RE: Titan 4

Ted Molczan (molczan@fox.nstn.ca)
Wed, 10 Jul 1996 11:50:30 -0400

>Ted Molczan writes: 
>> I have plenty of experience observing very poor passes, mostly with 
>> success, so I am inclined to believe that the object has made a 
>> major manoeuvre. 
 
>You must be a better observer than I.  I have frequently been completely 
>unable to locate objects at poor phase angles (i.e., backlit, i.e., poor 
>solar illumination).  The Tselinas and Okeans are notorious in this 

I think it is a matter or experience and equipment.
The experience comes from having the *need* to
observe at low elevations, poor phase angles
and bright twilight from time to time - sometimes
with all three conditions at once! When I am
observing casually, I pick the easiest to use,
overall most convenient passes. But when it is
something important to me, the rules are more like
in golf - play the ball where it lies! So I have
felt the need to look at poor passes, and learned
to cope. And one of the best ways to cope, is to
use mounted 11x80 binoculars.

A mount is useful for any aperture optics, because
it affords a steady view, essential for spotting
faint objects. Also, long searches, like the one
I performed last night, would be too tiring if I
had to hand-hold the binocs, plus I would lose
my position every time I had to consult my charts
for the next aim point (in search mode, I am
trying to stare constantly at the orbital track,
but it moves across the sky due to the Earth's
rotation, so I have to periodically adjust my
aim).

The large aperture helps seeing faint objects,
and also lots of faint reference stars, essential
to making very accurate positional observations.

>gard, but hardly unique.  I have remarked before that the concept of 
>phase angle is based on a theoretical rough-textured sphere, but that real 
>satellites are boxier, more shadowy, and shinier.  In fact, I'm not sure I 
>see how the concept of phase angle applies at all to the typical tumbling, 
>shiny rocket body?  (Mike, if you'd like to give us the benefit of your 

I use phase angle only as a rough guide, to help
me select the earliest reliable intercept point.

>I've kind of lost track of which elsets for the T4 are worth using, an 
>occurrence that has happened to me a few times in the past year or so.  I 
>think I could do a better job of picking my spots if I had more guidance 
>on this.  I'm not sure I'm unique in this regard. 

I think that is just a matter of closely following
the Seesat-L message traffic. The greatest potential
for confusion arises when more than person is 
producing elsets. For this launch and the recent
NOSS 2-3 launch, it was mainly Rainer and I who
produced elsets. I am fairly good at producing 
preliminary or search elsets, but not as good at
doing differential corrections. Also Rainer has
better access to several excellent European observers,
who do not have Internet accounts. So I am happy
to let Rainer carry the ball producing the most accurate
orbits. Sometimes, when a manoeuvre has occurred, I
will issue my own elset, just to be certain that
observers know there has been a change, and have
a reasonable elset to work with. After all, Rainer
and live far enough apart, that one may be asleep
when another is awake, so sometimes it is best not
to 'wait for the other guy'.

So I think that Rainer and I and other analysts
do a reasonable job coordinating our efforts,
more by instinct than design. But, having said
that, I sometimes the orbital updates come pretty
fast, and it can seem confusing. My advice is to
take the most recently posted epoch, from the 
analysts/observers you know and trust best.

> In my case, it is my 
>physiological deficiencies which make it all but impossible to hold a 
>posture for a lengthy period, but for others it may be lack of great 
>patience. 

Well patience is a virtue, and that is certainly
so with our hobby. I make no special claims in that
department. In fact, next to being over-worked,
the other main reason that I gave up regular
observing, was my impatience with the weather
ruining a high percentage of my observing sessions.
To have observed for nearly 40 years, and produced
over 200,000, or is it 250,000 observations, Russell
Eberst must have the patience of Job - not to mention
a great deal of dedication.

Happy hunting!
Ted

P.S. - it is still possible that 96038A has not
manoeuvred. I am not infallible, so I am awaiting
more reports. I am about 90 percent confident that
it has manoeuvred.