kalibrate-rtl Package Description

Kalibrate, or kal, can scan for GSM base stations in a given frequency band and can use those GSM base stations to calculate the local oscillator frequency offset.

Source: https://github.com/steve-m/kalibrate-rtl
kalibrate-rtl Homepage | Kali kalibrate-rtl Repo

  • Author: Joshua Lackey, Steve Markgraf
  • License: Other

Tools included in the kalibrate-rtl package

kal – Calculate local oscillator frequency offset using GSM base stations
[email protected]:~# kal -h
kalibrate v0.4.1-rtl, Copyright (c) 2010, Joshua Lackey
modified for use with rtl-sdr devices, Copyright (c) 2012, Steve Markgraf
Usage:
    GSM Base Station Scan:
        kal <-s band indicator> [options]

    Clock Offset Calculation:
        kal <-f frequency | -c channel> [options]

Where options are:
    -s  band to scan (GSM850, GSM-R, GSM900, EGSM, DCS, PCS)
    -f  frequency of nearby GSM base station
    -c  channel of nearby GSM base station
    -b  band indicator (GSM850, GSM-R, GSM900, EGSM, DCS, PCS)
    -g  gain in dB
    -d  rtl-sdr device index
    -e  initial frequency error in ppm
    -v  verbose
    -D  enable debug messages
    -h  help

kal Usage Example

Scan for GSM base stations in the GSM-850 band (-s GSM850), then use channel 128 (-c 128) to get the frequency offset:

[email protected]:~# kal -s GSM850
Found 1 device(s):
  0:  ezcap USB 2.0 DVB-T/DAB/FM dongle

Using device 0: ezcap USB 2.0 DVB-T/DAB/FM dongle
Found Rafael Micro R820T tuner
Exact sample rate is: 270833.002142 Hz
kal: Scanning for GSM-850 base stations.
GSM-850:
    chan: 128 (869.2MHz - 3.988kHz) power: 486634.32
    chan: 143 (872.2MHz - 3.760kHz) power: 56331.63

[email protected]:~# kal -c 128
Found 1 device(s):
  0:  ezcap USB 2.0 DVB-T/DAB/FM dongle

Using device 0: ezcap USB 2.0 DVB-T/DAB/FM dongle
Found Rafael Micro R820T tuner
Exact sample rate is: 270833.002142 Hz
kal: Calculating clock frequency offset.
Using GSM-850 channel 128 (869.2MHz)
average     [min, max]  (range, stddev)
- 4.093kHz      [-4102, -4083]  (20, 5.314593)
overruns: 0
not found: 0
average absolute error: 4.709 ppm