Re: List of Bright Satellites - Why is it prepared Manually?
Dave Ziemann (dziemann@easynet.co.uk)
Sat, 14 Dec 1996 11:47:27 +0000
>>
>> Greetings!
>> A few days back I posted a request for information on satellites
>> visible from mildly light polluted skies with the naked eye.
>
>Am I alone in thinking that this is a cart-before-the-horse approach?
>In other words, "figure out a list of satellites we might be able to
>see, then run them through prediction software to see which ones turn
>up".
>
>I am wondering why, with all of the satellite-prediction software
>we have today, it is still necessary to ask this question, especially
>since magnitude estimates can be found in Ted Molczan's elements
>file. Why doesn't one of these programs simply run through the
>elements list, calculate a predicted magnitude, and if it shows
>up brighter than a predicted magnitude, print it out? So far as
>I know, only QUICKSAT does something close to this. However, it
>uses its own file of predicted magnitudes which are actually
>'greatest ever' brightness rather than 'expected' brightness,
>which results in a lot of predicted passes that are not seen.
>Is there some other software package that gives this information?
No! You are not alone. I have been lurking on this list for a couple of
months, a satellite newbie trying to get into this exciting field. Until
your post I assumed I was being stupid. For the novice at any rate, it seems
frustratingly difficult to get simple information.
What a newbie wants to know (and perhaps an oldbie also?) is "what can I see
tonight?" not "hmmm...I have a sudden inexplicable urge to look at Cosmos
1741 r - I wonder when it's visible?".
For me, the satellite software approach cannot take off (sorry) until all
current element sets are easily and transparently available to the user from
a definitive source. So the approach I use is to print the marvellous page at
http://www.physics.ox.ac.uk/sat/pred/London/predall
(I live in London). But even here the information is ordered *by satellite*
not by event, so I have to scan through the list looking for the right
day/time, checking to see if the elevation is great enough, and if the pass
is sunlit (it took me a while to get to grips with that stuff, but I can
read it now). Then I have a satellite number, but, frustratingly, not a
satellite name (I find it hard to "bond" with the small integers).
May I briefly describe my fantasy satellite software? I cannot see why *any*
user input is required after starting the application. Assuming that I have
already configured my location and UTC-offset, and that the application
comes with nice default "sight quality" cutoff values (eg for
magnitude/elevation/visibility-time), then I want to immediately see a
summary list of forthcoming time-ordered events, each event having a single
local date/time and a satellite name. If I press one button I want expanded
information (the more detailed location/visibility data).
The list that I see can be "filtered" according to various criteria. For
example, one set of buttons will let me increment/decrement each of the
"sight quality" values, in each case refreshing the list in order to reflect
the new criteria. Other filters could be established by the user (eg
favourite satellites, flashing satellites). I'm sure the knowledgeable ones
here can identify the important filters.
(I feel sure that if "Bill" were into satellites it would be done this way <g>).
My comments are intended to be constructive criticisms, I hope no-one is
offended by my presumption. Although I am a satellite neophyte, I earn my
living as a software developer. The currently available software is
fantastic in terms of speed and accuracy, but does make certain assumptions
about the level of technical skill and motivation of its users.
glad to have "broken cover"
regards
Dave Ziemann