Appendix 1: APRS Data Formats¶

This Appendix contains format diagrams for all APRS data formats. The gray fields are optional. Shaded (yellow) characters are literal ASCII characters.

*AX.25 UI-FRAME FORMAT*
*Flag*	*Destination Address*	*Source Address*	*Digipeater Addresses (0-8)*	*Control Field (UI)*	*Protocol ID*	*INFORMATION FIELD*	*FCS*	*Flag*
1	7	7	0–56	1	1	1–256	2	2

Bytes:

*Generic APRS Information Field*
*Data Type ID*	*APRS Data*	*APRS Data Extension*	*Comment*
1	n	7	n

Bytes:

*Lat/Long Position Report Format — without Timestamp*
! or =	*Lat*	*Sym Table ID*	*Long*	*Symbol Code*	*Comment (max 43 chars)*
1	8	1	9	1	0-43

Bytes:

*Lat/Long Position Report Format — with Timestamp*
/ or @	*Time DHM / HMS*	*Lat*	*Sym Table ID*	*Long*	*Symbol Code*	*Comment (max 43 chars)*
1	7	8	1	9	1	0-43

Bytes:

*Lat/Long Position Report Format — with Data Extension (no Timestamp)*
! or =	*Lat*	*Sym Table ID*	*Long*	*Symbol Code*	*Course/Speed*	*Comment (max 36 chars)*
*Power/Height/Gain/Dir*
*Radio Range*
*DF Signal Strength*
1	8	1	9	1	7	0-36

Bytes:

*Lat/Long Position Report Format — with Data Extension and Timestamp*
/ or @	*Time DHM / HMS*	*Lat*	*Sym Table ID*	*Long*	*Symbol Code*	*Course/Speed*	*Comment (max 36 chars)*
*Power/Height/Gain/Dir*
*Radio Range*
*DF Signal Strength*
1	7	8	1	9	1	7	0-36

*Maidenhead Locator Beacon*
[	*Grid Locator*	]	*Comment*
1	4 or 6	1	n

Bytes:

*Raw NMEA Position Report Format*
*NMEA Received Sentence*
$	…,…,…,…,…,…,…,…,…,…
1	25-209

Bytes:

*DF Report Format — without Timestamp*
! or =	*Lat*	*Sym Table ID* /	*Long*	*Symbol Code* **	*Course/Speed*	/BRG/NRQ	*Comment (max 28 chars)*
*Power/Height/Gain/Dir*
*Radio Range*
*DF Signal Strength*
1	8	1	9	1	7	8	0-28

Bytes:

*DF Report Format — with Timestamp*
/ or @	*Time DHM / HMS*	*Lat*	*Sym Table ID* /	*Long*	*Symbol Code* **	*Course/Speed*	/BRG/NRQ	*Comment (max 28 chars)*
*Power/Height/Gain/Dir*
*Radio Range*
*DF Signal Strength*
1	7	8	1	9	1	7	8	0-28

Bytes:

*Compressed Lat/Long Position Report Format — no Timestamp*
! or =	*Sym Table ID*	*Comp Lat* YYYY	*Comp Long* XXXX	*Symbol Code*	*Compressed Course/Speed*	*Comp Type* T	*Comment (max 40 chars)*
*Compressed Radio Range*
*Compressed Altitude*
1	1	4	4	1	2	1	0-40

Bytes:

*Compressed Lat/Long Position Report Format — with Timestamp*
/ or @	*Time DHM / HMS*	*Sym Table ID*	*Comp Lat* YYYY	*Comp Long* XXXX	*Symbol Code*	*Compressed Course/Speed*	*Comp Type* T	*Comment (max 40 chars)*
*Compressed Radio Range*
*Compressed Altitude*
1	7	1	4	4	1	2	1	0-40

Bit:

Value:

