Uniting Global Efforts to Calibrate GNSS Antennas

Models, analyses and pilot results

authored by: Tobias Kersten, Igor Sutyagin, Andria Bilich, Steffen Schön
Abstract: Calibrations of GNSS receiver antennas to compute phase center corrections (PCCs) is an important product for reference frame determination. Research also demonstrates that PCCs affect position accuracy, troposphere modeling, and clock estimation. In recent years, multiple institutions have started calibrating receiver antennas, with a desire to contribute their PCCs to the IGS ANTEX. These institutions have a large variety of environments, equipment, software, and computation techniques. Thus it is important to verify the consistency of calibration results before the PCCs can be validly combined into a master IGS ANTEX file.

With support from the IGS Antenna Committee, the authors organized a “ring calibration” or “ringcal” experiment to directly compare results from multiple techniques. The campaign aims to understand technique differences, identify the degree of agreement, improve the consistency of calibration results, and develop a strategy and quality assessment of carrier phase and code calibrations.

Towards these goals, six antennas were circulated to 9 different institutions worldwide, for individual calibration. Participants shared their multi-GNSS phase calibrations in ANTEX format, as well as detailed information on their equipment and technique. This contribution reviews the current status of this campaign, and provides new comparison and evaluation results for carrier phase patterns.

Assessment of the ringcal results is obviously crucial to this campaign, yet to date there are no community-accepted comparison maths or software to validly compare and analyze PCCs. The authors developed new formulae for PCC comparison and PCO computation, and new metrics to summarize the 3D nature of each calibration. The authors also introduce new open-source software to implement these strategies and compare calibration values, numerically and graphically. We use the current software to compare the ringcal data, and call upon the community to help with additional development.

Ultimately, the impact of different PCC definitions on the IGS station positions and reference frame determination is of utmost importance. We call on the IGS community to provide feedback on preferred analysis methods and assistance in studying the impact of these PCCs on IGS products and services.
Organisation(s): Institute of Geodesy
External Organisation(s): Topcon Positioning Systems, Livermore
National Geodetic Survey (NGS)
Type: Slides to presentation
Publication date: 01.07.2024
Publication status: E-pub ahead of print
Research Area (based on ÖFOS 2012): Satellite geodesy
Sustainable Development Goals: SDG 9 - Industry, Innovation, and Infrastructure
: Details in the research portal "Research@Leibniz University"

BibTeX

@conference{d09608ea092c482b9a327d5f9eeb21bd,
title = "Uniting Global Efforts to Calibrate GNSS Antennas: Models, analyses and pilot results",
abstract = "Calibrations of GNSS receiver antennas to compute phase center corrections (PCCs) is an important product for reference frame determination. Research also demonstrates that PCCs affect position accuracy, troposphere modeling, and clock estimation. In recent years, multiple institutions have started calibrating receiver antennas, with a desire to contribute their PCCs to the IGS ANTEX. These institutions have a large variety of environments, equipment, software, and computation techniques. Thus it is important to verify the consistency of calibration results before the PCCs can be validly combined into a master IGS ANTEX file.With support from the IGS Antenna Committee, the authors organized a “ring calibration” or “ringcal” experiment to directly compare results from multiple techniques. The campaign aims to understand technique differences, identify the degree of agreement, improve the consistency of calibration results, and develop a strategy and quality assessment of carrier phase and code calibrations.Towards these goals, six antennas were circulated to 9 different institutions worldwide, for individual calibration. Participants shared their multi-GNSS phase calibrations in ANTEX format, as well as detailed information on their equipment and technique. This contribution reviews the current status of this campaign, and provides new comparison and evaluation results for carrier phase patterns.Assessment of the ringcal results is obviously crucial to this campaign, yet to date there are no community-accepted comparison maths or software to validly compare and analyze PCCs. The authors developed new formulae for PCC comparison and PCO computation, and new metrics to summarize the 3D nature of each calibration. The authors also introduce new open-source software to implement these strategies and compare calibration values, numerically and graphically. We use the current software to compare the ringcal data, and call upon the community to help with additional development.Ultimately, the impact of different PCC definitions on the IGS station positions and reference frame determination is of utmost importance. We call on the IGS community to provide feedback on preferred analysis methods and assistance in studying the impact of these PCCs on IGS products and services.",
keywords = "GNSS, antenna calibration, antenna phase centre variations, antenna phase centre offsets, GNSS, antenna calibration, antenna phase centre variations, antenna phase centre offsets",
author = "Tobias Kersten and Igor Sutyagin and Andria Bilich and Steffen Sch{\"o}n",
year = "2024",
month = jul,
day = "1",
language = "English",
note = "IGS Symposium and Workshop 2024 : 30 years of IGS, IGS2024 ; Conference date: 01-07-2024 Through 05-07-2024",
url = "https://igs.org/workshop/2024/",
}