[aprssig] RAFT/ANDE Progress report

[Robert Bruninga]

ANDE and RAFT APRS satellites are operatonal.  There is a local
TV clip now on
the web page where the students discuss their satellite
projects.  See
http://www.ew.usna.edu/~bruninga/ande-raft-ops.html

Both signals are weak and require a beam and high elevations to
hear them.  As of this time, RAFT speech is enabled for special
testing only in accordance with the User Service Agreement:
http://www.ew.usna.edu/~bruninga/ande/ANDEcontract.txt

During a 58 degrees max elevation pass, at about 45 degrees
elevation, PA3GUO reports a successful voice packet via RAFT.
The MP3 file is on the ANDE-RAFT-OPS web page above.  A high
elevation pass is usually required.

PLEASE NOTE!  RAFT is underpowered for this voice mission, and
so this capability should only be used by special demo stations
and for special events or tests.  The downlink is very weak and
needs a beam and a high elevation pass to hear it.  DO NOT
TRANSMIT A VOICE PACKET IF YOU CANNOT HEAR THE DOWNLINK.  You
must adhere to the user service agreement above to use this
capability. 

When ACTIVATED, RAFT will speak an APRS formatted MESSAGE
addressed to the callsign of TALK.  This APRS Message packet was
Transmitted by PA3GUO:   

>   PA3GUO-8>APRS,RAFT*::TALK   :henk says hello

First the packet is digipeated (lets you know it received it).
Then (up to 10 seconds later), it should SPEAK the packet.  In
this case RAFT spoke:

>  "PA3GUO" + "says" + "henk says hello" 

Although the Speech synthesizer is ENABLED, it is normally OFF.
To use it, someone in the footprint has to activate the voice
module with a CONNECT REQUEST to "RAFT".  On hearing a connect
request, (the connecting station can do nothing else), RAFT
responds in voice with "Welcome to TextSpeak".  At that point,
RAFT will speak any APRS formatted MESSAGES from anyone to TALK.
Again, notice that if you see the successfully DIGIPEATED
packet, then it will speak it, although there might be up to a
10 second delay.  If you see such a successful APRS MESSGE to
TALK digipeated, then everyone should hold off until it gets a
chance to speak it.

Notice the APRS MESSAGE format carefully.  The callsign TALK is
bracketed with colons and is padded to 9 characters with 5
spaces on the end.

Oh, This speech was enabled with simply the connection of an off
the shelf $200 text-to-speech module connected to the serial
port of the spaeccraft KPC3+ TNC.  Kantronics made a slight
software mode to replace the normal packet header with "CALLSIGN
SAYS" before the packet is sent out the serial port.
With this mod, you can use a radio, TNC and this voice module to
create "voice at a distance"...  But the high cost of the voice
module will probably prohibit much terrestrial applications..

Bob Bruninga, WB4APR
US Naval Academy Satellite Lab.