Helping newcomers - was:Re: Coursen magnitudes

Bjoern Gimle (
Thu, 25 Jul 1996 22:57:35 +0200 (MET DST)

Lew Gramer <> wrote:
>Just curious about what spawned this particular personal attack? Is this the 
>kind of scrutiny most newer observers are generally subjected to? (For the 
>record, I'm a regular meteor observer, and I don't know my long and lat to 
>better than an arcminute either! I guess it's more important for sat obs... >?)

Although not involved in the previous discussion, I feel an
obligation to try to reasure newcomers on the good will and
practices of seesat-L oldies.

Rob wrote :
>I gave him Mir, Lacrosse, EGP, Zenit and many other predictions for several
>years by telephone, but he never made any effort to record anything useful
>from his observations.  I finally stopped taking or returning his calls
>because it was a 1-way street.  For a few hundred bucks (then), he could have
>purchased a minimal computer and done his own predictions.

(Ted mentions nine years !) Jay has also commented. 

I think this is a key point. I, and most SeeSat-L members,
try to be helpful to NEWCOMERS ! 

I have also helped friends for long periods with predictions.
But if they have seen satellites for a year, and not learned how to 
report rough positions and motion for objects that do not appear in their
predictions; or accurate positions for nearly correct predictions; or run
their own predictions (even if they have to get orbital element sets
via diskettes from me); or use prediction utilities on the Web, like
Earth Satellite Ephemeris Service:
- I would find it difficult to keep my service level up !

And concerning accuracy of observer's position : 
This is tied to the prediction and observational accuracy - satellites
move up to 8 km/second, and few predictions are accurate to less than
a second. This corresponds to about 0.07 degrees of latitude error, or
slightly more in longitude. And at an average satellite range of 450 km, say,
this amounts to a positional error of one degree.

So, for prediction purposes, and for detecting satellites that are new,
or have changed their orbit, even a tenth of a degree, or larger error,
in latitude can help other observers identify and track the object !

For amateurs (like me) who find it tedious to read prediction tables,
and converting the mentally or mechanically to star charts, and then
reversing this to record observations, I suggest using a graphical program
like SkyMap 5.10, that can assist you in this. That makes it easier to
compare your notes/recollections to predictions, determine if what you
saw is a known object, and if element sets are accurate, or need to
be renewed.

Don't give up -- stay at it !

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