.\" Manpage for front\-end\-cal. .\" Contact javier.arribas@cttc.es to correct errors or typos. .TH front\-end\-cal 1 "15 Dec 2014" "0.0.1" "front\-end\-cal man page" .SH NAME \fBfront\-end\-cal\fR \- RF front\-end center frequency and sampling rate calibration tool. .SH SYNOPSIS \fBfront\-end\-cal \-config_file=\fR\fI<path\-to\-configuration\-file>\fR [OPTION]... .SH DESCRIPTION \fBfront\-end\-cal\fR 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 \fBgnss\-sdr\fR, 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. \fBfront\-end\-cal\fR implements the algorithm proposed in [1], and it requires Internet access since it retrieves Assisted GPS data from SUPL servers. \.TP \fBfront\-end\-cal\fR 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. .SH OPTIONS \fBfront\-end\-cal\fR takes the following options: .TP \fB\-config_file=\fR\fI<path\-to\-configuration\-file>\fR Set the configuration file. .TP \fB\-signal_source=\fR\fI<path\-to\-raw\-signal\-file>\fR If defined, path to the file containing the signal samples (overrides the data file specified in the configuration file). .TP \fB\-log_dir=\fR\fI<path\-to\-directory>\fR If defined, overrides the default directory where logs are saved. .TP \fB\-version\fR Print program version and exit. .TP \fB\-help\fR Print all the available commandline flags and exit. .SH SEE ALSO .BR gnss\-sdr (1), volk_gnsssdr_profile (1) \.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 \fB\-config_file\fR option is not set. \.TP [1] C. Fernandez\-Prades, J. Arribas, P. Closas, \fITurning a Television into a GNSS Receiver\fR, in Proceedings of ION GNSS+, 15\-16 September 2013, Nashville, Tennessee (USA). A draft copy is freely available at http://www.cttc.es/publication/turning\-a\-television\-into\-a\-gnss\-receiver/ \.TP Check https://gnss\-sdr.org for more information. .SH BUGS No known bugs. .SH AUTHOR Javier Arribas (javier.arribas@cttc.es) \.TP This software has been developed at CTTC (Centre Tecnologic de Telecomunicacions de Catalunya, http://www.cttc.es) with contributions from around the world.