rtl_sdr

TLDR

Capture to file

$ rtl_sdr -f [100M] [capture.bin]

Set sample rate

$ rtl_sdr -f [100M] -s [2.4M] [capture.bin]

Set gain

$ rtl_sdr -f [100M] -g [40] [capture.bin]

Capture duration

$ rtl_sdr -f [100M] -n [1000000] [capture.bin]

Frequency offset correction

$ rtl_sdr -f [100M] -p [55] [capture.bin]

Select device

$ rtl_sdr -d [0] -f [100M] [capture.bin]

Direct sampling mode

$ rtl_sdr -f [3M] -D [2] [capture.bin]

SYNOPSIS

rtl_sdr [-f freq] [-s rate] [-g gain] [options] output

rtl_sdr captures radio signals using RTL-SDR dongles. These are low-cost software-defined radio receivers.
Frequency range typically 24-1766 MHz. The actual range depends on the tuner chip.
Sample rate determines bandwidth captured. Higher rates capture more spectrum.
Gain adjustment controls receiver sensitivity. Auto-gain or manual values.
Output is raw I/Q samples. Post-processing decodes various signals.
PPM correction compensates for oscillator error. Calibrate using known signal.

PARAMETERS

-f FREQ

Center frequency (Hz).

-s RATE

Sample rate (Hz).

-g GAIN

Gain (0 for auto).

-n SAMPLES

Number of samples.

-p PPM

Frequency correction.

-d INDEX

Device index.

-D MODE

Direct sampling mode.

-S

Enable synchronous mode.

CAVEATS

Requires RTL-SDR compatible device. USB bandwidth limits sample rate. Heat affects frequency stability.

HISTORY

rtl_sdr is part of librtlsdr, enabling RTL2832U-based DVB-T dongles for SDR. Created by Steve Markgraf and others, it revolutionized accessible software-defined radio.