[amsat-bb] Gold Standard for Keplerian Data

Mon Nov 24 14:27:26 UTC 2014

I thought what it meant was that the software would ignore passes that did
not reach a minimum elevation. For example, if I had entered 15 degrees of
elevation that the software would ignore any passes that had a maximum
elevation of 14 degrees but would show the full pass detail for any that
were from 15 degrees to 90 degrees.

I am not proficient enough to work those that have a very low maximum
elevation, so until I am I want to ignore those that are pretty low.

What I have learned through this thread is that if a pass is going to have
a maximum elevation of 45 degrees that the software will show the AOS when
the satellite reaches 15 degrees, ignoring everything on that pass from 0
to 14 degrees.

It totally makes sense now.

What I am ultimately doing is testing a spreadsheet that I use to load a
series of passes into a Google Calendar that I have set up for myself. This
is pretty handy because I then have the calendar settings to notify me 45
minutes and 10 minutes before the pass. I was testing it and noticed the
inconsistencies this weekend between the software on my computer and the
AMSAT website.

This isn't a huge issue, though, because I am able to do the filtering on
my own for whatever maximum elevation I want to use from within the
spreadsheet.

I appreciate the help on this from everyone.

Steve May, W5IEM

On Mon Nov 24 2014 at 9:13:50 AM Mark Lunday <mlunday at nc.rr.com> wrote:

> Steve, I am confused.
>
> What does "minimum elevation" setting imply?  I thought as you stated
> below...
>
> Mark Lunday, WD4ELG
> Greensboro, NC  FM06be
> wd4elg at arrl.net
> http://wd4elg.blogspot.com
>
> -----Original Message-----
> From: amsat-bb-bounces at amsat.org [mailto:amsat-bb-bounces at amsat.org] On
> Behalf Of Steve May
> Sent: Monday, November 24, 2014 6:52 AM
> To: AMSAT-BB at amsat.org
> Subject: Re: [amsat-bb] Gold Standard for Keplerian Data
>
> 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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> > > > are solely those of the author, and do not reflect the official
> > > > views of
> > > AMSAT-NA.
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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!
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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
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>