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CX2SA > SATDIG 18.08.11 15:12l 849 Lines 31344 Bytes #999 (0) @ WW
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Sent: 110818/1411Z @:CX2SA.LAV.URY.SA #:22589 [Minas] FBB7.00e $:AMSATBB6473
From: CX2SA@CX2SA.LAV.URY.SA
To : SATDIG@WW
Today's Topics:
1. Re: Turn off AGC when receiving BPSK-1000 (N0JY)
2. Us Vi (newsradio6@xxxxx.xxxx
3. Re: ARISSat-1 telemetry top submitters (Colin Hurst)
4. Re: Us Vi (Michael Schulz)
5. Re: Turn off AGC when receiving BPSK-1000 (Phil Karn)
6. South Texas Grid-peditions & LotW (Clayton W5PFG)
7. Re: ARISSat clock and TLM records (Douglas Quagliana)
8. Re: ARISSat-1 telemetry top submitters (Douglas Quagliana)
9. FUNcube Dongle SDR Available from ML&S (Trevor .)
10. Re: ISS School QSO
(Ransom, Kenneth G. (JSC-OC)[BARRIOS TECHNOLOGY])
11. Re: Turn off AGC when receiving BPSK-1000 (Trevor .)
12. Re: ARISSat clock and TLM records (Scott Richardson)
13. Re: Turn off AGC when receiving BPSK-1000 (Bob Bruninga)
14. ARISSat telemetry and Doppler tuning (Ronald G. Parsons)
15. Re: ARISSat telemetry and Doppler tuning (Alan P. Biddle)
16. Re: Turn off AGC when receiving BPSK-1000 (Andrew Glasbrenner)
----------------------------------------------------------------------
Message: 1
Date: Wed, 17 Aug 2011 20:47:04 -0500
From: N0JY <n0jy@xxxxxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: Turn off AGC when receiving BPSK-1000
Message-ID: <4E4C6F18.9020002@xxxxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
I have no option to turn off AGC with the FT-736R. I had been running
on the Medium setting (my default) and have switched to Slow now. I'm
not sure to say because it's rather subjective just watching, but I
think it has slightly improved capture especially at AOS and LOS as well
as when I have de-sensing due to my other VHF stations so rudely
beaconing their APRS and WL2K info without regard to the science going
on! ;-)
Jerry
N0JY
On 8/17/2011 6:24 PM, Alan Cresswell wrote:
> Hi Mark, Phil,
>
> That's interesting. I have collected all my passes on the TS2000 with the
> AGC on and set to the longest setting. This is mainly because I often
> record the signal level every 0.5 seconds during a pass which requires the
> AGC to be on and the longest setting irons out any short fades. I will turn
> the AGC off and look at the statistics over a few passes but given that with
> the AGC on I get almost all the available frames I don't expect to see much
> difference. It will be interesting to see.
>
> 73
> Alan
> ZL2BX
>
__________ Information from ESET NOD32 Antivirus, version of virus signature
database 6386 (20110817) __________
The message was checked by ESET NOD32 Antivirus.
http://www.eset.com
------------------------------
Message: 2
Date: Thu, 18 Aug 2011 01:56:22 +0000
From: newsradio6@xxxxx.xxx
To: "Amsat bb" <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Us Vi
Message-ID:
<1182931318-1313632583-cardhu_decombobulator_blackberry.rim.net-217025155-@xxx
.xx.xxxxx.xxxxxxxxxx>
Content-Type: text/plain; charset="Windows-1252"
Hi all..a last minute work trip has placed me in St Thomas, us virgin
islands for the next 2 days. No arrow but I have the handheld and was on the
2pm pass of ao27. Will try to be on some of the high angle passes of 27,
so50 and echo time permitting. Anyone know the grid sqr here?
John
WP2/VA3BL
Sent wirelessly from my BlackBerry device on the Bell network.
Envoy? sans fil par mon terminal mobile BlackBerry sur le r?seau de Bell.
