, 85- 41 B (#15752), 4 timings by Walter
April 19, 95-  2 D (#23466), 36 timings by Mike
April 21, 95-  2 D (#23466), 38 timings by Mike 
April 21, 92-  8 B (#21876), 16 timings by Bjoern
April 21, 93- 59 B (#22803), 6 timings by Bjoern
April 26, 85- 41 B (#15752), 18 timings by Mike
May    7, 94- 24 B (#23093), 22 timings by Walter
May    8, 94- 45 B (#23190), 30 timings by Walter
May   10, 92- 73 B (#22208), 16 timings by Walter
May   10, 82- 66 B (#13302), 4 timings by Bjoern
May   15, 82- 40 J (#13168), 7 timings by Bjoern

I hope some of the Benelux-observers will send me some data through snail-mail. The project is open to other observers than Walter, Mike and Björn ! In any case, thanks to the observers so far. I haven't had time yet to analyze the data, but it is clear that we will need more coverage to fulfil the goals of the project. I will wait another month and if the coverage remains at this level, I will limit the number of satellites to be followed. More next month.

So, I would appreciate more data of these objects. I know conditions may not be right for making long observations for some of you, but we do maximalize our chances of determining the rotation axis if we have lots of timings. The program currently consists of these objects :

95-  2 D, C1 Tsikada, #23466
94- 61 B, C1 Kosmos 2292, #23279
94- 45 B, C1 Kosmos 2285, #23190
94- 41 B, C1 Nadezhda 4, #23180
94- 24 B, C1 Kosmos 2279, #23093
93- 59 B, J1 Zenit Kosmos 2227, #22285
92- 73 B, C1 Kosmos 2218, #22208
92- 64 A, Freja, #22161 
92- 38 B, SAMPEX Scout rocket, #22013
90- 36 B, C1 Kosmos 2074, #20578 
90- 23 B, C1 Kosmos 2061, #20528
87- 74 G, F2 Tsyklon Kosmos 1875-1880, #18340
86- 37 B, C1 Kosmos 1745, #16728
85- 41 B, C1 Kosmos 1655, #15752
84-109 B, C1 Kosmos 1605, #15360
83- 69 J, C1 Kosmos 1473-1480, #14179
82- 40 J, C1 Kosmos 1357-1364, #13168
70-106 B, Delta/CEP 1 NOAA 1, #4794

Regarding secondary maxima, you can record them and report them, as long as you indicate that they are secondary maxima. I may (or may not) use them in my analysis later on. Usually secundary maxima make the results worse, since they are (I think) caused by flashes of the ends of the cylinder. The software does not handle flashes on the sides. But, in fact, in some cases timings of the secondary maxima may help me in deciding what 'index' the flashes you saw had.

Björn also remarked the following :

To reduce the risk of transcription errors, I would prefer to report the flash times as actual seconds reading on the stopwatch, and the actual time of the last full minute on the stopwatch before the time of first observation, i.e.

   21   21   27 25.0   16
 58.75  0
 73.00  1 ....   
instead of 
   21   21   28 23.75  16
  0.00  0
 14.25  1 ....

I agree with this completely, the software already allows for entries in that format. Next month, hopefully some first results.

Bart De Pontieu



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Next: Cloud around Spot Up: Flash 93 Previous: Visibility of STS



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