Radarcape:Software Features

Radarcape/Air!Squitter Software Features

The Radarcape provides output of data in several levels:

• true raw data
• decoded data on a per frame basis (e.g., port 30003)
• decoded data on summary basis (e.g., aircraftlist.json, deltadb.txt)
• web browser support (aircraft list, 2D map)
• 3D output (live KML data)

Web Based Aircraft Table

A list of received aircraft can be fetched via a build-in Web server. This list can be sorted ascending and descending in each column by simply clicking on the arrows. The distances are automatically calculated from aircraft positions and your GPS coordinates.

Radarcape Live Aircraft Table

Name	Description	Notes
Time (hh:mm:ss:ns)	Time of last message received from the aircraft
ICAO	24 bit ICAO hex ID unique identification of aircraft
Flight	the Call Sign as it is transmitted from the aircraft itself
Lon	Longitude
Lat	Latitude
Src	Source of Lat/Lon: A=ADSB M=MLAT
GndAir	Aircraft is on ground (identified with GND bit or DF-18 messages) or airborne
Alt	Altitude (feet) at 1013 mb
VRate	Vertical rate in feet/min
Speed	Ground Speed in knots
Track	Direction that the aircraft is travelling in degrees true
Cat	Cat A0..C5 are transmitted by aircraft in Mode-S messages
Orig	Origin of flight	taken from database, perform Maintenance -> Update flight routes database
Destin	Destination of flight	taken from database, perform Maintenance -> Update flight routes database
Oper	Flight operator	taken from database, perform Maintenance -> Update flight routes database
Type	Aircraft Type	taken from database, perform Maintenance -> Update flight routes database
Reg	Registration of aircraft	taken from database, perform Maintenance -> Update base station database
Squawk	Squawk code as it is transmitted by aircraft in Mode-S messages
Country	Country that the aircraft is registered for, indicated through the upper bits in the ICAO hex id
Distance	Distance to the observer if its Lat, Lon is either valid by manual entry in configuration or determined by GPS
Trust	Number of highly trustable DF-11 or DF-17/18 messages per aircraft. Used to desinguish ghosts, as true aircraft quickly raise this number while ghosts stay at 1
Track Size	Length of the track in 2D 3D display in 5sec sequence track points

Live 2D Output

All received aircrafts with a known position are displayed on a 2D map in your Web browser.

Radarcape Live 2D Display

Live 3D Output (KML/KMZ Output)

Google Earth can be attached to the Radarcape via KML/KMZ files.

Google Earth with live ADS-B data
An aircraft over Augsburg Airport

A go around in Munich EDDM

DeltaDB Service

The DeltaDB service can be accessed via http://radarcape/deltadb.txt. It outputs a comma separated list of all changes in the internal aircraft list since the last call or a specified time. This is an efficient replacement of port 30003 functionalities.

Aircraft List JSON Service

All data contained in the aircraft list can also be downloaded in JavaScript Object Notation (JSON). The file format can be used by other applications to access aircraft list data using the Hyper Text Transfer Protocol (HTTP) protocol.

The Aircraftlist JSON Service can be accessed via http://radarcape/aircraftlist.json.

The JSON output uses abbreviated identifiers for the data fields like below.

Note: Fields for which no data have been received might either be absent from the JSON, or set to "null". You should not expect all fields to be always available

With some additional parameters that are described in the Software Features Major 2 the list can be filtered on the server side saving some amount of data to be transferred.