------------------------------
Message: 3
Date: Thu, 18 Aug 2011 11:27:17 +0930
From: "Colin Hurst" <cjhurst@xxxxxxx.xxx.xx>
To: "'Alan Cresswell'" <alancresswell@xxxx.xx.xx>, "'Ben Bishop'"
<leorex@xxxxx.xxx>, "'AMSAT'" <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: ARISSat-1 telemetry top submitters
Message-ID: <005b01cc5d4a$28946a40$79bd3ec0$@xxx.xx>
Content-Type: text/plain; charset="utf-8"
Alan,
I noted that yesterday as well.
73
Colin.
-----Original Message-----
From: Alan Cresswell [mailto:alancresswell@xxxx.xx.xxx
Sent: Thursday, 18 August 2011 11:16
To: 'Colin Hurst'; 'Ben Bishop'; 'AMSAT'
Subject: RE: [amsat-bb] Re: ARISSat-1 telemetry top submitters
Hi Colin,
Yes, the other interesting thing is that recently ARISsat has been coming
out of eclipse not too long before the start of my morning passes. On those
occasions I have received anything up to 19 consecutive data frames (or
about 3 minutes) before I receive the first Kursk frame.
73
Alan
ZL2BX
-----Original Message-----
From: Colin Hurst [mailto:cjhurst@xxxxxxx.xxx.xxx
Sent: Thursday, 18 August 2011 01:21
To: 'Alan Cresswell'; 'Ben Bishop'; 'AMSAT'
Subject: RE: [amsat-bb] Re: ARISSat-1 telemetry top submitters
Alan,
The last KURSK segment I received were 741858 on the 12th August.
My educated guess is that because ARISSAT1 is resetting during every eclipse
the KURSK experiment is not able to obtain the MET and use it as a file name.
Hence it is defaulting to 944.
73
Colin VK5HI
-----Original Message-----
From: amsat-bb-bounces@xxxxx.xxx [mailto:amsat-bb-bounces@xxxxx.xxxx On
Behalf Of Alan Cresswell
Sent: Thursday, 18 August 2011 05:49
To: 'Ben Bishop'; 'AMSAT'
Subject: [amsat-bb] Re: ARISSat-1 telemetry top submitters
Hi all,
According to my logs the last Kursk frame I received on the 0405UT pass on
12 August was 720206. The first Kursk frame on the 12 August 2035UT pass
was 944. The interesting thing was that it apparently treated this as a
valid frame. i.e it accumulated and combined all five parts. All Kursk
frames from that point onward have been treated as "exists" and ignored.
2011/08/12-20:36:44 Received Kursk frame 5 with MET=944 len=48. Do we have
<C:\ARISSatTLM\Kursk\KURSK-944.5>?
2011/08/12-20:36:44 No. Saving to <C:\ARISSatTLM\Kursk\KURSK-944.5>.
2011/08/12-20:36:44 Checking for all five parts.
2011/08/12-20:36:44 <C:\ARISSatTLM\Kursk\KURSK-944.1>: OK.
2011/08/12-20:36:44 <C:\ARISSatTLM\Kursk\KURSK-944.2>: OK.
2011/08/12-20:36:44 <C:\ARISSatTLM\Kursk\KURSK-944.3>: OK.
2011/08/12-20:36:44 <C:\ARISSatTLM\Kursk\KURSK-944.4>: OK.
2011/08/12-20:36:44 <C:\ARISSatTLM\Kursk\KURSK-944.5>: OK.
2011/08/12-20:36:44 Combining KURSK parts into
<C:\ARISSatTLM\Kursk\KURSK-944.EXP>.
2011/08/12-20:36:44 Done combining.
2011/08/12-20:36:44 Forwarding from ZL2BX to telemetry.arissattlm.org frame
type E
2011/08/12-20:36:50 Received telemetry frame with MET=1589 Len=371
2011/08/12-20:36:50 Forwarding from ZL2BX to telemetry.arissattlm.org frame
type T
2011/08/12-20:36:58 Received Kursk frame 1 with MET=944 len=516. Do we have
<C:\\ARISSatTLM\Kursk\KURSK-944.1>?
