[amsat-bb] Gold Standard for Keplerian Data

Mon Nov 24 15:05:44 UTC 2014

When I joined the ARMY to be a Calibrator of Test Equipment (TMDE or PMEL)
a CW2 looked at me and said:  "Private, the first thing you need to check
is yourself, there's a good chance there's nothing wrong with the
equipment".

That's where my tour around lots of wisdom started.  Mr. Bailey is gone
now, so I'm glad, much like Steve probably is, to have this group, for
things just like this.   (As a private you get to calibrate a whole lot of
Simpson 260's before moving on to scopes et al)

Or as a local ham, Ron says:

       Ron  KA4INM - Youvan's corollary:
                     Every action results in unwanted side effects.

Thanks Erich, I've learned something about your software.

Mike
W4UOO

On Monday, November 24, 2014, Steve May <steve.w5iem at gmail.com> wrote:

> 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 <javascript:;>>
> 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 <javascript:;>>
> > To: AMSAT-BB <AMSAT-BB at amsat.org <javascript:;>>
> > 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 <javascript:;>>
> > 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
> > > > _______________________________________________
> > > > Sent via AMSAT-BB at amsat.org <javascript:;>. 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
> > >
> > >
> > _______________________________________________
> > Sent via AMSAT-BB at amsat.org <javascript:;>. 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
> >
> >
> _______________________________________________
> Sent via AMSAT-BB at amsat.org <javascript:;>. 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
>

-- 
Thanks,
Mike Sprenger
(37.9167N  81.1244W is the Summit)