by Peter Stevenson on October 2, 2020 under hamradio

8 minute read

Using APRS to contact the ISS

Radios

Good enough for the ISS good enough for me. I was about to buy one of the following Kenwood radios.

TM-D710

TM-D100

aprs-tx.sh

It’s important you set path via ariss and not WIDE1-1 or WIDE2-1 as WIDE is for terrestrial APRS.

I had a sudden idea pop into my head on how to do a TX with my IC-7100.

My hack job script below got my packet on the map using a IC-7100 running 25 w into a collinear. Back to earth via DL8NDR iGate.

aprs-2e0pgs-6.mp3 is a audio recording I made of a encoded APRS packet which includes my location and call sign.

I have a previous blog post on rigctl: here

$ cat aprs-tx.sh 
#!/bin/bash

/usr/local/bin/rigctl -r /dev/ttyUSB0 -m 370 T 1
mpv aprs-2e0pgs-6.mp3 --audio-device='pulse/alsa_output.usb-Burr-Brown_from_TI_USB_Audio_CODEC-00.analog-stereo'
/usr/local/bin/rigctl -r /dev/ttyUSB0 -m 370 T 0

watch -n 60 ./aprs-tx.sh

ariss-website-map

ariss-website-log

aprs-fi

While I am at it we can decode via GQRX and UDP out to multimon-ng. It worked but was a bit hit and miss on the message probably due to doppler shift. Below is some of the decodes I had via multimon-ng. I later enabled --timestamps flag.

AFSK1200: fm ? to D3CZ5\-10 QSO Nr 11776 I15- pid=35
..D

AFSK1200: fm ? to :GDXU/-5 QSO Nr 6693 I26^ pid=26
.1.x

AFSK1200: fm ? to 4(,0P+-3 QSO Nr 3846 I54v pid=FF
....

AFSK1200: fm ? to R7=S16-1 QSO Nr 5165 RNR5v pid=B3
.q...39...

2020-06-12 14:04:44: AFSK1200: fm ? to '5(;+"-6 QSO Nr 9632 REJ1+ pid=93
2020-06-12 14:04:44: ....

2020-06-12 21:07:13: AFSK1200: fm ? to ]M/K'W-1 QSO Nr 2258 I66^ pid=E7
2020-06-12 21:07:13: ...;..

gqrx-iss-doppler

Dire Wolf

I have played with Dire Wolf briefly in the past. I wasn’t aware just how functionally complete it was!

User Guide

The PDF User Guide is very comprehensive see below useful headings.

9.6.3 SATgate example
9.10.5 SATgate mode
9.10.7 Log Everything Going In and Out

Setup

Let’s set up a more proper TX and RX APRS modem with iGate and SatGate function. I believe SatGate is just a fancy term for a iGate listening on satellite frequencies e.g. 145.825

sudo apt-get install libasound2-dev
git clone https://www.github.com/wb2osz/direwolf
cd direwolf
make
sudo make install
make install-conf

Use aplay -l to find hardware device ID of sound card. See IC-7100 blog post on AF output mode if applicable.

direwolf-satgate.conf

This is my current config file.

ADEVICE  plughw:4,0

ACHANNELS 1

CHANNEL 0

MYCALL 2E0PGS-6

MODEM 1200

PTT RIG 370 /dev/ttyUSB0 

AGWPORT 8000
KISSPORT 8001

PBEACON delay=1 every=1 overlay=S symbol="dish" lat=12^34.56N long=1^23.45W power=25 height=20 gain=5 comment="www.m3pgs.co.uk" via=ARISS

IGSERVER euro.aprs2.net 

IGLOGIN 2E0PGS-6 12345

IGTXLIMIT 6 10

FILTER 0 ig b/RS0ISS | d/RS0ISS

LOGFILE /home/peter/direwolf-satgate-rx.log

Running direwolf: direwolf -a 100 -t 0 -d ii -d fff -c ~/direwolf-satgate.conf | tee -a ~/direwolf-satgate-console.log

Test it decodes use another radio to send a packet over 145.825.

Test it beacons use another device with a decoder.

I have my SatGate beacon currently only going via RF to the ISS. Maybe I will have it use TCPIP beacons at some point. I see most hardcore SatGate operators have two IDs/radios one for a TCPIP beacon SatGate and one is a standalone RF only beacon so that way they advertise their SatGate 24/7 and still have a ID that shows only when the ISS received them.