2011/08/12-20:36:58 Yes. <C:\ARISSatTLM\Kursk\KURSK-944.1> exists.
2011/08/12-20:36:58 Forwarding from ZL2BX to telemetry.arissattlm.org frame
type E
73
Alan
ZL2BX
-----Original Message-----
From: amsat-bb-bounces@xxxxx.xxx [mailto:amsat-bb-bounces@xxxxx.xxxx On
Behalf Of Ben Bishop
Sent: Wednesday, 17 August 2011 14:36
To: AMSAT
Cc: n0jy@xxxxxxx.xxx
Subject: [amsat-bb] Re:ARISSat-1 ??? telemetry top submitters
G'day Jerry,
I don't think there's anything wrong with your ARISSatTLM, as I've
only been getting KURSK-944s since the 13th.
My last 'proper good' experiment frame was:
2011/08/11-08:12:48 Received Kursk frame 2 with MET=650105 len=516.
Satellite MET around then was:
2011/08/11-08:12:54 Received telemetry frame with MET=653412 Len=371
I missed the 12th, and on the 13th the telemetry and experiment MET had reset:
2011/08/13-04:34:16 Received telemetry frame with MET=2514 Len=371
.....
2011/08/13-04:34:24 Received Kursk frame 3 with MET=944 len=516. Do we
have <C:\Users\Ben\Desktop\ARISSatTLM\Kursk\KURSK-944.3>?
2011/08/13-04:34:24 No. Saving to
<C:\Users\Ben\Desktop\ARISSatTLM\Kursk\KURSK-944.3>.
And from that point on, I have only received KURSK-944 frames (which
are still auto-forwarding).
2011/08/17-05:30:04 Received Kursk frame 5 with MET=944 len=48. Do we
have <C:\Users\Ben\Desktop\ARISSatTLM\Kursk\KURSK-944.5>?
2011/08/17-05:30:04 Yes.
<C:\Users\Ben\Desktop\ARISSatTLM\Kursk\KURSK-944.5> exists.
73,
Ben VK2FBRB
On Wed, Aug 17, 2011 at 11:08 PM, <n0jy@xxxxxxx.xxx> wrote:
> A question for all, for a few days now my ARISSatTLM has been reporting
> the Kursk as being (I believe, I'm not at home to check right now)
> something like Kursk-944.x or perhaps it was Kursk-444.x (some real low
> perhaps hung up on that and needs a restart? Anyone else, what are the
> latest Kursk frames that you are seeing?
_______________________________________________
Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
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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Checked by AVG - www.avg.com
Version: 10.0.1392 / Virus Database: 1520/3840 - Release Date: 08/17/11
_______________________________________________
Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
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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Version: 10.0.1392 / Virus Database: 1520/3841 - Release Date: 08/17/11
------------------------------
Message: 4
Date: Wed, 17 Aug 2011 21:09:39 -0500
From: Michael Schulz <mschulz@xxxxxxxxxxxxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: Us Vi
Message-ID: <4E4C7463.2020106@xxxxxxxxxxxxxx.xxx>
Content-Type: text/plain; charset=windows-1252; format=flowed
Well, first of all, your job sucks HI HI ..
The grid square is FK78. Hope to hear you on the 10:18 UTC pass of AO-51.
73 Mike K5TRI
On 8/17/2011 8:56 PM, newsradio6@xxxxx.xxx wrote:
> Hi all..a last minute work trip has placed me in St Thomas, us virgin
islands for the next 2 days. No arrow but I have the handheld and was on the
2pm pass of ao27. Will try to be on some of the high angle passes of 27,
so50 and echo time permitting. Anyone know the grid sqr here?
> John
> WP2/VA3BL
>
> Sent wirelessly from my BlackBerry device on the Bell network.
> Envoy? sans fil par mon terminal mobile BlackBerry sur le r?seau de Bell.