Abbreviation	Description	Minimum required ADS-B version (MOPS)	Value Origin	Additional Information
uti	Time of last message: Seconds since UNIX epoch		Clock
ns	Time of last message: Nanoseconds since Second epoch		Clock
hex	ICAO Mode-S or Flarm ID, in Hex format		Mode-S or FLARM
fli	Flight Identification		Mode-S	From ADS-B or BDS2,0 as specified on ICAO Annex 10, Volume IV, Table 3-9; "?" when A/C reports loss of interface
ava	Flight data: available flight data sources			One letter per available flight data sources. A=ADSB, M=Jetvision MLAT, F=FlightAware MLAT, O=OGN, L=FLARM
src	Flight data: Source			The current preferred/selected flight data source (i.o.w. for <lat>, <lon>, <alt>, <spd>, <trk> and <vrt>)
cla	ADS-B Classification		Receive Channel & ADS-B	Subclass of ADS-B data
lat	Flight data: Latitude (-90 to 90º)		<src>
lon	Flight data: Longitude (-180 to 180º)		<src>
alt	Flight data: Barometric uncalibrated altitude (ft)		<src>
spd	Flight data: Ground Speed (kt)		<src>
trk	Flight data: True track (0-360º)		<src>
vrt	Flight data: Vertical Rate (ft/min)		<src>
gda	Airborne/Ground		Mode-S	G for on ground, A for airborne (if TIS-B then lowercase g or a)
cat	Aircraft category		Mode-S or FLARM	As reported in ADS-B or FLARM. See table below.
org	Origin		DB	Origin airport from Flighroutes database, derived from <fli>
dst	Destination		DB	Destination airport from Flighroutes database, derived from <fli>
opr	Operator		DB	Operator from Basestation database, derived from <hex>
typ	Type		DB	Type from Basestation database, derived from <hex>
reg	Registration		DB	Registration from Basestation database with respect to <fli> or if not available automatically deduced for some countries with known mapping (FR, BE, PT, CH, US and CA)
squ	Mode-A (Squawk)		Mode-S	While this is a Mode-A code, it can only be correlated in Mode-S targets. Mode-A or Mode-A/C targets are not displayed in decoded formats since they cannot be correlated with a <hex> value
cou	Country		<hex>	Country according to Mode-S allocation block if decodable, mostly unusable/invalid for FLARM A/C
dis	Distance (km or NM depending on configuration)			To the Receiver GNSS location
tru	Trust count			Number of Mode-S frames successfully decoded from this A/C. Statistically it's possible that for a very low count the A/C does not actually exist
dbm	Approximate signal level in dBm
lla	Age of last Position (s)		Clock
tmp	Temperature (ºC)	0	Mode-S	Synthetic value calculated from several fields. Might not be always reliable
wsp	Wind Speed (kt)	0	Mode-S	Synthetic value calculated from several fields. Might not be always reliable
wdi	Wind from Direction (0-360º)	0	Mode-S	Synthetic value calculated from several fields. Might not be always reliable
mop	ADS-B MOPS version		ADS-B	NULL=no ADS-B frames received, 0=default for unconfirmed version, 1 or 2 for corresponding confirmed version
spi	SPI (Squawk ident)		Mode-S
alr	Alert status		Mode-S	0=no alert, 1=temporary (Squawk changed previous 18s), 2=mode-s alert, 3=permanent (Squawk 7500,7600,7700). Since Mode-S DF4,5,20,21 do not distinguish between temporary and permanent alert, the value 2 is used to mean either 1 or 3 and happens for non ADS-B A/C targets
ias	IAS	0	Mode-S	Typically not reported by a fully operational A/C as by default only Ground speed and True track are transmitted
tas	TAS	0	Mode-S	Typically not reported by a fully operational A/C as by default only Ground speed and True track are transmitted
hdgm	Magnetic Heading	0	Mode-S	Typically not reported by a fully operational A/C as by default only Ground speed and True track are transmitted
hdgt	True Heading	0	Mode-S	Calculated with declination when Magnetic Heading and Location are available
qnhs	Selected QNH	2	Mode-S	Actual value entered by the A/C crew
alts	Selected Altitude	2	Mode-S	Actual value entered by the A/C crew
hdgs	Selected Heading	2	Mode-S	Actual value entered by the A/C crew
altg	GNSS elipsoidal altitude (ft)	0	Mode-S	Either directly reported or from baro+difference
pic	Asterix PIC	0	Mode-S	EUROCONTROL-SPEC-0149-12 (ASTERIX Cat 021 Ed 2.4) Page 28
tcm	ACAS/TCAS status	0, alert only 2	Mode-S	0=not operational, 1=operational, 2=alert
ape	Autopilot engaged	2	Mode-S
sil	ADS-B SIL	1	Mode-S
sda	ADS-B SDA	2	Mode-S
nacp	ADS-B NACp	1	Mode-S
pest	Number of position estimations per second		MLAT
nocl	Number of sensors providing data aircraft		MLAT
tq	Time quality of this entry		Sensor	0: GNSS 1: Sensor NTP 2: Server NTP

