Current Keps

[VK2FAK]

Hi all...

Was just about to update to the latest Keps...when I noticed a difference...

Which is right or are they both right....?


using VO-52 as the example..

Nasa 2 line 24th Nov.
VO-52
1 28650U 05017B 11328.69854330 .00002465 00000-0 31190-3 0 9575
2 28650 097.6242 004.5010 0026886 358.2563 001.8531 14.82440328354528

Current Keps on the Status Page..( I guess the Keps they do there online tracking with )
VO-52
1 28650U 05017B 11331.19594995 .00002022 00000-0 25694-3 0 9595
2 28650 97.6230 6.8810 0026597 350.2008 9.8709 14.82449141354890

John

[VK6ADF]

The second list of keps are the most recent. There is a slight time difference between them. I have not checked but most likely the difference would result in such a small difference in satellite location it does not matter.

The kep file is probably updated weekly whereas the live tracking possibly gets the data live and it changed slightly since the file was generated.

Sorry about all the probablies, possiblies, maybe's, most likelies etc etc. I am only guessing what is the most likely reason.

Are you downloading the files and manually updating the tracking program? Most programs can download and update the keps automatically or upon manual initiation from within the program. Thats the best way to update the keps.

One of the AMSAT webpages mentions this "We suggest updating the keps every 2 weeks, depending on the height of the satellite you're interesed in. Update every couple of weeks for low orbiting satellites, and every 4-5 weeks for high orbiting ones."

[VK2FAK]

Hi all..

Yes the software does update the data....but I am struggling to have confidence in it..

I wanted to have a visual look again...of the ISS last evening ( mainly because it was nice and cool outside..)...When I check the pass and saw nothing I assumed it was just not visible. but I changed data, from an automatically updated to my manual updated list and found the ISS was not due yet and saw it on time...so not overly trusting of the data provided.

I only have a few on watch so is easy enough to change manually....cut, copy and paste...is easy enough....hihi

John

[VK6ADF]

You can always check satellite location on the AMSAT pages to double check your data. Might have corrupted as you downloaded so a second update would not be a bad idea if you find a difference. Most programs update from the same sources so the original data is probably ok.

What program did you end up using? and where does the program download the data from?

I can't say I have ever experienced bad data before. The tracks from several tracking programs I have installed on my PC have always been very close to each other.

[VK2FAK]

Hi all...

As a beginning in LEO sat's I am just sticking with Orbitron at the moment.....one reason I started to question it was when I read elsewhere some people had problems with the standard source in that program...I had not noticed any problems until yesterday...so who knows...

I rather just be confident and not have to worry about....so takes a minute or so to update it manually so no real drama's.

John

[VK6ADF]

.....one reason I started to question it was when I read elsewhere some people had problems with the standard source in that program...

John

As long as you end up with the correct keps it does not really matter how you get them there. Just remember that the Orbitron program itself has not been updated since 2005. You might argue when a program reaches perfection why change it. I prefer others from more recent years.

I would suspect a program glitch of some type rather than the keplerian data, which is also used by other programs seemingly without problems.

I just updated the keps in my copy of Orbitron and ISS for example matches the program I mainly use, so when working as it is supposed to it is as good as any.

Have fun with the satellites..thats the main thing.