[amsat-bb] LongJiang and Doppler correction

Wed May 30 08:35:38 UTC 2018

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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