[amsat-bb] LongJiang and Doppler correction

Wed May 30 12:57:40 UTC 2018

Hello Mike.
I saw new files but I do not know where I should to put this file (which 
folder?).

Regards.

------ Original Message ------
From: "Mike Rupprecht" <mail at mike-rupprecht.de>
To: "'Dimitry Borzenko'" <dibor at iname.com>; "'AMSAT BB'" 
<amsat-bb at amsat.org>
Sent: 30.05.2018 14:56:51
Subject: AW: [amsat-bb] LongJiang and Doppler correction

>Hi Dimitry,
>
>TLE are useles in lunar orbit.
>
>You have to update the tracking file in all four decoders.
>
>https://github.com/bg2bhc/dslwp_doc/blob/master/program_tracking_dslwp-b_201
>80529.txt
>
>(or later files)
>
>73 Mike
>DK3WN
>
>-----Ursprüngliche Nachricht-----
>Von: AMSAT-BB [mailto:amsat-bb-bounces at amsat.org] Im Auftrag von 
>Dimitry
>Borzenko
>Gesendet: 30 May 2018 10:36
>An: AMSAT BB
>Betreff: Re: [amsat-bb] LongJiang and Doppler correction
>
>Hello.
>Have problem with running Live CD.
>Have made USB bootable diskONkey , system is runs.
>Mun Downlink Proxy is configured and Orbit TLE can be downloaded, but 
>ALL
>ports is NOT connected!
>RTL is running and freq. calibrated.
>Also while running Decoder got 4 terminals running and have some 
>message
>about "File is not find or EOF ....."
>
>What I did wrong?
>
>de 4z5cp.
>
>
>------ Original Message ------
>From: "Scott" <scott23192 at gmail.com>
>To: "AMSAT BB" <amsat-bb at amsat.org>
>Sent: 30.05.2018 2:30:33
>Subject: Re: [amsat-bb] LongJiang and Doppler correction
>
>>Hi Jean Marc.
>>
>>I have tried to follow the news of these lunar satellites.  While
>>several of the guys with DSN capability have received the S-Band
>>downlinks, I'm not aware of anyone hearing anything on 70cm past the
>>first day as the sats left Earth.
>>
>>In fact, even though I am listening every night for the 70cm telemetry
>>(using the team's GNU Radio flowgraphs), I have not heard any
>>confirmation that the 70cm transmitter is even on (telemetry -or- 
>>JT4).
>>
>>-Scott,  K4KDR
>>
>>
>>=======================================================
>>
>>-----Original Message----- From: Jean Marc Momple
>>Sent: Tuesday, May 29, 2018 12:37 PM
>>To: AMSAT BB
>>Subject: Re: [amsat-bb] LongJiang and Doppler correction
>>
>>Dear All,
>>
>>May be a stupid question for the experts, but genuine from me.
>>
>>Has anyone received any FT4G beacon signal from the Longiang Sats so
>>far?
>>
>>I have being trying to do so for the past week without success.
>>
>>73
>>
>>
>>Jean Marc (3B8DU)
>>
>>
>>
>>
>>>On May 26, 2018, at 8:54 PM, Nico Janssen <hamsat at xs4all.nl> wrote:
>>>
>>>
>>>In the coming days the doppler shift on the 70 cm downlink of
>>>LongJiang 2 will vary between +2000 and -2200 Hz (for my QTH).
>>>This can easily be calculated with GMAT using the script I published 
>>>a
>>>couple of hours ago (see my earlier post).
>>>
>>>73,
>>>Nico PA0DLO
>>>
>>>On 26-05-18 17:44, charlie at sucklingfamily.free-online.co.uk wrote:
>>>>Michael
>>>>
>>>>I think that there are three main components to the Doppler shift 
>>>>for
>>>>a satellite orbiting the moon.
>>>>
>>>>1.  Earth rotation moving the observer toward the moon at moonrise
>>>>(+ve
>>>>Doppler) and moonset (-ve).
>>>>
>>>>2.  Earth-moon distance variation (smaller than 1, and very slowly
>>>>changing in comparison).
>>>>
>>>>3.  Orbital velocity of the satellite itself.
>>>>
>>>>1 and 2 are easy to work out using EME software, eg WSJT-X or
>>>>Moonsked. I can't help with 3.
>>>>
>>>>Taking today as an example, total of 1 and 2 for the moon vary from 
>>>>~
>>>>+3
>>>>to -4.5kHz at S-Band.
>>>>
>>>>With DSN satellites many of us use(d) JPL Horizons to calculate
>>>>Doppler shift for Deep Space missions.  Observing the Doppler shift
>>>>change when probes were captured by the target planet was quite
>>>>interesting (a slowly changing shift to a cyclic one).
>>>>
>>>>73
>>>>
>>>>Charlie G3WDG
>>>>
>>>> > I find that an interesting question. One would think that since
>>>> > the
>>>>moon
>>>>>orbits the earth at a much much slower rate than a satellite that
>>>>>there would be almost no Doppler correction required. If you
>>>>>compensate for the speed of the orbit around the moon that is also
>>>>>at a much lower speed than a Earth satellite would be traveling at.
>>>>>Earth satellites are in the 17,000 mph range and moon satellites 
>>>>>are
>>>>>in the 2000 mile an hour range orbiting speed. Also the chance that
>>>>>the satellite orbiting the moon could be at such an axis where it 
>>>>>is
>>>>>in full visibility the earth the whole time, at that point there
>>>>>would not be a Doppler correction based upon satellite velocity 
>>>>>only
>>>>>the moon's velocity. Will be interesting to hear the experts chime
>>>>>in on this.
>>>>>
>>>>>Michael Vivona
>>>>>Sent from my iPad
>>>>>
>>>>>On May 25, 2018, at 5:49 PM, Stefan Wagener <wageners at gmail.com>
>>>>>wrote:
>>>>>
>>>>>The problem will not be the pointing (you could just point to the
>>>>>moon :-) Pending distance, speed and orbit around the moon and
>>>>>position to earth, you might have a difficult time adjusting for
>>>>>doppler. I let more knowledgable folks chip in on this one.
>>>>>
>>>>>Stefan, VE4NSA
>>>>>
>>>>>>On Fri, May 25, 2018 at 2:40 PM Jordan Trewitt
>>>>>><jmtrewitt at gmail.com>
>>>>>>wrote:
>>>>>>
>>>>>>If it was the 70 cm downlink, you might be able to schedule
>>>>>>something with someone else's SATNOGS station (idk how that'd work
>>>>>>with getting a rotator to work though), if they have a large 
>>>>>>enough
>>>>>>yagi that is.
>>>>>>-Jordan
>>>>>>KF5COQ
>>>>>>
>>>>>>>On Fri, May 25, 2018, 12:46 PM Zach Metzinger 
>>>>>>><zmetzing at pobox.com>
>>>>>>>wrote:
>>>>>>>
>>>>>>>>On 05/25/18 11:25, Nico Janssen wrote:
>>>>>>>>
>>>>>>>>It is confirmed from China that LongJiang 2 has performed a
>>>>>>>>successful braking maneuver, so that it is now in lunar orbit.
>>>>>>>>No further details yet.
>>>>>>>Nico,
>>>>>>>
>>>>>>>Do you know of any WebSDRs which are pointed and tuned to the
>>>>>>>downlink signals?
>>>>>>>
>>>>>>>73,
>>>>>>>
>>>>>>>--- Zach
>>>>>>>N0ZGO
>>
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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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