bionic (8) aprsmon.8.gz

NAME

       aprsmon - monitor APRS AX.25 traffic for javAPRS

SYNOPSIS

       aprsmon [-a] [-m] [-r] [-k minutes] [-p port] [-t title] [-i infofile]

DESCRIPTION

       Aprsmon  uses  SOCK_PACKET  facilities to provide a network monitor of all AX.25 UI text traffic heard by
       the system.  It is based on listen(1).

       Aprsmon collects (-m) or displays standard AX.25 UI text frames in a format similar to that output  by  a
       standard TNC in "Monitor ON" mode and is intended to be used with programs like javAPRS which wish to see
       a TNC data stream over a TCP connection.  When the aprsmon master has been running for a while and a  new
       aprsmon  slave starts up, first all saved up reports are sent, then a title line indicating the beginning
       of live data is sent, and new reports are sent as received.

       Compressed position and telemetry reports as generated by the APRS Mic Encoder are  translated  into  the
       conventional  uncompressed  APRS  Micro-Interface-Module (MIM) telemtry format so that these stations are
       visible in javAPRS.  Reports containing a TheNet X1J4 beacon header are also  edited  to  strip  off  the
       header making these nodes visible in javAPRS as well.

OPTIONS

       -a        Allow for the monitoring of outgoing frames as well as incoming ones.

       -r        Choose "raw" mode which allows non-printable data through.

       -p port   Monitor  only  those  frames received on a particular port, by default all AX.25 interfaces are
                 monitored.

       -m        "Master" mode.  Retain monitored data for the number of minutes specified with the -k option in
                 a shared memory segment.

       -k minutes
                 Retain monitored packets going back the given number of minutes.  Default is 30.

       -t title  Sets  the javAPRS or aprsd title string.  Default is "Live data from Linux." For use with aprsd
                 the format must be something like "aprsmon v2.4.4 padd padb." pada and padb  can  be  anything,
                 and are ignored but you *must* have 4 words in all.

       -i infofile
                 Infofile  is  the path to the file that the aprsmon master writes the shared memory segment and
                 semaphore id's into.  Default is "/var/ax25/aprsmon.info."

javAPRS CONFIGURATION

       Set up one aprsmon master running on your system to collect historical data going back a while.  You will
       probably want to set up an /etc/rc.d/init.d script for this.

       aprsmon -a -m&

       Add an entry into /etc/services with the port number you want javAPRS to connect on.  For example:

       aprs      14439/tcp # APRS monitor on 144.39

       Add an entry into /etc/inetd.conf for this service:

       aprs stream tcp nowait root /usr/sbin/aprsmon aprsmon -a

       To test, simply "telnet localhost aprs".  To use with javAPRS, set, for example,

       <PARAM name = "dataFile1" value = "netc:14439:localhost">
       in your HTML file as described in the javAPRS documentation, and then use appletviewer to run javAPRS:
       appletviewer mydemo.html

Mic-E to MIM Translation

       The  Mic-E reduces the duration of packet noise on a voice frequency by encoding its data in a compressed
       form, some of which is binary.  Some APRS-decoding software, notably javAPRS, is unable to deal with this
       data.  To solve this problem aprsmon expands the Mic-E packet into one or two MIM packets as follows:

       @ddhhmmzDDMM.hhN/DDDMM.hhW$cse/spd/E>mon/Mm/status
       T#MIC,aaabbbcccdddeeefffComments

       ddhhmm    is the UTC day and time the packet was received by the host running aprsmon.

       DDMM.hhN  is the latitude.

       /         is the symbol table selection (/ or \).

       DDDMM.hhW is the longitude.

       $         is the symbol.

       cse,spd   are course and speed.

       E         is the type of Mic-Encoder:

                 E - TAPR Mic-Encoder
                 T - Kenwood TH-D7

       m         is the status message number, and

       status    is the status message number expanded as follows:

                 0 -  Off duty..
                 1 -  Enroute...
                 2 -  In Service
                 3 -  Returning.
                 4 -  Committed.
                 5 -  Special...
                 6 -  PRIORITY..
                 7 -  EMERGENCY.

       aaa,bbb,ccc,ddd,eee,fff
                 are the values of the telemetry channels.

FILES

       /etc/ax25/axports /var/ax25/aprsmon.info

SEE ALSO

       call(1),   listen(1),   beacon(1),   ax25(4),   axattach(8),  http://www.bridge.net/~sdimse/javAPRS.html,
       http://www.tapr.org, http://www.aprs.net, MIC-E.TXT,TELEMTRY.TXT,PROTOCOL.TXT

AUTHOR

       Alan Crosswell, n2ygk@weca.org