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104 lines
4.0 KiB
Groff
104 lines
4.0 KiB
Groff
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.TH "rtl_adsb" 1 "0.5.0" RTL-SDR "User Commands"
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.SH NAME
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rtl_fm \- a simple FM demodulator for RTL2832 based DVB-T receivers
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.SH DESCRIPTION
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Uses a re-purposed DVB-T receiver as a software defined
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radio to receive narrow band FM signals and demodulate
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to audio. Written for and incorporated in the osmocom rtl-sdr project.
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.LP
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Narrowband FM is commonly used by public service agencies and
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commercial dispatch operations in the VHF and UHF bands.
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Also can demodulate Wideband FM, as found in the 88-108 MHz FM
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broadcast band.
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Experimental options include AM, LSB, USB and DSB demodulation.
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.LP
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Much software is available for the RTL2832. Most of the user-level
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packages rely on the librtlsdr library which comes as part of the
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rtl-sdr codebase. This codebase contains both the library itself and
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also a number of command line tools such as rtl_test, rtl_sdr,
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rtl_tcp, and rtl_fm. These command line tools use the library to test
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for the existence of RTL2832 devices and to perform basic data
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transfer functions to and from the device.
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.LP
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Because most of the RTL2832 devices are connected using USB, the
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librtlsdr library depends on the libusb library to communicate with
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the device.
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.SH USAGE
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With a suitable antenna for receiving the signal attached
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to the rtl-sdr supported device, this program will output the
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digital audio data decoded from that signal. The data can be
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listened to by piping to Sox or aplay applications to play the
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stream on the computer sound card.
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.SH SYNOPSIS
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.B rtl_fm [-f freq] [-options] [filename]
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.SH OPTIONS
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.IP "-f frequency_to_tune_to [Hz]"
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use multiple -f for scanning, (requires squelch)
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ranges supported, -f 118M:137M:25k
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.IP "[-M modulation (default: fm)]"
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fm, wbfm, raw, am, usb, lsb
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wbfm == -M fm -s 170k -o 4 -A fast -r 32k -l 0 -E deemp
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raw mode outputs 2x16 bit IQ pairs
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.IP "-s sample_rate (default: 24k)"
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.IP "-d device_index (default: 0)"
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.IP "-g tuner_gain (default: automatic)"
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.IP "-l squelch_level (default: 0/off)"
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.IP "-o oversampling (default: 1, 4 recommended)"
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for fm squelch is inverted
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.IP "[-o oversampling (default: 1, 4 recommended)]"
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.IP "-p ppm_error (default: 0)"
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.IP "[-E enable_option (default: none)]"
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use multiple -E to enable multiple options
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edge: enable lower edge tuning
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dc: enable dc blocking filter
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deemp: enable de-emphasis filter
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direct: enable direct sampling
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offset: enable offset tuning
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.IP "filename ('-' means stdout)"
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omitting the filename also uses stdout
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.SH Experimental options
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.IP "[-r resample_rate (default: none / same as -s)]"
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.IP "[-t squelch_delay (default: 10)]"
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+values will mute/scan, -values will exit
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.IP "[-F fir_size (default: off)]"
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enables low-leakage downsample filter
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size can be 0 or 9. 0 has bad roll off
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.IP "-A std/fast/lut choose atan math (default: std)"
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.IP filename
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(a '-' dumps samples to stdout)
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(omitting the filename also uses stdout)
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.SH EXAMPLES
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Produces signed 16 bit ints, use Sox or aplay to hear them.
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.IP "rtl_fm ... - | play -t raw -r 24k -es -b 16 -c 1 -V1 -"
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-M wbfm | play -r 32k ...
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.IP "rtl_fm ... -s 22050 - | multimon -t raw /dev/stdin"
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.SH SEE ALSO
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RTL-SDR wiki documentation:
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.B http://sdr.osmocom.org/trac/wiki/rtl-sdr
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.LP
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Rtl_fm Guide:
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.B http://kmkeen.com/rtl-demod-guide/
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.LP
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.sp
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sox(1), play(1), aplay(1)
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.LP
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Other rtl-sdr programs:
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.sp
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rtl_adsb(1), rtl_eeprom(1), rtl_sdr(1), rtl_tcp(1), rtl_test(1)
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.SH AUTHOR
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This manual page was written by Maitland Bottoms
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for the Debian project (but may be used by others).
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.SH COPYRIGHT
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Copyright (c) 2013 A. Maitland Bottoms <bottoms@debian.org>
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.LP
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 2 of the License, or
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(at your option) any later version.
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.LP
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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