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RXtoRINEX
V2.1
RXtoRINEX provides tools to collect data from GPS / GNSS receivers in mobile devices, convert them to RINEX or RTK formats, and process RINEX files.
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RXtoRINEX
V2.1
RXtoRINEX provides tools to collect data from GPS / GNSS receivers in mobile devices, convert them to RINEX or RTK formats, and process RINEX files.
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RXtoRINEX project is aimed to provide tools:
RINEX is the standard format used to feed with observation and navigation data files software packages for computing positioning solutions with high accuracy.
RINEX data files are not aimed to compute solutions in real time, but to perform post-processing, that is, GNSS/GPS receiver data are first collected into files using the receiver specific format, then converted to standard RINEX data files, and finally processed using, may be, facilities having “number-crunching” capabilities, and additional data (like data from reference stations available in UNAVCO, EUREF, GDC, IGN, and other data repositories) to allow removal of receiver data errors.
A detailed definition of the RINEX format can be found in the document "RINEX: The Receiver Independent Exchange Format Version 2.10" from Werner Gurtner; Astronomical Institute; University of Berne. An updated document exists also for Version 3.00.
RTK refers here to the data format defined for the RTKLIB (http://www.rtklib.com/) that would allow analysis of data collected with tools in this project using the RTKLIB.
Tools are provided at two levels:
Project documents can be found in the doc/html directory (https://cdn.rawgit.com/fcancillo/RXtoRINEX-V2.1/master/doc/html/index.html )
A first version of the package was released in February 2015.
The second version released in April 2016 included improvements to allow reading / filtering / converting / writing RINEX files, process GLONASS data, better isolation between OSP data acquisition and RINEX generation. The current version 2.1 released in February 2018 includes minor changes and a Linux implementation of the SerialTxRx class. The current implementation has the following scope:
Future versions to include support for other receivers would depend on availability of information from manufacturers. Any information on ICDs for other receivers (like SiRFIV-t, Broadcom, etc) is welcome.
The data tools provided are used to process or generate the following file types.
A RINEX observation file is a text file containing a header with data related to the file data acquisition, and sequences of epoch data. For each epoch the observables for each satellite tracked are included. See above reference on RINEX for a detailed description of this file format.
A RINEX navigation file is a text file containing a header with data related to the file data acquisition, and satellite ephemeris obtained from the navigation message transmitted inside the navigation satellite signal. See above reference on RINEX for a detailed description of this file format.
OSP binary are files containing OSP message data obtained from SiRF(TM) based GPS receivers. They can be embedded in the smartphone or connected to the computer or device through a serial port.
The file contains a sequence of OSP messages, where for each message they are stored the two bytes with the payload length and the n bytes of the message payload. The OSP binary file is simply the byte sequence of the transport message packet generated by the receiver after removing the bytes for "Start Sequence" (A0 A2), "Checksum" (2 bytes), and "End Sequence" (B0 B3).
A detailed definition of OSP messages can be found in the document "SiRFstarIV(TM) One Socket Protocol Interface Control Document".
GP2 debug are files containing receiver specific measurement data obtained in Android smartphones with embedded SiRFIV-T(TM) GPS receivers when DEBUGGING_FILES is set to 1 in the sirfgps.conf file.
They are text files containing in each line a time tag followed by an OSP message with byte contents written in hexadecimal.
Each line in the GP2 file has format as per the following example:
29/10/2014 20:31:08.942 (0) A0 A2 00 12 33 06 00 00 00 00 00 00 00 19 00 00 00 00 00 00 64 E1 01 97 B0 B3
Where:
Note that in above format, data from "head" to "tail" is an OSP messages with values written in hexadecimal.
Packet message files contain a sequence of binary OSP full messages. Each full message starts with the head (two bytes with values 0xA0 and 0xA2), following the payload length (a two byte integer), the payload bytes, a two bytes checksum, and finishing with the tail (two bytes with values 0xB0 and 0xB3). Between the tail of one message and the head of the following one it may be garbage data.
Such files may be captured directly through the serial port where the receiver is connected using for example a terminal emulator.
The RinexData class defines a data container for the RINEX file header records, epoch observables, and satellite navigation ephemeris.
The class provides methods:
Also it includes methods to read existing RINEX files, to store their data in the container, and to access and print them.
Methods are provided to set data filtering criteria (system, satellite, observables), and to filter data before printing.