*Compression Type (T) Byte Format*
7	6	5	4	3	2	1	0
Not used	Not used	*GPS Fix*	*NMEA Source*		*Compression Origin*
0	0	0 = old (last)	0 0 = other		0 0 0 = Compressed
		1 = current	0 1 = GLL		0 0 1 = TNC BText
			1 0 = GGA		0 1 0 = Software (DOS/Mac/Win/+SA)
			1 1 = RMC		0 1 1 = [tbd]
					1 0 0 = KPC3
					1 0 1 = Pico
					1 1 0 = Other tracker [tbd]
					1 1 1 = Digipeater conversion

*Mic-E Data — DESTINATION ADDRESS FIELD Format*
*Lat Digit 1* *+ Message Bit A*	*Lat Digit 2* *+ Message Bit B*	*Lat Digit 3* *+ Message Bit C*	*Lat Digit 4* *+ N/S Lat Indicator*	*Lat Digit 5* *+ Longitude Offset*	*Lat Digit 6* *+ W/E Long Indicator*	*APRS* *Digi Path Code*
1	1	1	1	1	1	1

*Mic-E Data — INFORMATION FIELD Format*
*Data Type ID*	*Longitude*			*Speed and Course*			*Symbol Code*	*Sym Table ID*	*Mic-E Telemetry Data (obsolete)*
d+28	m+28	h+28	SP+28	DC+28	SE+28	*Mic-E Status Text*
1	1	1	1	1	1	1	1	1	n

Bytes:

*Object Report Format — with Lat/Long position*
;	*Object Name*	* or _	*Time DHM / HMS*	*Lat*	*Sym Table ID*	*Long*	*Symbol Code*	*Course/Speed*	*Comment (max 36 chars with Data Extension, or* *43 without)*
*Power/Height/Gain/Dir*
*Radio Range*
*DF Signal Strength*
*Area Object*
1	9	1	7	8	1	9	1	7	0-36/43

*Object Report Format — with Compressed Lat/Long position*
;	*Object Name*	* or _	*Time DHM / HMS*	*Compressed Position Data* /YYYYXXXX$csT	*Comment*
1	9	1	7	13	43

Bytes:

*Item Report Format — with Lat/Long position*
)	*Item Name*	! or _	*Lat*	*Sym Table ID*	*Long*	*Symbol Code*	*Course/Speed*	*Comment* *(max 36 chars with Data Extension, or 43 without)*
*Power/Height/Gain/Dir*
*Radio Range*
*DF Signal Strength*
*Area Object*
1	3-9	1	8	1	9	1	7	0-36/43

Bytes:

*Item Report Format — with Compressed Lat/Long position*
)	*Item Name*	! or _	*Compressed Position Data* /YYYYXXXX$csT	*Comment*
1	3-9	1	13	43

Bytes:

*Raw Weather Report Format - Not Recommended - Use Complete Weather Report Format*
! or # or $ or *	*Raw Weather Data*
1	n

Bytes:

*Positionless Weather Report Format - Not Recommended - Should use Complete Weather Report*
_	*Time MDHM*	*Weather Data*	*APRS* *Software* S	WX *Unit* uuuu
1	8	n	1	2-4

*Weather Data*
Wind Direction cccc	Wind Speed ssss	*Gust* gggg	*Temp* tttt	Rain Last Hr rrrr	*Rain Last 24 Hrs* pppp	*Rain Since Midnight* PPPP	*Humidity* hhh	Barometric Pressure bbbbbb
4	4	4	4	4	4	4	3	6

Bytes:

*Complete Weather Report Format — with Lat/Long position, no Timestamp*
! or =	*Lat*	*Sym Table ID*	*Long*	*Symbol Code* _	*Wind Directn/ Speed*	*Weather Data*	*APRS* *Software* S	WX *Unit* uuuu
1	8	1	9	1	7	n	1	2-4

Bytes:

*Complete Weather Report Format — with Lat/Long position and Timestamp*
/ or @	*Time DHM / HMS*	*Lat*	*Sym Table ID*	*Long*	*Symbol Code* _	*Wind Directn/ Speed*	*Weather Data*	*APRS* *Software* S	WX *Unit* uuuu
1	7	8	1	9	1	7	n	1	2-4