>
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 5
Date: Wed, 17 Aug 2011 19:13:33 -0700
From: Phil Karn <karn@xxxxxxxx.xxx>
To: Alan Cresswell <alancresswell@xxxx.xx.xx>
Cc: 'Amsat - BBs' <amsat-bb@xxxxx.xxx>, "'Mark L. Hammond'"
<marklhammond@xxxxx.xxx>
Subject: [amsat-bb] Re: Turn off AGC when receiving BPSK-1000
Message-ID: <4E4C754D.1020804@xxxxxxxx.xxx>
Content-Type: text/plain; charset=UTF-8
On 8/17/11 4:24 PM, Alan Cresswell wrote:
> That's interesting. I have collected all my passes on the TS2000 with the
> AGC on and set to the longest setting. This is mainly because I often
> record the signal level every 0.5 seconds during a pass which requires the
> AGC to be on and the longest setting irons out any short fades.
The main thing is that the gain remain constant, or nearly so, during
each fade so that the random series of 0's and 1's produced during the
fade on thermal noise is mostly seen as 'weak' 0's and 'weak' 1's.
Increasing the gain during a fade makes those random bits seem stronger
and more certain when they're still just random bits. That can make it
harder for the Viterbi decoder to correct them as errors.
A Viterbi decoder works much like a network routing algorithm that looks
for the cheapest path to a destination. It finds the best path through a
'trellis', a pattern of links corresponding to all possible state
transitions in the convolutional encoder that produced the transmitted
signal. Out of every possible path the decoder finds the one that most
closely matches the received sequence and declares it as the one that
was most likely sent. It can still be wrong, and when it does it usually
emits a burst of several dozen errors until the decoder gets back on the
right path. In BPSK-1000, this error burst causes the HDLC decoder to
abort the current frame or discard it with a CRC error.
The Viterbi decoder tallies up the 'cost' of each link in a path to find
its total 'path cost'. If a particular link assumes that a '0' was sent,
then receiving a strong '0' is the best possible match so that results
in the lowest possible cost for that link. A weak '0' gives a greater
cost, a weak '1' an even greater cost, and a strong '1' gives the
highest possible cost.
Even if one link in a path has a high cost, the complete path will still
be chosen as the winner if all the other paths are worse. When this
happens, typically all the other links in the path will closely match
the received sequence.
So you really want to avoid classifying bits as 'strong' when you know
the signal is gone and the bits can't possibly be right. That means not
boosting the gain (and the noise level) during a fade. The noise level
should be kept constant.
-Phil
------------------------------
Message: 6
Date: Wed, 17 Aug 2011 22:17:39 -0500
From: Clayton W5PFG <kayakfishtx@xxxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] South Texas Grid-peditions & LotW
Message-ID:
<CAPovOwc8PdV86fyMdXCSmWGiQ4y2dvqqneVC7=8nH6A1LM12ug@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
I've attempted to reconcile recent Texas grid-peditions in Logbook of the
World. This includes my operations in EM01, EM02, EM03, EM04, EM10, EM11,
EM12, EM22, DM94, DM95, DM96, EL29, and EL39. If you are waiting on a QSL
via LotW and you don't see it, send me the QSO data and I will check to see
that I uploaded our contact from the right location in TQSL.
August 22-24 I am going to be in the "neighborhood" of EL07, DL98, DL99, and
DM90 in Southwest Texas. My exact operating times are not ironed out but
my intentions are to make passes of AO-27, AO-51, and potentially SO-50.
As this is a work trip and satellite operations are a secondary task, I
cannot confirm the dates and times where I'll make passes just yet.
73
Clayton
W5PFG
------------------------------
Message: 7
Date: Wed, 17 Aug 2011 22:26:39 -0500
From: Douglas Quagliana <dquagliana@xxx.xxx>
To: Richard Ferryman <g4bbh@xxxxxxxxxx.xxx>
Cc: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: ARISSat clock and TLM records
Message-ID: <4E4C866F.60900@xxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Hi Richard,
Don't worry. All of the telemetry data sent to telemetry.arissattlm.org
is timestamped with the UTC date and time when the receiving station
received the telemetry. All received telemetry is saved to a .CSV file
(one CSV file per day) with one line per telemetry frame. Each
telemetry frame/line in the .CSV file is also timestamped with the UTC
date and time when the receiving station received the telemetry.