LOGFILE

These are full decodes.

chan,utime,isotime,source,heard,level,error,dti,name,symbol,latitude,longitude,speed,course,altitude,frequency,offset,tone,system,status,telemetry,comment
0,1592131941,2020-06-14T10:52:21Z,EI7BFB,RS0ISS,22(8/8),1,=,EI7BFB,/`,53.390833,-6.288333,,,,,,,,,,"EMAIL: EI7BFB1@gmail.com, Best Wishes & Good Health {UISS54}"
0,1592388330,2020-06-17T10:05:30Z,EA2AUK,RS0ISS,20(8/9),0,=,EA2AUK,/-,40.327833,-1.094333,,,,,,,,,,[Pedro en Teruel Via ISS 73]
0,1592388343,2020-06-17T10:05:43Z,IK1COA-1,RS0ISS,19(9/9),0,',IK1COA-1,\K,44.359333,9.223833,0.0,,,,,,Kenwood TM-D710,In Service,,73 DE IK1COA  Will End !
0,1592388347,2020-06-17T10:05:47Z,M0TDW-7,RS0ISS,22(8/9),1,`,M0TDW-7,/[,51.361000,-1.546333,0.0,322.0,141.0,,,,Mic-Emsg,In Service,,de Bill IO91fi 73 M0TDW_0

Console

This is a console output that I tee to a log file for more verbose info about the IGate using flags: -d ii -d fff.

I was tweaking my config here and there so there are some errors. However I got some nice decodes coming in towards the end of my config alterations. The LOGFILE seems to not work with ~/ path so explicitly state the full path in the config.

Digipeater RS0ISS audio level = 24(9/9)   [SINGLE]   ____:____
[0.4] M0TDW-7>U1RQVV,RS0ISS*,WIDE2-1:`w<jl"x[/`"5K}de Bill IO91fi 73 M0TDW_0<0x0d>
MIC-E, Human, Mic-Emsg, In Service
N 51 21.6600, W 001 32.7800, 0 MPH, course 292, alt 469 ft
de Bill IO91fi 73 M0TDW_0

RS0ISS-1 audio level = 20(9/8)   [NONE]   ||||||___
[0.2] RS0ISS-1>EC5W-1:(RR res, n(r)=5, f=1)

RS0ISS-1 audio level = 20(9/9)   [NONE]   _|||||___
[0.3] RS0ISS-1>EC5W-1:(I cmd, n(s)=3, n(r)=6, p=0, pid=0xf0)<0x0d>

RS0ISS-1 audio level = 19(8/9)   [NONE]   ||||||___
[0.2] RS0ISS-1>EC5W-1:(I cmd, n(s)=4, n(r)=6, p=0, pid=0xf0)<0x0d>

RS0ISS-1 audio level = 18(9/9)   [NONE]   |||||||__
[0.3] RS0ISS-1>EC5W-1:(I cmd, n(s)=5, n(r)=6, p=0, pid=0xf0)<0x0d>

RS0ISS-1 audio level = 20(9/9)   [NONE]   |||||||__
[0.3] RS0ISS-1>EC5W-1:(I cmd, n(s)=6, n(r)=6, p=1, pid=0xf0)International Space Station<0x0d>

RS0ISS-1 audio level = 23(9/9)   [NONE]   ____|____
[0.4] RS0ISS-1>EC5W-1:(RR cmd, n(r)=6, p=1)

RS0ISS-1 audio level = 25(9/8)   [NONE]   ___||____
[0.3] RS0ISS-1>EC5W-1:(I cmd, n(s)=1, n(r)=6, p=0, pid=0xf0)<0x0d>

RS0ISS-1 audio level = 21(8/9)   [NONE]   ___|||___
[0.4] RS0ISS-1>EA2BJM-2:(RR cmd, n(r)=0, p=1)
[rx>ig] #

RS0ISS-1 audio level = 19(8/8)   [NONE]   |||||||__
[0.3] RS0ISS-1>EA2BJM-2:(RR cmd, n(r)=0, p=1)

RS0ISS audio level = 19(8/9)   [NONE]   ||||||___
[0.2] RS0ISS>CQ:Logged on to RS0ISS's Personal Message System<0x0d>
Unknown APRS Data Type Indicator "L"
Opening log file "~/direwolf-satgate-rx.log"
Can't open log file "~/direwolf-satgate-rx.log" for write.
No such file or directory

Rx IGate: Truncated information part at CR.
rx_to_ig_allow? 54969 "RS0ISS>CQ:Logged on to RS0ISS's Personal Message System"
rx_to_ig_allow? YES, no dedupe checking
[rx>ig] RS0ISS>CQ,qAO,2E0PGS-6:Logged on to RS0ISS's Personal Message System

RS0ISS audio level = 20(8/9)   [SINGLE]   _:::::___
[0.3] RS0ISS>CQ:on board the International Space Station<0x0d>
Unknown APRS Data Type Indicator "o"

RS0ISS audio level = 19(8/9)   [NONE]   ||||||:__
[0.3] RS0ISS>CQ:<0x0d>
Unknown APRS Data Type Indicator "^M"
Rx IGate: Truncated information part at CR.
Rx IGate: Information part length is zero.

