RINEX

Abstract: This paper presents a brief overview of an open-source, MATLAB software Global Positioning System (GPS) receiver. All functions from signal acquisition to position solution are described. The focus is then turned to developments at the University of Colorado, Boulder related to the software receiver. A Universal Serial Bus (USB) intermediate frequency (IF) data sampler module is described that researchers can use to collect data to support their research. Student projects that were the outcome of a graduate level global navigation satellite system (GNSS) receiver architecture course are also described. These projects included signal acquisition and tracking in a field-programmable gate array (FPGA), multi-correlator signal tracking, L2C acquisition, and Galileo signal tracking. The validity of the existing software receiver as a base for future research was confirmed by the success of these projects. The results from Wide Area Augmentation System (WAAS) ranging, WAAS correction decoding, and navigation solution filtering are described all with the intent of improving positioning accuracy.

Abstract: For many common GPS/GLONASS native receiver formats, a single freeware program called TEQC now allows the user to translate from the binary receiver format to the standard Receiver Independent Exchange (RINEX) format, to edit existing RINEX files, and to quality-check the data before postprocessing. TEQC is 100% noninteractive and has a command line interface modeled after common UNIX commands. This combined with TEQC's extensive documentation makes it simple to use for new and experienced users and in automated processing scripts. © 1999 John Wiley & Sons, Inc.

Abstract: (Revision, April 1993) (Clarification December 1993) (Doppler Definition: January 1994) (PR Clarification: October 1994) (Wlfact Clarification: February 1995) (Event Time Frame Clarification: May 1996) (Minor errors in the examples A7/A8: May 1996) (Naming convention for compressed met files; January 1997) (Continuation line clarifications: April 1997) (GLONASS Extensions: April 1997) (Met sensor description and position records: April 1997) (Wavelength factor clarifications: April 1997) (Error in example A12: CORR TO SYSTEM TIME, April 1997) (Redefinition of sv clock params in GLONASS Nav Mess Files: March 1998) (Naming conventions for compressed RINEX obs files: March 1998) (GPS week: No roll-over, continuous number: March 1998) (Error in compressed DOS file naming convention: July 1998) (Table A13 contained blank satellite identifiers: Sept 1998) (Discrepancy between Tables A5 and A9 removed: Sept 1998)

Abstract: The world of satellite navigation is undergoing dramatic changes with the rapid development of multi-constellation Global Navigation Satellite Systems (GNSSs). At the moment more than 70 satellites are already in view, and about 120 satellites will be available once all four systems (BeiDou + Galileo + GLONASS + GPS) are fully deployed in the next few years. This will bring great opportunities and challenges for both scientific and engineering applications. In this paper we develop a four-system positioning model to make full use of all available observations from different GNSSs. The significant improvement of satellite visibility, spatial geometry, dilution of precision, convergence, accuracy, continuity and reliability that a combining utilization of multi-GNSS brings to precise positioning are carefully analyzed and evaluated, especially in constrained environments.