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Satellite vewing predictions

Started by Rick, Jun 27, 2010, 08:56:18

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Rick

If you don't have a sky mapping program capable of giving you satellite predictions (and quite a few of them offer at least some such function) then you can always look online.

The easiest online place to get satellite viewing predictions (and quite a bit else) is Heavens Above. You'll need to set up an account and enter your position first time round.

Another place is Space Weather. Pick a location from the list offered by the UK tracker. It only gives predictions for a very few satellites, though.

There are tables of predictions for High Elms, updated a few times*1 each week, on my ISP website.
ISS - The International Space Station
NOSS - Satellites which travel in small groups (typically pairs or triplets)
Iridium - The Iridium satellites are usually pretty bright. Use Heavens Above to get flare predictions.
A selection of hopefully*2 visible satellites

These are tables set out as follows:

Ground Station    : High Elms, Farnborough, Kent, England   ---   JO01AI
Time Zone         : UTC (+0.00 h)
                           in eclipse *  in daylight o
                                      ^              ^
Date       Rising at    Peak elevation      Setting    Height Satellite
Y M D  Time      Az.  Time      Az. El  Time      Az. (peak) Name
======  ========= ===  ========= === ==  ========= === ====== =========
100625  21:31:14  222  21:35:53  149 26  21:40:39   77        ISS


In the row for ISS shown above:

  • Date is (20)YYMMDD so that's 25th June 2010 in this case.
  • Satellite rises at 21:31:14 UTC (which is 14 seconds after 22:31 BST), but that's assuming a nautical horizon, so chances are you won't see it for a minute or so after that. You want to be looking towards the south west (bearing 222 degrees from true north).
  • Satellite is at its highest elevation at 21:35:53 UTC, at which point it'll be on a bearing of 149 degrees, and it'll be 26 degrees above the horizon (so probably not the best of opportunities).
  • By 21:40:39 UTC it will have vanished somewhere off just north of east.
  • If any of the times had an asterisk after them then the satellite would not be illuminated by the Sun, so wouldn't be visible.
  • If instead they had an 'o' after them then the Sun would still be above the horizon...

*1 New uploads early on Wednesday, Friday and Sunday at present...
*2 Some of them may be very faint, and a few are based on unofficial elements which may be less accurate...

PhilB

Heavens Above also enables you to print a full sky chart for your location. This gives you a better idea as to where to look and also how high the satellite track will be. The prediction above, for example is for a low track passing through Libra and Ophiuchus. The next pass at 23:24 through 23:34 is better, passing between Draco and Hercules and, therfore, more or less straight over head. Note these passes are for my set location (Dartford), and are good for a radius of about 10km (6.2 miles), depending on the orbital height of the satellite. It is possible to set up your Heavens Above account for more than one location if you wish and then select the one from which you are going to observe.
"Never worry about theory as long as the machinery does what it's supposed to do."  Robert A. Heinlein

Rick

I've changed ISP, so the links in the top post have all been modified. The old links may still 'work' (after a fashion) but the files they return are a month or so old now, and I can't get at them to do anything about it. (That was the first hint I got that the ISP I've been using for twenty-mumble years was in the process of rolling over and going under...)