FlightAware Discussions

Dump1090-fa options default values

Is there a way for me to have dump1090 spit out a list of the values its using for all of its options/parameters? In particular I’m interested in the values its using for its adaptive burst mode. I live near a large airport, which means I have a near/far issue with the close aircraft blinding me to planes further out. I’d like to try to fine tune the burst parameters to see if a faster adaptive response will help.

I can see the list of parameters using “dump1090-fa --help”, but not the default values.

You can find the config file which installs during setup on Github:

# dump1090-fa configuration
# This is sourced by /usr/share/dump1090-fa/start-dump1090-fa as a
# shellscript fragment.

# dump1090-fa won't automatically start unless ENABLED=yes
ENABLED=yes

# SDR device type. Use "none" for a net-only configuration
RECEIVER=rtlsdr
# serial number or device index of device to use (only needed if there is more than one SDR connected)
RECEIVER_SERIAL=
# Initial receiver gain, in dB. If adaptive gain is enabled (see below) the actual gain
# may change over time
RECEIVER_GAIN=60

# Adjust gain to try to achieve optimal dynamic range / noise floor?
ADAPTIVE_DYNAMIC_RANGE=yes
# Target dynamic range in dB (leave blank to autoselect based on SDR type)
ADAPTIVE_DYNAMIC_RANGE_TARGET=
# Reduce gain when loud message bursts from nearby aircraft are seen?
ADAPTIVE_BURST=no
# Gain range to allow when changing gain, in dB (empty = no limit)
ADAPTIVE_MIN_GAIN=
ADAPTIVE_MAX_GAIN=

# Turn on options to reduce load on slower CPUs, at the expense of slightly worse decoder performance.
# Setting "auto" will enable these options only if the CPU appears to be a slow CPU (currently this
# means armv6 only, e.g. Pi Zero)
SLOW_CPU=auto
# Local wisdom file used to select DSP implementations; uses built-in ranking if the file is missing
WISDOM=/etc/dump1090-fa/wisdom.local

# Correct CRC errors where possible
ERROR_CORRECTION=yes

# Receiver location, used for some types of position decoding. Provide the location as
# signed decimal degrees. If not given here, dump1090 will also try to read a receiver
# location from /var/cache/piaware/location.env (written automatically by PiAware, if installed)
RECEIVER_LAT=
RECEIVER_LON=
# Maximum range, in NM. Positions more distant than this are ignored. No limit if not set.
MAX_RANGE=360

# Network ports to listen on for connections
NET_RAW_INPUT_PORTS=
NET_RAW_OUTPUT_PORTS=30002
NET_SBS_OUTPUT_PORTS=30003
NET_BEAST_INPUT_PORTS=30004,30104
NET_BEAST_OUTPUT_PORTS=30005

# Accuracy of location written to JSON output
JSON_LOCATION_ACCURACY=1

# Additional options can be added here:
EXTRA_OPTIONS=""

# If OVERRIDE_OPTIONS is set, only those options are used; all other options
# in this config file are ignored.
OVERRIDE_OPTIONS=""

# This is a marker to make it easier for scripts to identify a v6-style config file
CONFIG_STYLE=6

The documentation for the various options can be found on Github.

Yes - I’ve seen that doc. But it does not show the values for the parameters. It doesn’t even show the full list of adaptive gain or burst parameters, which you only see if you issue the “dump1090-fa --help” command. I’m wanting to do some tuning of those parameters which are less commonly used.

These parameters are listed in the help command:

  Adaptive gain

–adaptive-burst Adjust gain for too-loud message bursts
–adaptive-burst-change-delay s Set delay after changing gain before
resuming burst control (seconds)
–adaptive-burst-alpha a Set burst rate smoothing factor
(0…1, smaller=more smoothing)
–adaptive-burst-loud-rate r Set burst rate for gain decrease
–adaptive-burst-loud-runlength l Set burst runlength for gain decrease
–adaptive-burst-quiet-rate r Set burst rate for gain increase
–adaptive-burst-quiet-runlength l Set burst runlength for gain increase

This is the parameter listing, but notice no default values are listed.

Yes I edit this file to make adjustments to the adaptive burst gain range. But it does not contain a full list of the available parameters you can see in the help command.

@obj might have answers to your questions…

Thanks - I’ve sent @obj a message. I think these lower level parameters are hard-coded into dump1090, and they’re only changed if the user specifies a different value. So they don’t normally appear in the /etc/default file.

I found the answer - should have thought to look at the source code for dump1090-fa fork. The values are in the source listing:

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