Value Origin	Description
<hex>	Derived from the ICAO ID or FLARM ID of the A/C
<src>	Value originates from the data source indicated in <src> field
DB	Value is read from database according to refrenced <hex> or <fli> value
Mode-S	Any Mode-S or ADS-B frame received from an A/C identified with <hex> field
FLARM	Any FLARM frame received from an A/C identified with FLARM ID equal to <hex> field

Data Source Identifiers

"src", "ava" field contents

src	Source	Frequency
A	ADS-B	1090 MHz + 978 MHz
M	Multilateration	1090 MHz
L	OGN Decoder	868 MHz
F	piAware	1090 MHz
O	OGN Server Connection	868 MHz
S	FLARM SkyLens FLARM	868 MHz
D	FLARM SkyLens ADS-L	868 MHz

ADS-B Data Subclasses

"cla" field contents

cla	Frequency	Shortcut	Source	Adress Type	Comment
0	1090 MHz	Mode-S	Transponder	ICAO
1		TISB_ModeA	TIS-B	Mode-A
2		TISB_Anonym	TIS-B	Anonymous
3		TISB_ICAO	TIS-B	ICAO
4		DF18_ADSR_ICAO	ADS-R	ICAO
5		DF18_ADSR_Anonym	ADS-R	Anonymous
6		DF18_NT_ICAO	Non transponder	ICAO	Obstacle or ground vehicle
7		DF18_NT_Anonym	Non transponder	Anonymous	Obstacle or ground vehicle
8	978 MHz (UAT)	UAT_ADSB_ICAO	Transponder	ICAO
9		UAT_ADSB_Temporary	Transponder	Temporary
10		UAT_TISB_ICAO	TIS-B	ICAO
11		UAT_TISB_TrackID	TIS-B	Track-ID
12		UAT_SurfaceVehicle	Surface vehicle	FAA specific
13		UAT_FixedADSBBeacon	Surface vehicle	FAA specific
14	ISM (FLARM)	FLARM	Transponder	ICAO or FLARM non overlapping assignment	FLARM only as soon as a Mode-S frame is received cla will change to 0

Aircraft categories

Code	Type	Description
A1	ADS-B	Light (< 15500 lbs)
A2	ADS-B	Small (15500 >= lbs < 75000)
A3	ADS-B	Large (75000 >= lbs < 300000)
A4	ADS-B	Large (high vortex)
A5	ADS-B	Heavy (>= 300000 lbs)
A6	ADS-B	High performance
A7	ADS-B	Rotorcraft
B1	ADS-B	Glider/Sailplane
B2	ADS-B	Lighter than air
B3	ADS-B	Parachutist/Skydiver
B4	ADS-B	Ultralight/Hang glider/Paraglider
B6	ADS-B	UAV
B7	ADS-B	Space/Trans-atmospheric vehicle
C1	ADS-B	Surface vehicle - emergency
C2	ADS-B	Surface vehicle - service
C3	ADS-B	Obstacle - point
C4	ADS-B	Obstacle - clustter
C5	ADS-B	Obstacle - line
A0	ADS-B	No category information
B0	ADS-B	No category information
C0	ADS-B	No category information
F0	FLARM	None
F1	FLARM	Glider/Motor glider
F2	FLARM	Tow/Tug plane
F3	FLARM	Helicopter/Rotorcraft
F4	FLARM	Skydiver
F5	FLARM	Skydiver/Drop plane
F6	FLARM	Hang glider
F7	FLARM	Paraglider
F8	FLARM	Aircraft reciprocating
F9	FLARM	Aircraft jet turboprop
F11	FLARM	Balloon
F12	FLARM	Airship
F13	FLARM	UAV
F15	FLARM	Static

Raw Data Streaming to Network (TCP and UDP)

The binary and AVR raw data formats are identical to those of the Mode-S Beast and documented in Mode-S_Beast:Data_Output_Formats. For the Radarcape, there is one additional message that contains timestamp and FPGA configuration information, which is triggered by each 1PPS from the GPS module.

