This is a section of the aprs.fi user guide.
The raw packets page allows you to browse and inspect APRS packets received from the APRS-IS. When you load the page initially (or click Clear) it will show the most recent APRS packets received. The previous and next buttons can be used to browse older ones. If you click on Raw packets in the real-time map while tracking a station, you will automatically get the packets sent by that station.
Invalid packets (and ones which are valid but which are not supported by aprs.fi) are shown in red, together with an English error message. Unprintable non-ASCII characters are displayed in hex with a purple colour. <0x1c> stands for a byte which has a hex value of 1C (28 decimal).
To see a hex dump of the complete packet contents (revealing difference in whitespace: tabs, amount of space characters in the end of the line), move the mode selector from Normal to Hex.
To view the decoded contents of the packets, switch to the Decoded mode. This will display what information the Ham::APRS::FAP APRS packet parser is able to find from the packets, and is very useful for understanding the contents of mic-e and compressed format packets. aprs.fi internally uses the open-source Ham::APRS::FAP parser for decoding.
If you are considering downloading raw or decoded packets from this page in an automated fashion, with wget/curl and a script or such, please take a look at the Terms of Service and API pages first. Thank you!
The beacons page shows packets received from the APRS-IS but which were not identified as APRS packets at all. They are typically identification beacons sent by network nodes, usually describing their hardware or software.
2010-07-02 03:44:07 UTC: DB0EMS>UIDIGI: UIDIGI 1.9 2010-07-02 03:44:38 UTC: DB0UAL>ID: DB0UAL * X-NET-DIGI * -9k6 Shift
aprs.fi user guide