ISS APRS tips?


John St. John
 

Hi there,
I have tried and have not succeeded twice now to get an APRS packet through ISS that shows up on aprs.fi or ariss.net. I hear other peoples packets though and I have even gotten messages that show up in my message list on my D72. I have mostly been following the article that Joe Kornowski and Patrick Stoddard wrote in 2017 for my radio. There are a couple of potential things I am wondering may have gone wrong:

1) Maybe my 5w handheld/arrow 2 setup is getting overpowered by other hams. I live next to San Francisco so there is a lot of activity nearby. I did try and get quite a few beacons through, in case one of them stuck. 

2) I noticed that I hadn’t updated my time and time zone for daylight savings. Could this cause problems? Do APRS packets even have the time in them?

3) In the book Amsats and Hamsats by Andrew Barron. He recommends adding “ARISS,SGATE,WIDE2-1” as the packet path to show up on ariss.net. Patrick and others I have seen say that you only need to have ARISS in your path. Andrew says that: “SGATE tells the satellite to pass your position report on to the terrestrial network, and WIDE2-1 is the path used once the beacon is in the terrestrial network”. Is that just wrong? One thing I was thinking/guessing is that these settings may have the side effect of getting other terrestrial stations to amplify my packet? Not sure if that guess is right. 

Anyways thanks for your time and help!

Best,
John K6POO 


John St. John
 

Ok I am seeing a pattern that may be nothing. It looks like everyone who is getting captured on ariss.net, and also by someone in my local radio club, has NA1SS or NA1SS* in their packet path. Here are some examples, am I reading this correctly? Is this a requirement? Or maybe this is just telling me where the packets went? Again thanks for your time helping me learn this stuff! The only signals in the following list (and a much longer list on ariss.net) without NA1SS* after the ] section of the APRS packet are the beacons from the ISS itself which have NA1SS as the sender. Should I be adding NA1SS* (with the asterisk) to my packet path maybe? I am a little bummed if that is the case because I was also hoping that I could construct a path that would be picked up by other satellites. Maybe something like “NA1SS*,APRSAT,ARISS” as something that would catch all of the cases? Again I don’t really know what I am doing with these packet path things...

00:10:04:33 : K0KOC-7]3Y2S1Y,NA1SS*,qAO,WB2QGZ-10:'i4wl #/]=
00:10:04:45 : K1WY]TQTU7T,NA1SS*,RS0ISS,qAO,N2QKV-10:'dGRl -/]
00:10:04:46 : N1NCB-1]APOT21,NA1SS*,APRSAT,qAO,N2QKV-10:/053533h4355.01N\06954.34W_104/000/A=00006112.9V 63F EPE005
00:10:04:47 : W2PSK]T0RW1W,NA1SS*,qAO,W2THC-10:`f36l -/`South River, NJ USA_"
00:10:04:57 : K0KOC-7]3Y2S1Y,NA1SS*,qAR,KG4PID-12:'i4wl #/]www.K0KOC.com=
00:10:05:23 : K9ILU-8]TQ1S2Y,NA1SS*,qAO,KB4YTM-12:`r5%l -/`_%
00:10:05:36 : K0KOC-7]3Y2S1Y,NA1SS*,qAo,WA8LMF-4:'i4wl #/]=
00:10:05:47 : NA1SS]0P0PR7,APRSAT,qAO,VE3VWS-6:'v&l SI]ARISS-International Space Station=
00:10:06:03 : W2PSK]T0RW1W,NA1SS*,qAR,KG4PID-12:`f36l -/`South River, NJ USA_"
00:10:06:29 : K1WY]TQTU7T,NA1SS*,RS0ISS,qAo,WA8LMF-4:'dGRl -/]
00:10:06:35 : K9ILU-8]TQ1S2Y,NA1SS*,qAo,WA8LMF-4:`r5%l -/`_%
00:10:08:05 : W2PSK]T0RW1W,NA1SS*,qAR,KG4PID-12:`f36l -/`South River, NJ USA_"
00:10:08:52 : NA1SS]0P0PR7,APRSAT,qAo,WA8LMF-4:'v&l SI]ARISS-International Space Station=
00:10:11:06 : NA1SS]0P0PR7,APRSAT,qAO,N6BA-10:'v&l SI]ARISS-International Space Station=