If you received any telemetry, please email your .CSV files to telemetry
(at) arissattlm.org
73,
Douglas KA2UPW/5
Richard Ferryman wrote:
> Now that the ARISSat clock seems to be resetting on a regular basis I am
wondering how this will affect the TLM and Kursk data which I am capturing
and uploading. It seems to me that the only way of collating the data is by
the time of upload to telemetry.arissattlm.org
> Dick G4BBH
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>
>
------------------------------
Message: 8
Date: Wed, 17 Aug 2011 22:44:18 -0500
From: Douglas Quagliana <dquagliana@xxx.xxx>
To: Mike Rupprecht <mail@xxxxxxxxxxxxxx.xx>
Cc: 'Roland Zurmely' <py4zbz@xxxxx.xxx>, 'AMSAT' <amsat-bb@xxxxx.xxx>,
n0jy@xxxxxxx.xxx
Subject: [amsat-bb] Re: ARISSat-1 telemetry top submitters
Message-ID: <4E4C8A92.5080301@xxx.xxx>
Content-Type: text/plain; charset=UTF-8; format=flowed
>All these data are based on the STP telemetry files from the AMSAT-FTP
server
>(Kursk / Spacecraft). Every telemetry frame exist only once.
>If 10 stations listen to ARISSat and every station is forwarding the
telemetry
>to the server - only one packet wins.
Actually, the telemetry on the AMSAT-FTP server represents all of the
frames that the ARISSatTLM telemetry server received from all of the
ARISSatTLM users. Duplicate telemetry frames have not been
removed. This is all of the raw data.
Douglas KA2UPW/5
------------------------------
Message: 9
Date: Thu, 18 Aug 2011 11:35:23 +0100 (BST)
From: "Trevor ." <m5aka@xxxxx.xx.xx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] FUNcube Dongle SDR Available from ML&S
Message-ID:
<1313663723.81126.YahooMailClassic@xxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=utf-8
The AMSAT-UK FUNcube Dongle VHF/UHF Software Defined Radio can now be
purchased online from the Amateur Radio retailer Martin Lynch & Sons, see
http://tinyurl.com/MartinLynchFCD
A reminder that a link to view videos of the presentations given at the
AMSAT-UK International Space Colloquium can be found at
http://www.uk.amsat.org/
AMSAT-UK publishes a color A4 newsletter, OSCAR News, that is full of
Amateur Satellite information. The Spring OSCAR News can be seen
athttp://www.uk.amsat.org/on_193_final.pdf
Join AMSAT-UK online at http://tinyurl.com/JoinAMSAT-UK/
73 Trevor M5AKA
------------------------------
Message: 10
Date: Thu, 18 Aug 2011 05:58:02 -0500
From: "Ransom, Kenneth G. (JSC-OC)[BARRIOS TECHNOLOGY]"
<kenneth.g.ransom@xxxx.xxx>
To: James Luhn <luhn@xx.xxx>, "amsat-bb@xxxxx.xxxx
<amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: ISS School QSO
Message-ID:
<CBB2346C58D9B14983E5AEFE4B3458868EF98745F0@xxxxxxxxx.xxx.xxxx.xxx>
Content-Type: text/plain; charset="us-ascii"
James,
No ham event scheduled for Aug. 18. There was one on Aug 16 over Japan and
the next one is Aug 25 with Germany via LU8YY in Argentina.
Are you referring to the following educational video downlink posting?
http://www.amsat.org/amsat/archive/amsat-bb/10day/msg89701.html
Kenneth - N5VHO
-----Original Message-----
From: amsat-bb-bounces@xxxxx.xxx [mailto:amsat-bb-bounces@xxxxx.xxxx On
Behalf Of James Luhn
Sent: Wednesday, August 17, 2011 6:58 PM
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] ISS School QSO
I am portable in Alabama and do not have access to my past e-mail. A post a
day or so ago had information about a school that had a scheduled QSO with
the ISS on August 18. I am at a camp in Alabama and would love to at least
monitor the conversation coming from the ISS. Would someone repost the info
or contact me directly with a copy of the post.
