The GPSTk: an open source GPS toolkit

Abstract

Applied Research Laboratories, The University of Texas at Austin (ARL:UT) has established a cross platform open source software project called the GPSTk or the GPS Toolkit. The GPSTk consists of a library and collection of applications that support GPS research, analysis, and development. The code is released under the terms of the Lesser GNU Public License. The GPSTk supports a broad range of functionality. This includes reading and writing observations in standard formats, such as RINEX, BINEX, and SP3, ephemeris evaluation, position determination, receiver autonomous integrity monitoring (RAIM), atmospheric delay modeling, cycle slip detection and correction, and P-code generation. The GPSTk provides the core set of functionality that is used for GPS research and development at ARL:UT. ARL:UT has been involved with satellite navigation since Transit (the precursor to GPS) in the 1960s and is currently conducting research in a wide variety of GPS-related fields, including precise surveys, monitor station networks, and ionospheric studies. The GPSTk is a community-wide resource for all users of GPS and GNSS technology. Participation is welcomed in all areas including: bug reports, new algorithms, suggestions for improvement, and contributions of additional functionality or applications. ARL:UT continually improves the library, shepherds community participation, and is committed to the project's development and maintenance.The GPS Toolbox is a column dedicated to highlighting algorithms and source code utilized by GPS Engineers and scientists. If you have an interesting program or software package you would like to share with our readers, please pass it along; e-mail it to us at gps-toolbox@ngs.noaa.gov. To comment on any of the source code discussed here, or to download source code, visit our website at http://www.ngs.noaa.gov/gps-toolbox.

Vertical coupling of atmospheres: dependence on strength of sudden stratospheric warming and solar activity

“…One may note that the Diego Garcia station falls approximately under the southern crest of the EIA. The receiver independent exchange (RINEX) format International GNSS Service (IGS) (Dow et al 2009) data are processed using open-source GPS ToolKit (GPSTk) (Harris and Mach 2007;Laskar et al 2013). While calculating vertical TEC values, satellites with elevation angles greater than 50°are considered, which remove the dependence of TEC on ionospheric pierce point height and latitude, in addition to multipath effect in the low latitudes (Rama Rao et al 2006;Bagiya et al 2009).…”

Ray-traced troposphere slant delays for precise point positioning

“…As some of the receivers are located very close to each other, it is expected that any systematic errors introduced by numerical weather models will be reflected by similar differences between the estimated position and the IGS solution. Thus, RINEX files were downloaded, screened for irregularities and repaired if necessary using GPSTK (Harris and Mach, 2007) in order to guarantee that KARAT will not encounter any troubles due to data-gaps or RINEX format inconsistencies. Based on these data, a second set of RINEX files has been generated for which the troposphere slant delays from ray-tracing calculations have been removed.…”

Comparative quality analysis of models of total electron content in the ionosphere

“…The most natural means of assessing the quality of GEMTEC and NTCM GL models is to conduct mass calculations of positioning errors in comparison with the use of the Klobuchar model. Such testing was con ducted with the GPS Toolkit (Harris and Mach, 2007), which includes RINEXPVT-a program designed for solving the navigation problem in the mode of post pro cessing of real data represented by the so called observa tion and navigation RINEX files. These data for naviga tion satellite monitoring stations belonging to the IGS network were taken from http://sopac.ucsd.edu/cgi bin/ dbDataBySite.cgi.…”