Using APRS satellites in disaster areas

DISCLAIMER:
This document is NOT a recommendation to use APRS via ISS in a disaster. There are many other Ham Radio Communications capabilities that are better under any given circumstances. This document was only written to tell "HOW" to use APRS and packet via ISS for emergency operations in a disaster area,*IF* such use was necessary for a given emergent need.

This article describes how to use the ARISS and possibly PCSAT2 system (on ISS) for tracking and communicating with APRS assets in the Hurricane affected areas.
It covers 3 topics:

1) Knowing when the ISS is in view without a PC
2) Settings for ISS and PCSAT2 digipeater
3) How to send an Email from your APRS or D7 or D700 APRS mobile/HT or normal packet.

KNOWING WHEN ISS IS IN VIEW:

DAILY 1: At 30 deg latitude (New Orleans), you will get two contact window periods a day and each period will give you 2 or 3 pass opportunities. Today these Windows are 7-10 PM and 2-6 AM daylight time (applies everwhere at this N.latitude).

DAILY 2: If you hear a pass early in a window, then you will hear another one 97 minutes later. And if lucky, another 97 minutes after that.

DAILY 3: Similarly, if you hear a good pass during the first window, then you will hear another good pass in the second window exactly 8 hours (and 2 mins) later.

NEXT DAY: If you hear a pass on ONE day, then you will hear another one the NEXT day 27 mins LATER. (AND/OR 68 minutes EARLIER.)

MULTI-DAY: For longer range multi-day planning, these "window-periods" slide EARLIER by 22 minutes per day (but the exact times follow only the "daily" rules above")

WIth these simple rules and keeping a log of when you hear ISS passes on your dashboard, it is easy to predict future passes and operating times for weeks or longer. You can work up simple plans like this for ECHO, SO50 and any
other satellite.

NEW-START: If you are starting new, then all you have to do is monitor continuously during one of the windows until you do hear a pass, and from then on, you can figure your own schedule. Just remember to slide the window earlier by
22 minutes per day from the times above for 1 Sept.

SETTINGS: There are two digital assets on ISS and both digipeat using the path of "VIA ARISS"

ARISS: 145.800 down, 145.99 up PCSAT2: 435.275 +/- 10 Khz, 145.825 up

Use ARISS in the disaster area and mobile since it is 10 dB stronger, has 9 dB less path loss on the downlink to other omni's, has more IGate stations and has no appreciable Doppler.

PBBS: If you have a portable cross band beam antenna, and can remember to TRACK ISS, and point the beam, and tune the downlink for Doppler, then you are welcome to use the PCSAT2 BBS for longer paragraph type trafffic, though you
must remember that maintainig a "connection" via a satellite is problematic at best. The PBBS callsign is MAIL.

Only USA STATIONS IN the disaster area should logon to the BBS with emergency or priority traffic. No other USA stations should attempt to use the BBS for ANY purpose even emergency or priority traffic to or from someone
in the disaster area.

Instead, Let stations in other parts of the world be the gateways for downloading any such traffic or sending back replies.

EMAIL: APRS is a one-line message system. But you can send email if you can fit the email address and text in the same line. Anyone can do this via ISS using the APRS protocol if they have either an APRS system, a D7 walkie
talkie or a D700 mobile, or even a simple radio/TNC.

EMAIL FROM APRS, D7 or D700:
- Set your path to go via ARISS
- Send the message line TO "email"
- Make the first part of the message be the email address and then enter your very brief email text continuing on the same message line. For any TNC or packet system, simply make the AX.25 address be APRS and send the packet as a UI digipeated packet via ARISS.

If you are successful via ISS, your radio will display "MY MESSAGE" to confirm the packet got digipeted. If it did, then cancel the remaining message retries to reduce QRM.
Do not expect a message ack.

EMAIL FROM ANY PACKET SYSTEM:
To do this you must make your packet look like an APRS message packet:
- Set your UNPROTO APRS VIA ARISS
- Go to converse
- Type :EMAILssss:eeee@eee.eee.eee text
Where the four "ssss" are four spaces
Where eeee@eee.eee.eee is the email address
Where text is your text.

If you see it digipeated, then your email will probably be successful. If not, you have to type the whole thing again, error free to try again.

CONCLUSION:
This document is *NOT* a recommendation to use APRS via ISS in a disaster. There are many other Ham Radio Communications capabilities that are better under any given circumstances.

This document was only written to tell "HOW" to use APRS and packet via ISS for emergency operations in a disaster area, *IF* such use had any immediate application.

But in any case, unattended packet beacons via ISS are NEVER welcome and especially over the USA at this time.

This email is provided for what-it-is-worth, and is not endorsed nor approved by ARISS at this time. I just thought it would be useful to have it as a baseline...

de Wb4APR, Bob
US Naval Academy
PCSAT2 Ground station

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