73,
James
W5AOO
luhn@xx.xxx
_______________________________________________
Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
Not an AMSAT-NA member? Join now to support the amateur satellite program!
Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 11
Date: Thu, 18 Aug 2011 13:09:29 +0100 (BST)
From: "Trevor ." <m5aka@xxxxx.xx.xx>
To: Amsat - BBs <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: Turn off AGC when receiving BPSK-1000
Message-ID:
<1313669369.88302.YahooMailClassic@xxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=utf-8
--- On Thu, 18/8/11, Phil Karn <karn@xxxxxxxx.xxx> wrote:
> For attitude control, I think control moment gyros are the
> way to go. (They're somewhat different from momentum wheels
> in that they operate at constant speed.) This is largely a
> mechanical problem: designing flywheels and motors that are small,
> lightweight, can store a lot of angular momentum, draw minimal power,
> and be precisely moved around to control the direction and magnitude
> of the overall spacecraft angular momentum vector. We'd still need
> magnetorquing coils to dump excess momentum, but the cm gyros would
> provide quick and accurate control of spacecraft attitude.
There is discussion of the means of stabilsation and the use of 2.4 and 5
GHz on a future satellite in the Positioning and Experiments sections of the
Forum at http://tinyurl.com/RadioSkaf
73 Trevor M5AKA
------------------------------
Message: 12
Date: Thu, 18 Aug 2011 08:12:38 -0400
From: Scott Richardson <scott.xot@xxxxx.xxx>
To: Douglas Quagliana <dquagliana@xxx.xxx>
Cc: amsat-bb <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: ARISSat clock and TLM records
Message-ID:
<CABiJrLjQnsXqvkKt=5=wB-G0QLybEB9O-Qd6ZZheZ5kxSr453w@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
Last night I captured my first telemetry frames by holding a digital
recorder in front of the speaker on my TH-F6A, then playing the audio back
through my soundcard an hour or so later. I was pleasantly surprised to get
a few good frames and impressed with how smoothly the software worked.
Unfortunately, the timestamps in the CSV file are the playback times, not
the capture times. I realized this after auto-submitting the telemetry.
Would this "bad data" have been filtered somehow upon submission? When I use
this method, should I manually edit the timestamps and submit the CSV via
email while turning off autosubmit?
Tnx and 73, Scott N1AIA
On Wed, Aug 17, 2011 at 11:26 PM, Douglas Quagliana <dquagliana@xxx.xxx>wrote:
> Hi Richard,
>
> Don't worry. All of the telemetry data sent to telemetry.arissattlm.orgis
timestamped with the UTC date and time when the receiving station
> received the telemetry. All received telemetry is saved to a .CSV file (one
> CSV file per day) with one line per telemetry frame. Each telemetry
> frame/line in the .CSV file is also timestamped with the UTC date and time
> when the receiving station received the telemetry.
>
> If you received any telemetry, please email your .CSV files to telemetry
> (at) arissattlm.org
>
> 73,
> Douglas KA2UPW/5
>
>
>
>
> Richard Ferryman wrote:
>
>> Now that the ARISSat clock seems to be resetting on a regular basis I am
>> wondering how this will affect the TLM and Kursk data which I am capturing
>> and uploading. It seems to me that the only way of collating the data is
by
>> the time of upload to telemetry.arissattlm.org
>> Dick G4BBH
>> ______________________________**_________________
>> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
>> Not an AMSAT-NA member? Join now to support the amateur satellite program!
