---
name: "front-end-cal"
section: "1"
platform: "linux"
package: "gnss-sdr"
version: "0.0.20-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/front-end-cal"
---

# front-end-cal(1)

RF front-end center frequency and sampling rate calibration tool.

## NAME

**front-end-cal** - RF front-end center frequency and sampling rate calibration tool.

## SYNOPSIS

**front-end-cal -config\_file=***\<path-to-configuration-file\>* \[OPTION\]...

## DESCRIPTION

**front-end-cal** is a calibration tool for some DVB-T receivers based on the Taiwan's Realtek RTL2832U chipset, sold in form of USB dongles that allow users to watch over-the-air DVB-T European broadcast television on their personal computers, to be used as GNSS front-ends. .TP Normally, those devices send partially-decoded MPEG transport frames over the USB, but exploiting an undocumented mode of operation of the demodulator chip, the user is able to obtain raw I&Q samples, stream them through USB to a personal computer and then use **gnss-sdr**, turning the DVB-T receiver into a GNSS receiver and delivering position in real-time. .TP The crystal oscillator that ships with the RTL2832U family devices exhibits limited accuracy to be used as a GNSS receiver front-end without previous calibration. **front-end-cal** implements the algorithm proposed in \[1\], and it requires Internet access since it retrieves Assisted GPS data from SUPL servers. .TP **front-end-cal** is able to work with raw data files or, if there is computational power enough, in real time with suitable radio frequency front-ends. The whole receiver is defined in a single configuration file, and therefore users can define theirs.

## OPTIONS

**front-end-cal** takes the following options:

- **-config\_file=***\<path-to-configuration-file\>* Set the configuration file.

  - **-signal\_source=***\<path-to-raw-signal-file\>* If defined, path to the file containing the signal samples (overrides the data file specified in the configuration file).

  - **-log\_dir=***\<path-to-directory\>* If defined, overrides the default directory where logs are saved.

  - **-version** Print program version and exit.

  - **-help** Print all the available commandline flags and exit.

  ## SEE ALSO

[**gnss-sdr**(1)](/gnss-sdr/1.md),[**volk\_gnsssdr\_profile**(1)](/volk_gnsssdr_profile/1.md) .TP Example of configuration file available at: ${prefix}/share/gnss-sdr/conf/front-end-cal.conf, where ${prefix}$ uses to be /usr or /usr/local. This will be the configuration file used by default if the **-config\_file** option is not set. .TP \[1\] C. Fernandez-Prades, J. Arribas, P. Closas, *Turning a Television into a GNSS Receiver*, in Proceedings of ION GNSS+, 15-16 September 2013, Nashville, Tennessee (USA). A draft copy is freely available at https://www.researchgate.net/publication/257137427\_Turning\_a\_Television\_into\_a\_GNSS\_Receiver .TP Check https://gnss-sdr.org for more information.

## BUGS

No known bugs.

## AUTHOR

Javier Arribas (javier.arribas@cttc.es) .TP This software has been developed at CTTC (Centre Tecnologic de Telecomunicacions de Catalunya, https://www.cttc.cat) with contributions from around the world.