Bytes:

*Complete Weather Report Format — with Compressed Lat/Long position, no Timestamp*
! or =	*Sym Table ID*	*Comp Lat* YYYY	*Comp Long* XXXX	*Symbol Code* _	*Comp Wind Directn/ Speed*	*Comp Type* T	*Weather Data*	*APRS* *Software* S	WX *Unit* uuuu
1	1	4	4	1	2	1	n	1	2-4

Bytes:

*Complete Weather Report Format — with Compressed Lat/Long position, with Timestamp*
/ or @	*Time DHM / HMS*	*Sym Table ID*	*Comp Lat* YYYY	*Comp Long* XXXX	*Symbol Code* _	*Comp Wind Directn/ Speed*	*Comp Type* T	*Weather Data*	*APRS* *Software* S	WX *Unit* uuuu
1	7	1	4	4	1	2	1	n	1	2-4

Bytes:

*Complete Weather Report Format — with Object and Lat/Long position*
*	*Object Name*	*	*Time DHM / HMS*	*Lat*	*Sym Table ID*	*Long*	*Symbol Code* _	*Wind Directn/ Speed*	*Weather Data*	*APRS* *Software* S	WX *Unit* uuuu
1	9	1	7	8	1	9	1	7	n	1	2-4

Bytes:

*Telemetry Report Format*
T	Sequence No #nnn,	*Analog Value 1* aaa,	*Analog Value 2* aaa,	*Analog Value 3* aaa,	*Analog Value 4* aaa,	*Analog Value 5* aaa,	*Digital Value* bbbbbbbb	*Comment*
1	5	4	4	4	4	4	8	n

Note: Most modern applications recognize variable length fields with decimal points and leading minus sign.

Bytes:

*Storm Data*
*Direction*	/	*Speed*	*Storm Type* /ST	*Sustained Wind Speed* /www	*Peak Wind Gusts* ^GGG	*Central Pressure* /pppp	*Radius Hurricane Winds* >RRR	Radius Tropical Storm Winds &rrr	*Radius Whole Gale* %ggg
3	1	3	3	4	4	5	4	4	4

*Telemetry Parameter Name Message Data* Note the different byte counts, which include commas where shown. The list may stop at any field.
PARM.	A1 N…	A2 ,N…	A3 ,N…	A4 ,N…	A5 ,N…	B1 ,N…	B2 ,N…	B3 ,N…	B4 ,N…	B5 ,N…	B6 ,N…	B7 ,N…	B8 ,N…
5	1-7	1-7	1-6	1-6	1-5	1-6	1-5	1-4	1-4	1-4	1-3	1-3	1-3

Bytes:

*Message Rejection Format*
:	*Addressee*	:	rej	*Message No* xxxxx
1	9	1	3	1–5

Bytes:

*Telemetry Unit/Label Message Data* Note the different byte counts, which include commas where shown. The list may stop at any field.
UNIT.	A1 U…	A2 ,U…	A3 ,U…	A4 ,U…	A5 ,U…	B1 ,L…	B2 ,L…	B3 ,L…	B4 ,L…	B5 ,L…	B6 ,L…	B7 ,L…	B8 ,L…
5	1-7	1-7	1-6	1-6	1-5	1-6	1-5	1-4	1-4	1-4	1-3	1-3	1-3

*Telemetry Equation Coefficients Message Data* The list may stop at any field. Value = a x v2 + b x v + c
EQNS.	A1			A2			A3			A4			A5
a	,b	,c	,a	,b	,c	,a	,b	,c	,a	,b	,c	,a	,b	,c
5	n	n	n	n	n	n	n	n	n	n	n	n	n	n	n

*Telemetry Bit Sense/Project Name Message Data*
BITS.	B1 x	B2 x	B3 x	B4 x	B5 x	B6 x	B7 x	B8 x	*Project Title*
5	1	1	1	1	1	1	1	1	0-23