>> Subscription settings:
http://amsat.org/mailman/**listinfo/amsat-bb<http://amsat.org/mailman/listinfo
/amsat-bb>
>>
>>
>>
>
> ______________________________**_________________
> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings:
http://amsat.org/mailman/**listinfo/amsat-bb<http://amsat.org/mailman/listinfo
/amsat-bb>
>
------------------------------
Message: 13
Date: Thu, 18 Aug 2011 08:47:44 -0400
From: "Bob Bruninga" <bruninga@xxxx.xxx>
To: "'Amsat - BBs'" <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: Turn off AGC when receiving BPSK-1000
Message-ID: <023b01cc5da5$06375ba0$12a612e0$@xxx>
Content-Type: text/plain; charset="us-ascii"
[Using attitude control]...
> We could mount microwave antennas on a nadir-facing
> surface and provide consistent, predictable, strong,
> wideband signals to ground stations during a pass.
The problem with LEO satellites is that a nadir facing antenna does give
great gain directly overhead ground stations, but only for about the center
2 minutes of only the one direct overhead pass a day. The problem with
facing antennas "down" on a LEO satellite is that 90% of the users are not
"under it", but to the side of it.
For example, lets say that we put relatively high gain antennas facing down
giving about a 45 degree antenna pattern (say around 10 dB). Now looking at
the total time that ARISSat is above 45 degrees, turns out to be about 3
minutes a day or less than 10% of all the time it is in view to any one
ground station.
But as you say, it is a great advantage if the objective is to provide a 2
minute comm. window to anyone on the planet once a day, then such a design
does give as much as 16 dB or so advantage over an omni antenna on a
satellite.
Anyway, just a thought.
Bob, WB4APR
------------------------------
Message: 14
Date: Thu, 18 Aug 2011 08:35:25 -0500
From: "Ronald G. Parsons" <w5rkn@xxxxx.xxx>
To: "AMSAT-BB" <AMSAT-BB@xxxxx.xxx>
Subject: [amsat-bb] ARISSat telemetry and Doppler tuning
Message-ID: <FA3D30E83B4F49BB94F5F6448C8C2815@xxxxxxxxx>
Content-Type: text/plain; charset="UTF-8"
Last evening, after having several days experience capturing ARISSat
telemetry, I sat at my radio and watched carefully how SatPC32 and
ARISSatTLM played together. I had settled on a tuning correction value of
?540 HZ to get the CW signal to center around the CW tuning point as the
Doppler correction was handled by SatPC32.
The approach of the satellite seemed normal. but as the satellite passed by,
I noticed the CW signal average ?position? to be creeping upward, needing a
reduction of the tuning correction by about 40 Hz to ?500 Hz. This lasted
for a couple minutes and then the CW signal started creeping down and I had
to go back to my ?540 Hz value.
The first explanation I could think of is that the Doppler correction
computed by SatPC32 from my position and the keps was in error. But of
course, it could have been a change in my radio (unlikely as it had been on
for hours) or a change in the frequency of the CW signal from the satellite.
I?ll keep watching this and wonder if others have noticed something similar.
Ron W5RKN
------------------------------
Message: 15
Date: Thu, 18 Aug 2011 08:59:58 -0500
From: "Alan P. Biddle" <APBIDDLE@xxxxxx.xxx>
To: "'Ronald G. Parsons'" <w5rkn@xxxxx.xxx>, "'AMSAT-BB'"
<AMSAT-BB@xxxxx.xxx>
Subject: [amsat-bb] Re: ARISSat telemetry and Doppler tuning
Message-ID: <C50B28FCF5BE4BE4AA65DE45307B3026@xxxxxx>
Content-Type: text/plain; charset="us-ascii"
Ron,
That behavior is common around TCA, Time of Closest Approach. At that time
everything is changing rapidly, and slight errors in QTH position, system
clock, and Keps can be magnified. I have seen a few hundred Hz shift at
that time with new satellites whose Keps have not fully converged. The same
if the system clock is off a bit. As you probably know, the basic Windows
internet time calibration facility can be tweaked, but it is better to
replace it with one such as Meinberg. Finally, always have the latest Keps.
Updating with SATPC32 is easy and only takes a few seconds.
It is unlikely to be a factor on 2 meters, with a fast computer, but you can
try increasing the update calculations in SATPC32. Look on the CAT page.
