[amsat-bb] APRS satellite dual hop

[Pavel Milanes Costa]

Both Footprints must kiss or better overlap.

73 CO7WT

El 9/11/18 a las 14:01, E.Mike McCardel escribió:
> Bob,
>
> How close would the two satellites need to be with each other to hear each other?
>
> EMike McCardel, AA8EM
> Senior Editor AMSAT News Service
> Past AMSAT-NA VP Educational Relations
>
>
>> On Nov 8, 2018, at 4:25 PM, Robert Bruninga <bruninga at usna.edu> wrote:
>>
>> My bad.  I misread it as a dual hop.  The dual *s put in by some TNC's
>> confused me.
>>
>> Here is how a 2 hop packet transmitted as ARISS,ARISS would look on the
>> downlink in a normal TNC:
>>
>> PSAT,ARISS,RS0ISS* going one way or   (least likely)
>> RS0ISS,PSAT,ARISS* going the other      (more possible)
>>
>> And remember, no one will find these on the ARISS or PSAT downlink pages
>> because most likely only the first hop will be captured and the second hop
>> will be rejected as a dupe.
>>
>> That is why everyone should always watch the downlink live if they want to
>> capture one of those rare 2-hop APRS packets.
>>
>> HERE IS HOW TO DO IT:
>>
>> Challenges: Since PSAT has only a 0.2W transmitter, the ISS is simply
>> never going to hear it.  But the chance of PSAT hearing the ISS is 20
>> times better.  SO the best chance of success is via ISS first then PSAT.
>> But if they both hear the uplink packet, then PSAT will be transmitting at
>> the same time ISS is and so a dual hop is blocked.
>>
>> So here is the best scenario for dual hop success:
>>
>> 1) Transmit stations via ARISS,ARISS on one continent hitting only ISS and
>> NOT hitting PSAT at same time
>> 2) PSAT in footprint of ISS but also over mostly ocean so it might hear
>> ISS without lots of user QRM
>> 4) Receiving station on a distant continent looking out over water towards
>> PSAT.
>>
>> Then chances could be good.  Notice, the transmitting stations can be any
>> users as long as they are using the ARISS,ARISS path.  So the only person
>> that has to do any planning is simply coastal receiving stations.
>>
>> With both ISS and PSAT now operational, this would be a good time for all
>> users to be using the transmit dual hop path of ARISS,ARISS to maximize
>> someone else on some other continent receiving them!
>>
>> -----Original Message-----
>>
>>> Fm N0AN-10 To CQ Via PSAT*,ARISS* <UI pid=F0 Len=43 >[14:50:57]
>>> =4206.15N/09402.30W`73 v. ISS de Hasan N0AN
>>>
>>> Fm WD9EWK To APK002 Via PSAT*,ARISS* <UI pid=F0 Len=21 >[14:51:11]
>>> :N0AN-10  :hi dm43{N
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