[amsat-bb] Gold Standard for Keplerian Data

[Steve May]

Thank you very much guys. That was totally the reason for the issue.

I took the "minimum elevation" to mean that it would filter out all of the
passes in which the satellite never reaches x-degrees. Meaning that if it
didn't reach x-degrees from my location it would not display it, but for
those that did it would display the information for the full pass.

I did not realize that it would show the AOS for when the satellite reaches
x-degrees.

I checked against 2 satellites and it appears to have solved the problem.

Thank you again for your assistance on this.

Steve May, W5IEM



On Mon Nov 24 2014 at 5:19:33 AM David G0MRF <g0mrf at aol.com> wrote:

> Does this mean you are telling the PC to ignore all passes until they
> reach 15 degrees ?    - That's about 5 minutes.
>
> Prob best to take control back from the PC and set any limits at the
> horizon.
>
> Also, is this a 'real issue' with tracking, or just a problem with the
> computer giving different AOS times? It may be worth checking the time of
> closest approach which will avoid all of the AOS / LOS limits.
>
> Thanks
>
> David
>
> The time seems to be incorrect for all of the satellites I am trying to
> predict. Since I am only concerned with AO-7, FO-29, AO-73, and SO-50 they
> are the only ones I a running a prediction for, and since I am pretty new a
> this I am trying to use a 15-degree minimum elevation.
>
>
>
>
> -----Original Message-----
> From: Steve May <steve.w5iem at gmail.com>
> To: AMSAT-BB <AMSAT-BB at amsat.org>
> Sent: Mon, 24 Nov 2014 4:58
> Subject: Re: [amsat-bb] Gold Standard for Keplerian Data
>
>  I appreciate the suggestions. After a long day at work I have sat down this
> evening to look at the system, but I am still stumped.
>
> I am using a Windows 8.1 system, and the clock appears to be synchronized
> correctly. I am letting Windows set it automatically, and when I look at my
> cell phone the two display the same time and the minutes change
> simultaneously.
>
> The Keps seem to be updated correctly, and it shows that they are looking
> at the file that was updated earlier today. I looked in the directory and
> the updated nasa.all file is there.
>
> The time seems to be incorrect for all of the satellites I am trying to
> predict. Since I am only concerned with AO-7, FO-29, AO-73, and SO-50 they
> are the only ones I a running a prediction for, and since I am pretty new a
> this I am trying to use a 15-degree minimum elevation.
>
> I am generating a WinAos list, and it seems to be pretty much across the
> board hat the predictions in the WinAos software are about 5-6 minutes
> later than the predictions from the AMSAT website. Some of the predictions
> show a 1-degree difference in max elevation as well, although it isn't on
> every pass. These inconsistencies are probably based on rounding.
>
> It is showing this difference in time on every satellite in the predictions
> as well.
>
> I have checked and double-checked the Observer location on both predictions
> and I am using the correct location, EM78re. I have tried it on both
> predictions to enter the 6-digit grid square location as well as putting in
> the GPS coordinates manually and it doesn't seem to change anything.
>
> I am stumped by this. I assume it has to be something in my SatPC32 setup,
> and I will try it at work tomorrow on a different machine to see if the
> errors are the same.
>
> Any other suggestions?
>
> Steve, W5IEM
>
>
>
>
>
>
>
> On Sun Nov 23 2014 at 12:45:34 PM Erich Eichmann <erich.eichmann at t-online.de>
> wrote:
>
> > Steve,
> > I compared the results of the pass prediction from the AMSAT website for
> > the next 10 passes of FO-29 with the results of WinListen (that comes
> > with SatPC32) for my location (8.9 degrees east, 51.94 north). The
> > results are exactly the same (WinListen rounds the AOS/LOS times to the
> > closest full minute, however). It requires to enter and save your QTH
> > locator or longitude/latitude.   I used the latest file nasa.all as Keps
> > file.
> >
> > in most cases of different results between the AMSAT pass precition and
> > SatPC32  wrong longitude/latitude values in menu "Setup", "Observer" or
> > "Setup" of WinListen or  different  Keplerian data were the reason.
> >
> > What is your 6-digit QTH locator (or longitude west and latitude
> > north)?  What is the entry in SatPC32, menu "Observer" and in WinListen,
> > menu "Setup"?
> >   What Keps file do you use?  Download  the Keps file you use from
> > SatPC32 menu "Satellites", "Update Keps". When the download is
> > successful click "Quit" and then "OK". The path to the Keps files folder
> > can be seen in the foot line of menu "Satellites", the file date in the
> > bottom line of the SatPC32 main window and in the left list of the menu
> > you can choose the file. WinListen will use the same same path (foot
> > line in menu "Listen").
> >
> > 73, Erich, DK1TB
> >
> > Am 23.11.2014 17:04, schrieb Steve May:
> > > I have noticed that when I update the Keplerian Data for my location on
> > > SatPC32 and generate a list of passes they all seem to be about 5 minutes
> > > different than the predictions from the AMSAT website. This is for the
> > > earliest pass, and I am using the exact GPS coordinates for my location.
> > >
> > > So which do I rely on? Which predictions should I consider the "gold
> > > standard" for passes?
> > >
> > > Steve, W5IEM
> > > _______________________________________________
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> >
> _______________________________________________
> Sent via AMSAT-BB at amsat.org. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
> expressed
> are solely those of the author, and do not reflect the official views of
> AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>
>