kalibrate-rtl 介绍

Kalibrate,或KAL,可以扫描指定频带GSM基站,并且可以使用那些GSM基站计算本地振荡器频率偏移量。

资料来源:https://github.com/steve-m/kalibrate-rtl
kalibrate-rtl 首页
kalibrate-rtl 源代码版本库

包含kalibrate-RTL里的工具

KAL - 计算本地GSM振荡频率基站偏移量

:~# 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 用法示例

扫描在GSM-850频段GSM基站(-s GSM850),然后使用信道128(-c 128),以获得频率偏移量:

:~# 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

:~# 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