[amsat-bb] THANKS Re: Where did the TLEs go for BY70-1?

Mac A. Cody maccody at att.net
Mon Jan 30 05:43:04 UTC 2017


I worked BY70-1 during the 0439 UTC pass this evening using the TLEs
provided through AMSAT.org.  I had a successful QSO with W5ACM in
EL29 (I'm in EM12).  It became obvious, though, that BY70-1 arrived
sooner than the TLEs indicated.  It was very difficult to maintain
proper aiming and Doppler shift correction enable proper communication
with BY70-1 during the times around TCA.

For those interested,  I sent the email below to Dr. Kelso at
Celestrak.com.  Hopefully, something will be done shortly.

73,

Mac / AE5PH

Dr. Kelso,

First, let me express my thanks for your excellent web site and TLE
data service.  I have used it numerous times over the years to learn
more about satellite dynamics and, in recent months, to obtain
predictions for amateur satellites for communications.

There has been a lot of interest in the amateur satellite community
regarding the recently-launched Chinese cubesat BY70-1.  While it is
sad to know that it will reenter in a few weeks, ham radio operators
have been communicating through BY70-1 as much as possible.

Since BY70-1 has exited the listing of satellites launched in the
last 30 days, it has become difficult to load timely TLE data into
the commonly available amateur satellite tracking softwares.  I was
wondering if it would be possible to place the TLE data for BY70-1
into the Amateur Radio or CubeSats listing so that timely updates
become available again.  This would only be to be done for the short
term, as it is currently estimated that BY70-1 will reenter about
February 22, 2017.

Thanks for your consideration.

Regards,

Mac Cody / AE5PH


On 01/29/2017 07:21 AM, Alan wrote:
> A suggestion would be to contact Tim through his website, politely explain that BY70-1 is of interest
> to amateurs, and request that he include it in the amateur.txt list because you need frequent updates.
> In the past he has been very responsive.
>
> 73s,
>
> Alan
> WA4SCA
>
>
>
>
> <-----Original Message-----
> <From: AMSAT-BB [mailto:amsat-bb-bounces at amsat.org] On Behalf Of Todd Deckard
> <Sent: Sunday, January 29, 2017 6:48 AM
> <To: amsat-bb at amsat.org
> <Subject: [amsat-bb] THANKS Re: Where did the TLEs go for BY70-1?
> <
> <Greetings Mac,
> <
> <Thanks for this!
> <
> <The AMSAT ftp site isn't updated frequently enough for the deteriorating orbit and a single precision
> <PLAN13 implementation on the ATmega1280.
> <
> <As an example here's the CELESTRAK output:
> <
> <BY70-1
> <1 41909U 16083C   17029.24424671  .00506735  24288-5  70240-3 0  9991
> <2 41909  97.5768 109.7306 0160558 244.2616 114.2002 15.85900257  5044
> <
> <Here's the AMSAT record sampled from the same time.
> <
> <BY70-1
> <1 41909U 16083C   17026.84471594  .00329730  24344-5  49404-3 0  9999
> <2 41909  97.5781 107.0760 0167800 253.3870 105.1424 15.83446051  4663
> <
> <As expected, atmospheric drag has the largest effect on the semi-major axis, eccentricity, and
> argument
> <of perigee. Alas it won't be long now.  Still haven't gotten a confirmed QSO!
> <
> <Best
> <Todd
> <
> <
> <>Mac A. Cody maccody at att.net
> <>Sun Jan 29 02:43:52 UTC 2017
> <>Previous message: [amsat-bb] Where did the TLEs go for BY70-1?
> <>Next message: [amsat-bb] NJ7H-9
> <>Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]
> <>Todd,
> <
> <>Mark KK6OTJ told me that you can find the latest TLEs for BY70-1 by using
> <>the SATCAT search function at http://www.celestrak.com/satcat/search.asp
> <>Search using the name BY70-1.
> <>
> <>73,
> <>
> <>Mac / AE5PH
> <
> <
> <_______________________________________________
> <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://www.amsat.org/mailman/listinfo/amsat-bb
>
>
> _______________________________________________
> 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://www.amsat.org/mailman/listinfo/amsat-bb
>



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