PORT is a software package dedicated to the analysis of modern and historical Very Long Baseline Interferometry (VLBI) observations. It is utilized to perform the GFZ VLBI Analysis Center responsibilities, as well as state-of-the-art research in space geodesy, geophysics, and astrometry.
The VLBI data analysis software PORT estimates Earth orientation parameters, radio telescope and radio source coordinates, as well as other, auxiliary parameters employing weighted least-squares estimation. PORT is designed to process VGOS observations, as well as traditional S-/X-band and single-band observations, regardless of data length. PORT processes both Intensive and multi-hour/day sessions.
A graphical interface supplies the user with tools to manually flag outlier data points and insert "clock breaks". Weighting of group delays and position constraints can be applied to stations, radio sources and baselines on an individual basis. The estimation results are displayed on screen and, together with the corresponding normal equations, stored on disk.
Developing PORT special care has been taken to deal with issues such as the source structure. PORT abides by the latest analysis standards suggested by the IERS (International Earth Rotation and Reference Systems Service) and the IVS (International VLBI Service for Geodesy and Astrometry), and is ITRF2020-ready.
PORT is written mainly in MATLAB, with some Python modules.
Schuh et al. (2021): The Potsdam Open Source Radio Interferometry Tool (PORT), Publications of the Astronomical Society of the Pacific, 133:104503,