WA8LMF Mirror of WB4APR Website - 21 July 2008 APRS SPEC 1.2

APRS SPEC draft Addendum 1.2

APRS 1.2 DRAFT SPEC ADDENDUM: The APRS 1.1 ADDENDUM was completed in July 2004. . This page now moves on to future addendum for APRS1.2. . But first we will list as a reminder all of those items that have already been included in 1.1:

  • A baseline of APRS usage as defined through July 2004.
  • Up-to-date SYMBOL tables, symbol attributes, and selection criteria for Just mobiles and Just WX
  • Up-to-date TO-CALLS, Version ID's and Experimental Formats
  • DIGI standards for Overlay Characters, Default Paths, the use of NOID and HID and SSID Conventions
  • Notes on DATUMs, map Range Scales, and PHG display, and packet time stamps
  • Message details on the Reply-ACK Algorithm, and Polygon and Line OBJECTS
  • notes on OBJECTS including punctuation, ownership, killing and equality with stations
  • Formats no longer recommended: Compressed-Objects, ITEM Format, Raw Weather Formats,
  • A link to the WXSVR Protocols and some small details on the APRS-Internet system

    New-N Paradigm: . There were also some recommendations for the good of the APRS national channel with respect to Digipeater ID rates, HF freqs and TNC offsets, Voice-Alert, and Recommended DIGI paths and settings. . These improvements were noted collectively as the New-N Paradigm and have made dramatic improvements throughout the APRS network.

    SPEC 1.2 ISSUES: This web page documents the ideas that have been proposed for further discussion and eventual addoption as APRS SPEC Addendum 1.2:

  • Mic-E TYPE Codes for distinguishing different capabilities
  • April 2007 SYMBOL Set Expansion Proposal. . New Overlay tables.
  • Operator Present BIT: An overlay O character indicates a manned station.
  • PRIORITY BIT: The E/W byte can be a priority bit. CAPS means priority, Lower case means routine. But again, UIview is case sensitive and would not work. WIth the priority bit, smart-digis can cut back on routine traffic during overloads.
  • APRS-IS Core and Tier-2 servers web pages (though an APRS-IS spec still does not exist).
  • Bar-Code Formats for APRS
  • SkyCommand additions to APRS
  • Emergency Codes for non-Mic-E systems
  • Water Gauge symbol and report formats.
  • Adding Parseable Frequency information into position and object comment fields.
  • Permanent Objects
  • Displaying a Circle or other attribute around any IGate station that sends an IGATE Status packet. (independent of symbol)
  • Proportional Pathing for mobiles - higher rate direct, lower rate via 1 and 2 hops
  • Fully supporting the New N Paradigm To obsolete the old dupe generating paths and encouraging WIDEn-N and SSn-N paths.
  • Network Stewardship Issues. Protecting the National Channel and facilitating good operating practices.
  • Higher precision !DAO! & datum format with precision to 1 ft with included datum. (Optional)
  • New Digipeater Object Caching concept. (optional)
  • Manual Table Position reporting with the TH-D7 (without a GPS).(Optional)
  • Omni-DF-ing techniques needing no DF equipment or antenna.
  • Probes: See the new PHGR concept addition to PHG for realtime measuring of Network Reliability.
  • MileMarks for voice reporting into APRS. Description, and Basic code, and mm-data.dat file.
  • SMART DIGI concepts.
  • APRS Message Entry techniques.
  • Japanese APRS: APRS JGates for linking the Japanese NAVITRA system with APRS .
  • ECHOlink & IRLP node status on APRS
  • The EYEBALL ICON if it has a RNGXXX descriptor will cause everyone's map (if the feature is enabled) to CENTER and ZOOM to range RNGxxxx on first receipt.


    APRS SPEC 1.3 proposals:

  • New APRS Areas evolving in HAM radio that involve APRS.


    The remainder of this stuff I am still working on. It needs to be incorporated into either 1.1, 1.2 or 1.3. I haven't cleaned it up recently. FOr now, I just leave it here until I can get back to it...

    Omni-DF: These comments were received as feedback on the DF part of the spec:

  • Formula for sizing is not specified in spec.
  • Colors of circles are not specified.
  • DFSxxxx has slash after it? Not specified in spec.
  • DFSxxxx/ has speed/course after it? Not that way in spec.
  • Where the spec describes objects/items, it doesn't allow for /BRG/NRQ. Refer to page 97. In other places where it talks about /BRG/NRQ it specifically shows them as a possible option in the format.
  • The spec shows that DFS and /BRG/NRQ can exist in the same packets, which is most likely wrong. The spec should be revised.
  • In the spec it shows that you can have DFS or Course/Speed, but not both at the same time. In your example packets (from DOSaprs) you have both, with DFS coming first. Which one is correct? One or the other should be revised so that they agree.
  • Bob handled the divide-by-zero error by changing the 0 level signal to 0.8. Not in spec or on Bob's web pages.

    OMNI-DF: To see what the OMNI-DF screen (based inversly on PHG)looks like, see: Bob's DFing WEB page

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    The Naval Academy is a registered user of APRS and WinAPRS. The purpose of this web page is to show several applications currently in use at this site and should not be considered as an advertisement or an endorsement of any commercial product. WA8LMF Mirror of WB4APR Website - 21 July 2008