RS0ISS audio level = 20(9/9)   [NONE]   ::::||___
[0.4] RS0ISS>CQ:You have mail waiting.<0x0d>
Unknown APRS Data Type Indicator "Y"
Rx IGate: Truncated information part at CR.
rx_to_ig_allow? 43383 "RS0ISS>CQ:You have mail waiting."
rx_to_ig_allow? YES, no dedupe checking
[rx>ig] RS0ISS>CQ,qAO,2E0PGS-6:You have mail waiting.

RS0ISS audio level = 19(9/8)   [NONE]   ||||||___
[0.2] RS0ISS>CQ:<0x0d>
Unknown APRS Data Type Indicator "^M"
Rx IGate: Truncated information part at CR.
Rx IGate: Information part length is zero.

RS0ISS audio level = 20(8/9)   [SINGLE]   _:::::___
[0.3] RS0ISS>CQ:Msg # Stat  Date     Time  To     From   @ BBS  Subject<0x0d>
Unknown APRS Data Type Indicator "M"

Digipeater RS0ISS audio level = 20(8/9)   [NONE]   :::|||___
[0.3] EA2AUK>CQ,RS0ISS*:=4019.67N/00105.66W-[Pedro en Teruel Via ISS 73]<0x0d>
Position, House
N 40 19.6700, W 001 05.6600
[Pedro en Teruel Via ISS 73]
Opening log file "/home/peter/direwolf-satgate-rx.log"
Rx IGate: Truncated information part at CR.
rx_to_ig_allow? 53197 "EA2AUK>CQ:=4019.67N/00105.66W-[Pedro en Teruel Via ISS 73]"
rx_to_ig_allow? YES, no dedupe checking
[rx>ig] EA2AUK>CQ,RS0ISS*,qAO,2E0PGS-6:=4019.67N/00105.66W-[Pedro en Teruel Via ISS 73]
[rx>ig] #

Digipeater RS0ISS audio level = 19(9/9)   [NONE]   ||||||___
[0.2] IK1COA-1>T4RQU6,RS0ISS*,APRSAT:'<0x7f>)Gl <0x1c>K\]73 DE IK1COA  Will End !=<0x0d>
MIC-E, Kenwood HT (W), Kenwood TM-D710, In Service
N 44 21.5600, E 009 13.4300, 0 MPH
73 DE IK1COA  Will End !
Rx IGate: Truncated information part at CR.
rx_to_ig_allow? 20902 "IK1COA-1>T4RQU6:')Gl K\]73 DE IK1COA  Will End !="
rx_to_ig_allow? YES, no dedupe checking
[rx>ig] IK1COA-1>T4RQU6,RS0ISS*,APRSAT,qAO,2E0PGS-6:'<0x7f>)Gl <0x1c>K\]73 DE IK1COA  Will End !=

Digipeater RS0ISS audio level = 22(8/9)   [SINGLE]   ____:____
[0.4] M0TDW-7>U1RQVV,RS0ISS*,WIDE2-1:`w<jl#2[/`"5I}de Bill IO91fi 73 M0TDW_0<0x0d>
MIC-E, Human, Mic-Emsg, In Service
N 51 21.6600, W 001 32.7800, 0 MPH, course 322, alt 463 ft
de Bill IO91fi 73 M0TDW_0
[rx>ig] #

Successfully IGated packets

Where I been first to IGate something and no duplicate packets were rejected on server side.

00:00:10:46 : EA2AUK]CQ,RS0ISS*,qAO,2E0PGS-6:=4019.67N/00105.66W-[Pedro en Teruel Via ISS 73]

SGATE path

Closing notes

I am yet to have the ISS hear my Dire Wolf beacon so there is more tweaking required with Dire Worlf.

Dire Worlf is currently working for decoding as a iGate/SatGate though.

However I am happy the ISS did hear my hack job script beacon.

I should try the ISS cross band voice repeater.

~~I should also try recieve ISS SSTV images.~~ See: ISS expedition 63 SSTV

IC-7100, APRS, GQRX, Bash,

I feedback.
Let me know what you think of this article on twitter @M3PGS or leave a comment below!

Working the ISS using APRS

Using APRS to contact the ISS

Radios

aprs-tx.sh

Dire Wolf

User Guide

Setup

direwolf-satgate.conf

LOGFILE

Console

Successfully IGated packets

SGATE path

Closing notes

Useful links

Working the ISS using APRS

Using APRS to contact the ISS

Radios

aprs-tx.sh

Dire Wolf

User Guide

Setup

direwolf-satgate.conf

Related blog posts

LOGFILE

Console

Successfully IGated packets

SGATE path

Closing notes

Useful links