Longish Comments Re: Bright sat list / software

Ed Cannon (ecannon@mail.utexas.edu)
Tue, 17 Dec 1996 03:14:01 -0600

    Longish Comments (including hopefully helpful hints for other 
    newbies) on the discussions regarding bright satellite lists, 
   predictions on the Web, prediction software, and orbital elements

In general, one issue I've seen in every group with which I've ever
been associated (or even aware of) is the gap between oldtimers and 
newcomers.  In almost every case, newbies really need some help from 
oldtimers (some/many of whom are willing to help newbies), but newbies 
also have to take some initiative in order to get the information they 
want.

As one who just began doing this satellite-watching activity a little 
over 9 months ago (but who has by now seen scores of objects thanks to 
great software and fresh orbital elements as well as lots of help from 
Mike McCants -- and frequent observing opportunities through his 
telescope -- and quite a few clear nights [and even a few mornings]!), 
I can relate to newbies' questions, and their reluctance to even post 
them to SeeSat.  But I also feel that I can offer some tips on what 
I've discovered or been directed to in the last 9 months.

PREDICTIONS ON THE WEB

For someone interested only in seeing a few of the very brightest 
scientific payloads (Mir, Hubble Telescope [HST], Upper Atmosphere
Research Satellite [UARS], Compton Gamma Ray Observatory [GRO], and 
US Space Shuttles [and the Cosmic Background Explorer, COBE, which is 
not a bright object]), and who has a forms-capable Web browser, the 
"SatPasses" site is excellent:

  http://ssl.berkeley.edu/isi_www/satpasses.html

It's now providing fresh, accurate daily pass predictions for more 
than 70 cities in the US and Canada.

NASA provides predictions (sighting opportunities) for Mir and Space 
Shuttles for lots of locations.  Sky & Telescope Magazine's Web site 
provides Mir predictions for cities all over the world, as well.

Some locations (Austin, Texas; southeast Washington State; Washington,
DC; southeastern Virginia; Europe, etc.) are fortunate enough to have 
daily predictions published frequently by industrious individuals.

To my knowledge, the closest thing on the Web to a complete, user-
specifiable prediction service is the "Earth Satellite Ephemeris
Service", which now has two sites (requiring forms): 

  http://marx.as.utexas.edu/sat.html 
  http://www.chara.gsu.edu/sat.html  

If you get its predictions for your location for a particular date
(or dates), and your sky is clear, you will likely see one or more 
satellites (especially if you use binoculars).  However, ESES does 
not include 100% of orbiting objects visible to the naked-eye.  Also, 
it seems that its predictions aren't quite as reliable (for reasons 
I, as a relative newbie, don't understand) as those provided by my 
next recommendation.

SOFTWARE

Within a couple of months of when I began to try to get predictions 
to see satellites as often as possible, I had gotten and begun using 
Mike McCants' Quicksat (DOS version).  Quicksat provides predictions 
for any selected time period (from minutes to weeks, if you wish 
[I've projected EGP, Mir, and others weeks out in the future, just out 
of curiosity.]).  You can select times only in the morning, only in 
the evening, or all night (or round the clock).  You can specify a 
magnitude limit adjusted to naked-eye, binocular, or 90-inch telescope 
(!) viewing.  You can choose to view objects from the ground up, or 
only within two degrees of the zenith, if you wish.  Or you can 
specify only objects that will be visible through your favorite window 
or skylight, or through a box blocked out by your roof and trees or 
buildings!

I know there are other good software packages, such as those that
provide graphical interfaces and/or output.  (If someone ever writes 
a good graphical interface for Quicksat and/or a Web-form prediction
generator based on it and/or graphics using its predictions, he or she 
likely will be nominated -- by me if no one else -- for the SeeSat 
version of a Nobel prize!)  However, as I'm comfortable with DOS and 
its text output (after I learned what "azimuth" was!), Quicksat works 
for me.

ORBITAL ELEMENTS

It seems to me there's little or no reason for people wanting to see 
naked-eye or binocular visible satellites to have to work very hard 
at all to get up-to-date elements at least once or twice a week.  

Once a week, Ted Molczan produces a new set of elements for more than 
1,000 objects, and then he and others make those elements available 
through different means in various places on the Internet.  (With 
software that lets you filter for brightness, you will get predictions
only for objects bright enough to get through the filter during the
specified time period.)

If you want elements more than once per week, then you can get Mike 
McCants' LEO.TLE, which includes all of Ted Molczan's objects except 
US classified satellites.  Mike also provides a frequently updated 
(several times a week) file named RECENT.TLE containing elements for 
the most recently launched objects.  Mike also makes available orbital
data for over 1,000 high-orbit objects (ECCEN.TLE for eccentric 
orbits, and GEO.TLE for geocentric ones).  By the way, Mike also 
provides several different types of links for getting Molczan's 
elements (zipped or not) -- AND links to several software applications 
(including, of course, the most current version of Quicksat).

  Web -- http://www.fc.net/~mikem/tle.html
  FTP -- ftp.fc.net/pub/users/mikem/

(Now, I hope Mike's ISP doesn't get a sudden traffic jam of people
seeking satellite elements and/or software!)

And, if you want to get elements that are just hours (minutes?) old, 
you can connect to the OIG BBS (via telnet or direct telephone
connection) and get them -- AFTER you spend a while figuring out how 
it works!

Finally, if you want elements for 4,000 or 8,000 objects, then you 
probably already know where to find them!  (But if you don't, ask
and someone on SeeSat will tell you.)

CONCLUSION

With some effort and some help, just about anyone should be able to
get satellite predictions and use them to see satellites.

So, may your night sky always be clear (which means you'll probably 
have to settle for some rainy days)!

Ed Cannon
ecannon@mail.utexas.edu
Austin, Texas, USA
30.30N x 97.73W (somewhere between home and office)