[aprssig] APRS Situational Awareness

Stephen H. Smith wa8lmf2 at aol.com
Wed Apr 16 12:28:29 EDT 2008

John Galvin wrote:
>  Why can't we get rid of some of the unused symbols and replace them 
> with needed ICS symbols. The No. circle with an "S" overlay doesn't 
> quite make it. Stephen has been pretty good about fixing up the symbol 
> set so Stephen what say some new ICS symbols? Maybe a circle outline 
> capable of overlays with no background?

1)      I can only do updates that are blessed by the APRS standards 
setting committee.

2)     WB4APR seems to be totally incapable of RECEIVING email sent 
directly from me. Kieth (ve7gdh at rac.ca) also is reporting that his 
emails direct to Bob are bouncing.    Bob's email system seems to be 
suffering from the "Get Smart" syndrome; i.e. so locked down it can't 
communicate.   [ Remember Maxwell Smart Agent 86 and his non-conferences 
under the "Cone of Silence".? ]     Don't know if this is DOD paranoia 
or just an ISP issue....

3)     Decreeing new symbols is not a trivial task.  

AS I have pointed out many times before, the actual symbol graphic IS 
NOT TRANSMITTED.  Only a one or two character alpha-numeric code is sent 
over the air. This code causes the appropriate symbol to be selected 
from a set of graphics already stored on the recipient's machine.  
Everyone must change/update the stored symbol set in their program(s) 
before a newly-defined symbol set will become useful.

As an example of this problem, transmitting the standard symbol for 
"SSTV" (which I do from the car for my mobile SSTV "livecam") causes 
causes a thundercloud to show on findu.  [ This is the result of a 
symbol standards change OVER A DECADE AGO! ]

    * The only Windows APRS apps with symbol sets that can be readily
      updated are UIview and APRSplus.  
    * In  Win/MacAPRS, the symbols are embededed in the compiled  .EXE
      file (instead of being stored externally) and therefore
      inaccessible for changes. 
    * APRSpoint doesn't even use the standard APRS symbol set.  It only
      uses the standard Microsoft MapPoint "pushpin" symbols.  I have
      had repeated correspondence with the author (who only lives about
      8 miles from me) asking that standard APRS symbols be used to no
      avail.  He insists it isn't practical to import external symbols
      into MapPoint, which is strange considering that the UIpoint
      plug-in to use MapPoint with UIview does exactly this (use
      standard imported APRS symbols).

The alpha-numeric overlay character assignments (recently discussed on 
this list)  are even more of a problem.   The only Windows application 
that even renders overlay characters is UI-View.  

    * WinAPRS DOES NOT render overlays.
    * APRSpoint DOES NOT render overlays.
    * APRSplus DOES NOT render overlays.
    * The UIview plug-in for MapPoint DOES NOT render overlays.
    * APRS-CE (for Pocket PC) DOES NOT render overlays.
    * Pocket APRS (for Palm devices) DOES NOT render overlays.

Further, even the base symbol sets in WinAPRS, Pocket APRS and APRS/Ce 
are years out of date.  They cannot be updated (they are buried in the 
compiled .EXE file of these programs and inaccessible). 

To get UIview to render the new overlays in it's internally-displayed 
maps (i.e. not in external display plugins like UI-Point, UI-Route, 
etc),  will require revision of the _symbols.ini _file that is part of 
UI-View's symbol display mechanism.   This is an excerpt from 
symbols.ini for illustration.

REM                Primary Table                  Alternate Table
REM   Symbol   GPSxyz Index    Description     GPSxyz Index    Description
REM   ------   ------ -----    -----------     ------ -----    -----------
        !,      BB,     0,      Police Stn,     OB,     0,      Emergency
        ",      BC,     1,      No Symbol,      OC,     1,      No Symbol
        #,      BD,     2,      Digi,           OD,     2,      No. Digi
        $,      BE,     3,      Phone,          OE,     3,      Bank
        %,      BF,     4,      DX Cluster,     OF,     4,      No Symbol
        &,      BG,     5,      HF Gateway,     OG,     5,      No. Diam'd

[I update this file as part of new symbol set introductions.  The 
overlayable symbols requires placing "No. " in front of the symbol label 
as in "Digi" and "HF Gateway" above.  Note that "No" without the period, 
as in "No Symbol", denotes an unassigned slot.  "No." WITH the period 
and following space denotes an active symbol slot that is overlayable. 
Further, note that the entire Description field is limited to about 10 
characters due to a un-changeable  parser inside UIview. Placing the 
"No. " prefix on a symbol description, limits the label that shows in 
the selection dialog to only 6 characters ]

Finally, Bear in mind that any symbol must fit in a 16x16 pixel grid and 
not be rendered illegible by overlay symbols.  


Stephen H. Smith    wa8lmf (at) aol.com
EchoLink Node:      14400    [Think bottom of the 2M band]
Home Page:          http://wa8lmf.com  --OR--   http://wa8lmf.net

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