You will see tick boxes for 1X, 5X and 10X. Try 5X and see if it makes any
difference. Note that this setting is not sticky.
Actually, your results show you have just about everything nailed.
73s,
Alan
WA4SCA
-----Original Message-----
From: amsat-bb-bounces@xxxxx.xxx [mailto:amsat-bb-bounces@xxxxx.xxxx On
Behalf Of Ronald G. Parsons
Sent: Thursday, August 18, 2011 8:35 AM
To: AMSAT-BB
Subject: [amsat-bb] ARISSat telemetry and Doppler tuning
Last evening, after having several days experience capturing ARISSat
telemetry, I sat at my radio and watched carefully how SatPC32 and
ARISSatTLM played together. I had settled on a tuning correction value of
-540 HZ to get the CW signal to center around the CW tuning point as the
Doppler correction was handled by SatPC32.
The approach of the satellite seemed normal. but as the satellite passed by,
I noticed the CW signal average "position" to be creeping upward, needing a
reduction of the tuning correction by about 40 Hz to -500 Hz. This lasted
for a couple minutes and then the CW signal started creeping down and I had
to go back to my -540 Hz value.
The first explanation I could think of is that the Doppler correction
computed by SatPC32 from my position and the keps was in error. But of
course, it could have been a change in my radio (unlikely as it had been on
for hours) or a change in the frequency of the CW signal from the satellite.
I'll keep watching this and wonder if others have noticed something similar.
Ron W5RKN
_______________________________________________
Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
Not an AMSAT-NA member? Join now to support the amateur satellite program!
Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 16
Date: Thu, 18 Aug 2011 09:08:06 -0500
From: Andrew Glasbrenner <glasbrenner@xxxxxxxxxx.xxx>
To: Bob Bruninga <bruninga@xxxx.xxx>
Cc: Amsat - BBs <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: Turn off AGC when receiving BPSK-1000
Message-ID: <461FBCDE-C2B3-4035-9BFC-3298B14A944C@xxxxxxxxxx.xxx>
Content-Type: text/plain; charset=us-ascii
>From what I have read that is published, the DOD Colony II 3u cubesats are
3 axis controlled and pointable to within a degree or something close to
that. As Bob pointed out this isn't a big help for antenna pointing for
multiuser LEO sats, but when you read the power production the Colony II
sats have, you'll see the application in a HEO orbit. I believe a 3u in HEO
with this ability would be an affordable, usuable satellite for AMSAT to
launch if we could duplicate the Colony sats abilities.
73, Drew KO4MA/p at the corner of No and Where, Oklahoma
Sent from my iPhone
On Aug 18, 2011, at 7:47 AM, "Bob Bruninga" <bruninga@xxxx.xxx> wrote:
> [Using attitude control]...
>
>> We could mount microwave antennas on a nadir-facing
>> surface and provide consistent, predictable, strong,
>> wideband signals to ground stations during a pass.
>
> The problem with LEO satellites is that a nadir facing antenna does give
> great gain directly overhead ground stations, but only for about the center
> 2 minutes of only the one direct overhead pass a day. The problem with
> facing antennas "down" on a LEO satellite is that 90% of the users are not
> "under it", but to the side of it.
>
> For example, lets say that we put relatively high gain antennas facing down
> giving about a 45 degree antenna pattern (say around 10 dB). Now looking at
> the total time that ARISSat is above 45 degrees, turns out to be about 3
> minutes a day or less than 10% of all the time it is in view to any one
> ground station.
>
> But as you say, it is a great advantage if the objective is to provide a 2
> minute comm. window to anyone on the planet once a day, then such a design
> does give as much as 16 dB or so advantage over an omni antenna on a
> satellite.
>
> Anyway, just a thought.
> Bob, WB4APR
>
>
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
> 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@xxxxx.xxx. Opinions expressed are those of the author.
Not an AMSAT member? Join now to support the amateur satellite program!
http://amsat.org/mailman/listinfo/amsat-bb
End of AMSAT-BB Digest, Vol 6, Issue 473
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