The RTKobservation class defines data to be used for storing and further printing of a RTK file header and the position solution data of each epoch.
The GNSSdataFromOSP class defines data and methods used to acquire RINEX or RTK header and epoch data from a binary OSP file containing SiRF receiver messages.
Such header and epoch data can be used to generate and print RINEX or RTK files.
The OSPMessage class provides resources to perform data acquisition from OSP message payloads. Note that the payload is a part of the OSP message described in the SiRF ICD.
The class allows a cursor based, buffered acquisition process from the OSP file and include methods: to fill the buffer with messages read from a OSP binary file, to get values for the message data types taking into account sign and bit and byte ordering in the source, and skip unused data from the buffer.
The ArgParser class defines a data container for options and operators passed to a program as arguments in the command line, and it provides methods to manage them.
The Logger class allows recording of tagged messages in a logging file. The class defines a hierarchy of log levels (SEVERE, WARNING, INFO, CONFIG, FINE, FINER or FINEST) and provides methods to set the current log level and log messages at each level.
Only those messages having level from SEVERE to the current level stated are actually recorded in the log file.
This command line program can be used to capture OSP message data from a SiRF receiver connected to the computer / device serial port and to store them in an OSP binary file.
Data acquisition can be controlled using options to:
Note: use of this command requires a GPS receiver state compatible with data being requested: transmitting serial data at the bit rate, length and parity expected, and in OSP format. See SynchroRX command below for details.
This command line program is used to translate data captured in GP2 debug files to OSP message files.
Data translation can be controlled using options to:
This command line program is used to print contents of OSP files into readable format. Printed data are sent to the stdout.
The output contains descriptive relevant data from each OSP message:
This command line program is used to generate RINEX files from an OSP data file containing SiRF receiver message data.
The generation of RINEX files can be controlled using options to:
This command line program is used to generate a RTK file with positioning data extracted from an OSP data file containing SiRF IV receiver messages.
The generation of RTK files can be controlled using options to:
This command line program can be used to synchronize SiRF based receiver and computer to allow communication between both.
The receiver state is defined by the following:
The computer data acquisition process state is defined by:
To allow communication between GPS receiver and computer, states of both elements shall be synchronized according to the needs stated.
Synchronization requires first to know the current state of receiver and computer port, and then change both to the new state. But, to know the receiver state is necessary to communicate with it, setting the computer port at the same speed, stop bits and parity that the receiver. This will allow receiving and analyzing the data being generated by the receiver to know the protocol it is using. As receiver state may be not known initially, it would be necessary to scan different communication alternatives to know it.
To allow synchronization it is assumed the following for the receiver:
After synchronization, bit rates will be set to 9600 bps when exchanging NMEA data or to 57600 bps when exchanging OSP messages.
The synchronization process can be controlled using options to:
This command line program is used to extract from an input binary file containing SiRF receiver message packets their payload data, and store them into an OSP binary file. Such input files can be obtained from the receiver data stream using system tools, or application specific ones.
The command extracts and verifies message packets, and writes the payload data of the correct ones to the OSP binary file.
This command line program is used to generate a RINEX file from data contained in another RINEX file.
The command allows user to change version of the output file (with regard to input file), and filtering its data.
To filter input observation data the user can define:
To filter input navigation data the user can define similar criteria, except system / observable.
This command line program is used to generate a CSV or TXT file from data contained in a given observation or navigation RINEX file.
Input data are contained in a RINEX observation or navigation file containing header and epoch data.
The outputs are CSV (Comma Separated Values) text data files: one containing header data, and the other containing epoch data (observation or navigation, depending on the RINEX file type). This type of files can be used to import data to some available applications (like MS Excel).
The command allows user to filter input file data to be converted. To do that, user can define:
The directory ./Data contains sample files obtained with the above described tools.
Contains GPS data acquired with an external GlobalSat G-Star IV model BU-353S4 (SiRFIV-e receiver). Each subdirectory inside includes data files from a survey:
In addition there are files with analysis data from teqc and from PRSolve (part of the GPS ToolKit).
Contains GPS data acquired with a Samsung Galaxy S2 (GT-I9100) from its embedded receiver (a SiRFIV-t). Each subdirectory inside includes data for different surveys, including:
As per GStarIV, but using data captured by a SiRFV based receiver.
As per GStarIV, but using data captured using a PC running Ubuntu.
1.8.9.1