TCP or UDP port 10002

This is a CRC-checked mirror of the data as it comes from the FPGA, DF-11, DF-17 and DF-18 are CRC checked if enabled in FPGA. Includes Mode-A/C data with respect to the configuration setting.

TCP or UDP port 10003

Binary formatted raw data with all Modes-S data formats CRC-prechecked (eliminates transmission of the erroneous frames, reduces load on the network). All data from the FPGA is disassembled into messages and verified if correct.

TCP or UDP port 10004

Binary formatted raw data, pre-checked DF-11, DF-17 and DF-18 only: minimum load for the transmission path but contains most information. No Mode-A/C data.

TCP or UDP port 10005

Binary formatted raw data, only raw data frames of those aircraft where the location (latitude and longitude) is unknown. Used for special MLAT purposes. No Mode-A/C data.

Port 30003 Service (TCP, UDP, and USB-serial)

Port 30003 style output (e.g., for use with SBS Plotter) can be provided without the need of an additional application on your PC.

The Radarcape provides this data stream on TCP port 30003, UDP port 30003, and the serial USB interface.

The format of the data output can be found in this document
The date in Port 30003 messages is always the Linux system date.
The timestamp instead is a GPS timestamp when the configuration is set to GPS timestamps and system time when the Radarcape operates in legacy 12 MHz time stamp mode.

Due to the low efficiency and high processor load caused by this protocol, please do not use Port 30003 unless really necessary.

A better way of getting the same data is the deltaDB service.

On Linux, a very simple method how to access the TCP stream of Port 30003 is socat:

socat - TCP:radarcape:80

Output of FLARM data on port 30003

Starting with version 210406.1000.02, there is an option to also output FLARM frames on port 30003.

This can be configured on the web interface via Settings -> UDP Data Streaming Settings -> Port 30003 UDP Server -> Output Flarm data on Port 30003.

By default, there will be no FLARM data output on port 30003.

If enabled, FLARM data can be output using one of two options:

• FLARM data will be output using a MSG,3 message, which will be indistinguishable from a MSG,3 message generated after reception of a Mode-S frame
• FLARM data will be output using a newly introduced MSG,9 message, which contains only data received via FLARM

MSG,9 output format

The output format of the MSG,9 message is a combination the MSG,3 and MSG,4 messages.

MSG,9 messages contain all of the following fields in addition to the first ten common fields: Altitude, Ground Speed, Track, Latitude, Longitude, Vertical Rate and IsOnGround.

These messages will only be generated if enabled in the settings menu and will only contain data received via a local FLARM receiver.

USB Serial Port Data Access

While some features existed before, this feature is more reliable on Debian 10 . See Linux Distribution Versions History.

The device supports one selectable data stream out of following sources on a virtual serial port via the back side USB port:

• Raw FGPA data - including Mode-A/C data
• CRC pre-checked Mode-S with Mode-A/C data
• Mode-S Frame types DF-11, DF-17 and DF-18 only
• Mode-S Frames of all aircraft without a known location
• Port 30003 format

The output can be selected in the configuration menu. Due to processor load, it is recommended to keep this feature disabled when not required.

The setting can be changed on the fly and will apply without the need to reboot the device.

Note: On the Radarcape of 1st Generation two serial ports appear on the USB interface. One of them is a hardware serial port for debug

Note: When powering on, the external +5 V power supply MUST be connected prior to connecting the USB cable

The serial port uses a standard USB class driver and should install automatically in any Operating System that is currently supported.