On Mar 19, 2021, 8:13 AM -0700, John St. John via groups.io <johnthesaintjohn@...>, wrote:
Hi there,
I have tried and have not succeeded twice now to get an APRS packet through ISS that shows up on aprs.fi or ariss.net. I hear other peoples packets though and I have even gotten messages that show up in my message list on my D72. I have mostly been following the article that Joe Kornowski and Patrick Stoddard wrote in 2017 for my radio. There are a couple of potential things I am wondering may have gone wrong:

1) Maybe my 5w handheld/arrow 2 setup is getting overpowered by other hams. I live next to San Francisco so there is a lot of activity nearby. I did try and get quite a few beacons through, in case one of them stuck. 

2) I noticed that I hadn’t updated my time and time zone for daylight savings. Could this cause problems? Do APRS packets even have the time in them?

3) In the book Amsats and Hamsats by Andrew Barron. He recommends adding “ARISS,SGATE,WIDE2-1” as the packet path to show up on ariss.net. Patrick and others I have seen say that you only need to have ARISS in your path. Andrew says that: “SGATE tells the satellite to pass your position report on to the terrestrial network, and WIDE2-1 is the path used once the beacon is in the terrestrial network”. Is that just wrong? One thing I was thinking/guessing is that these settings may have the side effect of getting other terrestrial stations to amplify my packet? Not sure if that guess is right. 

Anyways thanks for your time and help!

Best,
John K6POO 


Rob VE3RXH
 

John

I am relatively new to this but have had success with a path of:  ARISS, WIDE2-1.  I think you just need to keep trying.  I have read that there are a shortage of SGATEs and so it all depends on:

a) did your packet get received by the ISS and digipeated? and
b) did the rebroadcast from the ISS get received by an SGATE and passed to the APRS internet system?

To have success with both of those factors you need to keep trying!

I think that a path of "ARISS" is changed to "NA1SS*" by the ISS, you don't put that in your path, put "ARISS".

From your packet list in the second post above:

00:10:04:33 : K0KOC-7]3Y2S1Y,NA1SS*,qAO,WB2QGZ-10:'i4wl #/]=

I decode that as being at "00:10:04:33" hours, a packet of data from callsign "K0KOC-7" was received by the ISS and digipeated by "NA1SS*", that was then received by SGATE callsign "WB2QGZ-10" and passed to the APRS internet system.

I use a Kenwood TM-D700 and a Comet GP3 ground plane antenna with 25W.  Maybe less than 50% of my packets get to an SGATE per pass of the ISS.  I'm in eastern Ontario, Canada so unless the ISS is going south towards greater population (ie more SGATEs) then my success rate is low.

Hope that helps.

73
Rob


John St. John
 

Thank you Rob! 
I have had a few successful digipeats off of the ISS now. I think you are right that things were too busy when I tried the first few times. Everyone was excited about the radio being fixed :) 
Best,
John 

On Apr 28, 2021, 10:25 AM -0700, Rob VE3RXH via groups.io <rjhaddow@...>, wrote:
John

I am relatively new to this but have had success with a path of:  ARISS, WIDE2-1.  I think you just need to keep trying.  I have read that there are a shortage of SGATEs and so it all depends on:

a) did your packet get received by the ISS and digipeated? and
b) did the rebroadcast from the ISS get received by an SGATE and passed to the APRS internet system?

To have success with both of those factors you need to keep trying!

I think that a path of "ARISS" is changed to "NA1SS*" by the ISS, you don't put that in your path, put "ARISS".

From your packet list in the second post above:

00:10:04:33 : K0KOC-7]3Y2S1Y,NA1SS*,qAO,WB2QGZ-10:'i4wl #/]=

I decode that as being at "00:10:04:33" hours, a packet of data from callsign "K0KOC-7" was received by the ISS and digipeated by "NA1SS*", that was then received by SGATE callsign "WB2QGZ-10" and passed to the APRS internet system.

I use a Kenwood TM-D700 and a Comet GP3 ground plane antenna with 25W.  Maybe less than 50% of my packets get to an SGATE per pass of the ISS.  I'm in eastern Ontario, Canada so unless the ISS is going south towards greater population (ie more SGATEs) then my success rate is low.

Hope that helps.

73
Rob