High-precision GNSS-based positioning relies on accurate antenna Phase Center Corrections (PCC). However, the lack of universally accepted ground truth for antenna calibration values leads to discrepancies between results from different calibration facilities and methods. These differences (dPCC) are typically analyzed in the PCC domain as defined by the Antenna Exchange (ANTEX) format. Yet, agreement at the PCC grid level does not directly reflect the impact on estimated geodetic parameters. We present PCC-Suite, an open-source Python toolkit with user-friendly graphical interfaces for exploring, converting, visualizing and analyzing PCC or dPCC. ATX-Scanner enables search and filtering of ANTEX files by antenna type, frequency, calibration method, and other metadata. PCC-Viewer visualizes PCC or dPCC for selected frequencies and ionosphere-free linear combinations (IF-LC), using stereographic projections and azimuth-averaged profiles. ATX-Converter provides bidirectional conversion between ANTEX versions 1.4 and 2.0. The core component, PCC-Explorer, quantifies the impact of PCC or dPCC on geodetic parameters, i.e., topocentric coordinate differences, receiver clock estimates and tropospheric parameters, under realistic multi-GNSS conditions. The software processes ANTEX data (v1.4 or v2.0), supports major GNSS constellations and frequencies, and allows user-defined IF-LC. Configurable parameters include station location and time span, azimuth/elevation masks, observation weighting, tropospheric mapping functions, sampling rate, and solution length (e.g., 3 h or 24 h). It further enables regional to global impact assessments on user-defined grids. The analysis is focused on geodetic parameters of operational significance for GNSS users and network providers. Exemplary simulations are interpreted and validated against Precise Point Positioning (PPP) solutions derived from real GNSS observations from the IGS antenna calibration campaign. In addition, a kinematic mode is presented, allowing users to import a trajectory to assess the impact of dPCC on geodetic parameters along a moving path. Overall, PCC-Suite enables GNSS users and network operators to make informed assessments of calibration quality and thus supports standardized, reproducible, and reliable evaluation of the influence of calibration results on geodetic parameters.

Antennas for receiving signals from Global Navigation Satellite Systems (GNSS) are the first element in the GNSS data processing chain. The antenna performance determines not only the sensitivity to the useful GNSS signal information, but also to the most prominent error sources that prevent safe and ac- curate positioning, namely multipath and interference. The issue of interference is also present at larger distances from conflict regions, affecting civilian geodetic infrastructure and civil aviation. Jamming and spoofing call for more resilient GNSS antenna designs, with multi-antenna systems being among the most effective countermeasures for achieving robust GNSS performance. For highly precise and accurate GNSS-based positioning, Phase Center Corrections (PCC) and Code Phase Corrections (CPC) need to be applied. The determination of these corrections is known as an- tenna calibration and can be done either in the field using a robot and real GNSS signals or in an anechoic chamber using artificially generated signals. In our contribution, we briefly introduce the main objectives of the project RENEGANT (Get REady for NExt Generation of GNSS ANTenna systems). It is a collaborative DFG-funded project between the Institut für Erdmessung (IfE) and the Institute of Communications and Navigation at DLR. The project aims to develop a novel robot-based calibration methodology using real GNSS signals to characterize multi-antenna arrays, while simultaneously investigating the impact of calibration setups, particularly for miniaturized antennas, on CPC and PCC. This contribution presents first comparisons between calibrations of a small u-blox ANN-MB1 an- tenna on a robot at IfE using real GNSS signals and calibrations of the same antenna conducted in a semi-anechoic chamber at DLR. Observed differences are discussed in terms of signal noise, near-field effects induced by the robot platform, and potential impact from the antenna holder used in the chamber environment. Furthermore, first calibration results for individual elements of a Controlled Reception Pattern An- tenna (CRPA) array are presented. The estimated phase center locations of these elements are visualized, highlighting the importance of accounting for active components, such as Low Noise Amplifiers (LNAs), which may significantly influence CPC and PCC due to their electromagnetic interaction with the receiving antenna elements.

Geodetic monitoring of unstable slopes is essential for quantifying ground deformation and assessing infrastructure safety in mountainous regions. This study investigates the temporal and spatial deformation behaviour of the Latyan landslide mass in northern Iran using a satellite-based geodetic control network and multi-epoch GNSS observations. A rigorous least-squares adjustment was applied to estimate horizontal and vertical displacement components and evaluate the statistical reliability of the network solution. The results indicate a clear spatial pattern of deformation, where maximum displacements occur at stations L4, L3, L2, and L13 located within the active landslide zone, while minimum movements are observed at stations G15, G11, L1, L10, and L16–L22 situated outside the deformation influence area. Variance–covariance analysis confirms the robustness and internal consistency of the geodetic solution, demonstrating that observed deformation significantly exceeds measurement noise levels in active zones. The results further show that satellite-based geodetic monitoring provides a reliable and efficient alternative to classical terrestrial surveying in complex and inaccessible terrain. The study confirms the capability of geodetic network adjustment combined with satellite observations for precise detection and interpretation of slope deformation processes and highlights its applicability for infrastructure monitoring and hazard assessment in dam catchments.

Deformation analysis using terrestrial laser scanners (TLS) becomes increasingly popular. More and more methods to determine even the smallest movements in TLS point clouds appear in current research. However, such tasks require precise knowledge of the underlying variances of the observations. The lack of information or the use of incorrect stochastic information leads to parameters without meaningful significance. We propose a method to determine the angular variances of a TLS empirically. Specifically, the Z+F IMAGER ® 5016A is used in the development process. We are able to determine both horizontal and vertical angular variances of given TLS. In combination with the well known intensity-based range variance model, this is the first time that the variances of all three observables of a TLS are determined empirically. Unlike existing approaches that mainly use target center estimation (TCE) based approaches, our method realizes the angular variance in the intensity observation. This allows the determination of the variance of an individual angular observation, rather than smoothing over multiple observations as is done in TCE. An in-situ quantification and reduction of the intensity measurement variance allows the decomposition of noise sources until the angular contribution is separated. Determined angular variances can be modeled with a functional relationship in dependence on the respective rotational speed. Both horizontal and vertical angular standard deviations, the square-root of the variances, are significantly smaller than the manufacturer’s claim of up to 14.4”. Determined horizontal angular standard deviations range from ≈0.7” to ≈2”, with higher rotational speeds leading to lower standard deviations. Vertical angular standard deviations show a range from ≈1” to ≈3” with higher rotational speeds leading to higher vertical angular standard deviations. In addition to the Z+F IMAGER ® 5016A, two TLS with identical hardware specifications but differences in firmware and age were analyzed. The results show similarities in determined angular variances for the same hardware and differences for scanners of different age and servicing history.