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READSB(1) User Commands READSB(1)

NAME

readsb - manual page for readsb version: 3.16 compiled on 250902

SYNOPSIS

readsb [OPTIONS...]

DESCRIPTION

readsb Mode-S/ADSB/TIS Receiver Build options: ENABLE_RTLSDR ENABLE_BLADERF ENABLE_PLUTOSDR ENABLE_SOAPYSDR

General options:

Reference/receiver surface latitude
Reference/receiver surface longitude
Disable interactive mode, print to stdout
Remove from list if idle for <sec> (default: 60)
Enable decoding of SSR Modes 3/A & 3/C
Enable Mode A/C if requested by a Beast connection
Absolute maximum range for position decoding (in nm, default: 300)
Enable CRC single-bit error correction (default)
Disable CRC single-bit error correction
Disable CRC single-bit error correction on the DF type to produce more DF17 messages (disabling reduces CPU usage)
Use metric units
Show only messages by given ICAO on stdout
Process only messages by given ICAO
When displaying decoded ModeS messages on stdout only show this DF type
Select SDR type (this needs to be placed on the command line before any SDR type specific options)
Set gain (default: auto gain, possible values for rtl-sdr devices: auto auto-verbose 0.0 0.9 1.4 2.7 3.7 7.7 8.7 12.5 14.4 15.7 16.6 19.7 20.7 22.9 25.4 28.0 29.7 32.8 33.8 36.4 37.2 38.6 40.2 42.1 43.4 43.9 44.5 48.0 49.6 58)
Set frequency (default: 1090 MHz)
Interactive mode refreshing data on screen. Implies --throttle
Show only messages hex values
lower threshold --> more CPU usage (default: 58, pi zero / pi 1: 75, hot CPU 42)
Forward received beast mlat results to beast output ports
Forward received mlat results to sbs output ports
Print stats at exit. No other output
Collect/show range histogram
Show and reset stats every <sec> seconds (rounded to the nearest 10 seconds due to implementation, first inteval can be up to 5 seconds shorter)
Run for X seconds, then exit (default: run indefinitely)
Make the range outline retain data for the last X hours (float, default: 24.0)
Show only ICAO addresses
Show altitudes as GNSS when available
Strip IQ file removing samples < level
Debug mode (verbose), n: network, P: CPR, S: speed check
Development debugging mode, see source for options, can be specified more than once
only process messages from receiverId
show CPR details for this hex
show leg marking details for this hex
show traceAdd details for this hex
Disable output (default)
Periodically write json output to <dir>
Periodically write prometheus output to <file>
Write traces to this directory, 1 gz compressed json per day and airframe
Write state to disk to have traces after a restart
Continuously write state to disk every X seconds (default: 3600)
Don't continuously update state.
Change the directory where heatmaps are saved (default is in globe history dir)
Make Heatmap, each aircraft at most every interval seconds (creates historydir/heatmap.bin and exit after that)
Dump compressed beast files to this directory, start a new file evey interval seconds
Write json output and update API json every sec seconds (default 1)
Accuracy of receiver location: 0: no location / internal use only, 1: 2 decimals, 2: exact (default), 3: 1 decimals, 4: 0 decimals
Main hash map size: 2^n entries (default: AIRCRAFT_HASH_BITS)
Write specially indexed globe_xxxx.json files (for tar1090)
Write receivers.json
Interval after which a new position will guaranteed to be written to the trace and the json position output (default: 30)
Don't write recent(1), full(2), either(3) traces to /run, only archive via write-globe-history (8: irregularly write limited traces to run, subject to change)
when using globe-index, write full traces to this directory instead of --write-json dir (typically /run/readsb), this can be used to reduce memory usage at the cost of roughly 100 IOPS for global traffic
Write aircraft.json also as aircraft.json.gz
Use only binary binCraft format for globe files (1), for aircraft.json as well (2)
write old gzipped binCraft files
Minimum position reliability to put it into json (default: 1, globe options will default set this to 2, disable speed filter: -1, max: 4)
Position persistence against outliers (default: 4), incremented by json-reliable minus 1
How long in minutes JAERO positions remain valid and on the map in tar1090 (default:33)
Default: "none" (as of writing a compatible file is available here: https://github.com/wiedehopf/tar1090-db/tree/csv)
aircraft.json: add long type as field desc, add field ownOp for the owner, add field year

Network options:

Establish connection, can be specified multiple times (e.g. 127.0.0.1,23004,beast_out) Protocols: beast_out, beast_in, raw_out, raw_in, sbs_in, sbs_in_jaero, sbs_out, sbs_out_jaero, vrs_out, json_out, gpsd_in, uat_in, uat_replay_out, planefinder_in, asterix_in, asterix_out (one failover ip/address,port can be specified: primary-address,primary-port,protocol,failover-address,failover-port) (any position in the comma separated list can also be either silent_fail or uuid=<uuid>)
Enable networking
Legacy Option, Enable networking, use --net instead
IP address to bind to (default: Any; Use 127.0.0.1 for private)
TCP Beast output listen ports (default: 0)
TCP Beast input listen ports (default: 0)
TCP raw output listen ports (default: 0)
TCP raw input listen ports (default: 0)
UAT replay output listen ports (default: 0)
UAT input listen ports (default: 0)
TCP BaseStation output listen ports (default: 0)
TCP BaseStation input listen ports (default: 0)
TCP SBS Jaero output listen ports (default: 0)
TCP SBS Jaero input listen ports (default: 0)
TCP Asterix output listen ports (default: 0)
TCP Asterix input listen ports (default: 0)
Apply beast reduce logic and interval to ASTERIX outputs
TCP VRS json output listen ports (default: 0)
TCP VRS json output interval (default: 5.0)
TCP json position output listen ports, sends one line with a json object containing aircraft details for every position received (default: 0) (consider raising --net-ro-size to 8192 for less fragmentation if this is a concern)
Set minimum interval between outputs per aircraft for TCP json output, default: 0.0 (every position)
TCP json position output: include aircraft without position (state is sent for aircraft for every DF11 with CRC if the aircraft hasn't sent a position in the last 10 seconds and interval allowing)
TCP API listen port (in contrast to other listeners, only a single port is allowed) (update frequency controlled by write-json-every parameter) (default: 0)
Shutdown delay to server remaining API queries, new queries get a 503 response (default: 0)
when running with globe-index, signal tar1090 use the readsb API to get data, requires webserver mapping of /tar1090/re-api to proxy_pass the requests to the --net-api-port, see nginx-readsb-api.conf in the tar1090 repository for details
TCP BeastReduce output listen ports (default: 0)
BeastReduce data update interval, longer means less data (default: 0.250, valid range: 0.000 - 14.999)
BeastReduce output: keep all messages relevant to mlat-client
beast-reduce: remove aircraft which are further than distance from the receiver
beast-reduce: remove aircraft which are above altitude
Apply beast reduce logic and interval to SBS outputs
forward receiver ID
primary ingest node
timeout receivers, output messages from timed out receivers as beast on <ports>
Number of decode threads, either 1 or 2 (default: 1). Only use 2 when you have beast traffic > 200 MBit/s, expect 1.4x speedup for 2x CPU
path to UUID file
TCP output flush size (maximum amount of internally buffered data before writing to network) (default: 1280)
TCP output flush interval in seconds (maximum delay between placing data in the output buffer and sending)(default: 0.05, valid values 0.0 - 1.0)
TCP output flush interval in seconds for beast-reduce outputs (default: value from --net-ro-interval, valid values 0.0 - 1.0)
Outbound re-connection delay (default: 15)
TCP heartbeat rate in seconds (default: 60 sec; 0 to disable)
control some buffer sizes: 8KB * (2^n) (default: n=1, 16KB)
Forward messages unchanged
SDR buffer / USB transfer size in kibibytes (default: 256 which is equivalent to around 54 ms using rtl-sdr, option might be ignored in future versions)

RTL-SDR options:

use with --device-type rtlsdr

Select device by index or serial number
Enable digital AGC (not tuner AGC!)
Set oscillator frequency correction in PPM

BladeRF options:

use with --device-type bladerf

Select device by bladeRF 'device identifier'
Use alternative FPGA bitstream ('' to disable FPGA load)
Assume FPGA decimates by a factor of N
Set LPF bandwidth ('bypass' to bypass the LPF)

HackRF options:

use with --device-type hackrf

Select device by serial number
Enable amp gain (RF stage) (~11 dB) (default: disabled)
Set gain (baseband stage) (default: 48, valid: 0-62, 2 dB steps)

Modes-S Beast options, use with --device-type modesbeast:

Path to Beast serial device (default /dev/ttyUSB0)
Turn ON DF11/17-only filter
Turn OFF MLAT time stamps
Turn OFF CRC checking
Turn ON DF0/4/5 filter
Turn OFF forward error correction
Turn ON mode A/C
Override Baudrate (default rate 3000000 baud, try 1000000 / 921600 as alternatives)

GNS HULC options, use with --device-type gnshulc:

Beast binary and HULC protocol input with hardware handshake enabled.

Path to GNS HULC serial device (default /dev/ttyUSB0)

ifile-specific options, use with --device-type ifile:

Read samples from given file ('-' for stdin)
Set sample format (UC8, SC16, SC16Q11)
Process samples at the original capture speed

ADALM-Pluto SDR options:

use with --device-type plutosdr

Create USB context from this URI.(eg. usb:1.2.5)
Hostname or IP to create networks context. (default pluto.local)

SoapySDR options:

use with --device-type soapysdr

Select device by SoapySDR key pair (ex. driver=lime)
Select an antenna
Select bandwidth
enable AGC
set SoapySDR gain element

Help options:

Give this help list
Give a short usage message

Credits: antirez (original dump1090) Malcom Robb (work on his dump1090 fork) mutability (forked to dump1090-mutability and further to dump1090-fa) Mictronics (readsb as a fork of dump1090-fa) wiedehopf (this fork of Mictronics readsb)

REPORTING BUGS

Report bugs to Matthias Wirth <matthias.wirth@gmail.com>

September 2025 readsb version: 3.16 compiled on 250902