[amsat-bb] Re: NASA predix program

Nigel Gunn G8IFF/W8IFF nigel at ngunn.net
Wed Mar 11 17:08:42 PDT 2009

Thanks Alan.
I use either Orbitron or InstantTrack.
I had always wondered what the range circles over Russia were.
Does NASA have an official write up on the 'net.
Do we know the object numbers for the TDRS birds? My keps suggest there are 9 TDRS birds up there.

Alan Sieg WB5RMG wrote:

> There are several different views you may see, but the main thing that
> we "see" is the background map. Several "free" programs now utilize the
> map made from composite satellite images that looks natural and cloud-free.
> A good example someone pointed out is the default image in Orbitron.
> What sets the NASA maps apart is that they also usually show the coverage
> area of the three primary TDRS relay satellites, and marks on the future
> ground tracks to indicate orbital sunrise and sunsets. As the shuttle
> (or ISS) moves about the orbit, those coverage circles help visualize the
> "TDRSS handovers" where communications will drop out for a minute or a few.
> You may also notice on the ISS map view, the range circles about the Russian
> ground stations. During de-orbit and re-entry the background goes black and
> you'll see blue range circles about the various US radar tracking sites.
> During Joint-Ops with both Shuttle and ISS, they show Lat/Lon/Alt stats
> in the upper corners of the display. Lots of things they can turn on/off.
> The other display (my personal favorite) provides a multi-view in 3D space.
> I've heard it refered to as 'Birds Eye View' or BEV. I've seen similar
> applications running on SGI computers, with a 3 pane window... the top one
> a side view parallel to the velocity vector, with gravity down. The lower
> panes showing 1) a view from above sighting down along gravity, and 2) a
> view from slightly above looking forward along the velocity vector. These
> views are fed by live telemetry data that will include the vehicles
> orientation respective to those vectors. I really like watching those
> during orientation adjustments. If you can watch before docking, you can
> see how the ISS is rotated around to place the docking port 'in back' so
> that the Shuttle's TPS is better protcted from any orbital debris. If you
> see this display before re-entry you can see how they turn tail-forward
> in preparation for the de-orbit burn... I really enjoy watching this stuff.
> Still tho, it is hard to beat the 3D view in InstantTrack, especially on
> one of those Molniya orbits like AO-13, whippin around perigee - whoosh !
>    Enjoy   /;^)
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Nigel A. Gunn. G8IFF   W8IFF (was KC8NHF)
1865 El Camino Drive, Xenia, OH 45385-1115, USA   937 825 5032
e-mail nigel at ngunn.net             www  http://www.ngunn.net
Member of  ARRL, GQRP #11396, QRPARCI #11644, SOC #548,  Flying Pig #385,
                   Dayton ARA #2128,  AMSAT-NA   LM-1691,  AMSAT-UK, MKARS,  ALC

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