[amsat-bb] Re: ISS Digipeaer over Japan

Edward R. Cole kl7uw at acsalaska.net
Sun Mar 13 10:49:31 PDT 2011

At 07:28 AM 3/13/2011, Bob Bruninga wrote:
>Toyo san,
>A few more ideas.  It is easy to manually estimate ISS pass times 
>every day once you have heard a pass.
>See: http://aprs.org/MobileLEOtracking.html
>1) ISS over Japan today is between about 0830 to 1830 JST.
>2) When you hear the first pass, then you will have additional 
>passes every 91 minutes or so that day.
>3) Each day a given GOOD pass is 23 minutes later.
>4) But overall-long-term pattern is moving earlier every other day 
>by 51 minutes.
>5) So in one week from now, the time window will be 0600 to 1600
>6)  The pass pattern is about the same.  First 2 passes peak to the 
>SE, then NW.  Then a low northern pass, then the last two passes are 
>NE and then SW.
>You can get EXACT pass times from http://heavens-above.com and 
>select a city.  However, this web page does not show the 1 or 2 low 
>passes each day below 10 degrees elevation.
>The problem with using the ISS digipeater is that the survivors in 
>the devistated area do not know the frequency (145.825).  One way to 
>solve this is to look for opportunity for someone to take a portable 
>digipeater on an airplane over devistated area.  The new TH-D72 HT 
>can digipeat now!  So have someone with a D72 catch a ride in an 
>aircraft one day.
>The D72 can BEACON on 144.64 a MESSAGE BULLETIN with info about the 
>ISS digipeater and the time-window.  WHile it is aloft, it can also 
>act as a digipeater on Japanese APRS channel 144.64 and can also 
>capture a list of any APRS stations or mobiles on the air.
>The short bulletins might say something like this:
>MSG: ISS Digi on 145.825 between 0830 to 1830
>MSG: Passes are 6 min long every 91 minutes
>MSG: Every day, passes are 23 minutes later
>MSG: Time window moves EARLIER 51m every 2 days
>Keep bulletins to under 45 characters to make sure that every radio 
>display can see the full bulletin (D7 screen limit).

All good suggestions except the last one.  I think the road system is 
devastated as all the relief work has been by air in the severest hit 
areas.  ~ Ed , KL7UW

>But in small area like Japan, I think it might be easier just to try 
>to drive APRS mobiles (acting as digipeaters) to nearby hill tops on 
>144.64 normal APRS Japanese Frequency and keep everyone on same 
>frequency without confusion.
>Bob, WB4APR
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73, Ed - KL7UW, WD2XSH/45
BP40IQ   500 KHz - 10-GHz   www.kl7uw.com
EME: 144-1.4kw, 432-100w, 1296-testing*, 3400-winter?
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