Bytes:

*Message Format*
:	*Addressee*	:	*Message Text (max 67 chars)*	*Message ID*
{	*Message No* xxxxx
1	9	1	0-67	1	1-5

*Message Acknowledgement Format*
:	*Addressee*	:	ack	*Message No* xxxxx
1	9	1	3	1–5

Bytes:

*General Bulletin Format*
:	BLN	*Bulletin ID* n	˽˽˽˽˽	:	*Bulletin Text (max 67 characters)*
1	3	1	5	1	0-67

*Announcement Format*
:	BLN	*Announcement Identifier* x	˽˽˽˽˽	:	*Announcement Text (max 67 characters)*
1	3	1	5	1	0-67

Bytes:

*Group Bulletin Format*
:	BLN	*Group Bulletin ID* n	*Group Name*	:	*Group Bulletin Text (max 67 characters)*
1	3	1	5	1	0-67

Bytes:

*National Weather Service Bulletin Format*
:	NWS-xxxxx	:	*NWS Bulletin Text*
1	9	1	n

Bytes:

*General Query Format*
?	*Query Type*	?	*Target Footprint*
*Lat*	,	*Long*	,	*Radius*
1	n	1	n	1	n	1	4

Bytes:

*Directed Station Query Format*
:	*Addressee*	:	?	*Query Type*	*Callsign of Heard Station*
1	9	1	1	5	0-9

Bytes:

*Status Report Format*
>	*Time DHM z*	*Status Text* *(max 62 chars if no timestamp, or 55 chars if there is a timestamp)*
1	7	0-62 or 0-55

*Status Report Format — with Maidenhead Grid Locator*
>	*Maidenhead Locator*			*Sym Table ID*	*Symbol Code*	*Status Text (starting with a space)* ˽ *(max 54 chars)*
GG	nn	gg
1	2	2	2	1	1	1-54

Bytes:

*Data with Source Path Header*
*Source Path Header*	*Data Type ID*	*Rest of the original data*
n	1	n

*Source Path Header — “TNC-2” Format* An asterisk follows the digipeater callsign heard.
Source Callsign (-SSID)	>	*Destination Callsign* (-SSID)	*0-8 Digipeaters*	:
,	*Digipeater Callsign* (-SSID)(*)
1-9	1	1-9	0-80	1

Bytes:

*Source Path Header — “AEA” Format* *Obsolete - shown for historical reference only.* An asterisk follows the source or digipeater callsign heard.
*Source Callsign* (-SSID)(*)	*0-8 Digipeaters*	>	*Destination Callsign* (-SSID)	:
>	*Digipeater Callsign* (-SSID)(*)
1-10	0-80	1	1-9	1

Bytes:

*Agrelo Format*
%	*Bearing* nnn	/	*Quality* n
1	3	1	1

Bytes:

*Third-party Format*
}	*Third-Party Header*	*Rest of the original data*
1	n	n

*Third Party Header — “TNC-2” format*
*Source Path Header* *(without “unused” digipeaters,* * or :)**	,	*Third-Party Network Identifier (“callsign”)*	,	Callsign of Receiving Gateway Station (-SSID)	*	:
n	1	1-9	1	1-9	1	1

*Third Party Header — “AEA” format* *Obsolete - Shown for historical reference only.*
*Source Path Header* (without “unused” digipeaters, destination, * or :)	*Third-Party Network Identifier (“callsign”)*	>	Callsign of Receiving Gateway Station (-SSID)	*	>	*Destination Callsign from Source Path Header* (-SSID)	:
2-90	1-9	1	1-9	1	1	1-9	1

Bytes:

*User-Defined Data Format*
{	*User ID* U	*User-Defined Packet Type* X	*User-defined data (printable ASCII recommended)*
1	1	1	n

*Invalid Data / Test Data Format*
,	*Invalid Data or Test Data*
1	n