Anna Krypiak-Gregorczyk

University of Warmia and Mazury in Olsztyn · Institute of Geodesy

Swarm electron density (Ne) observations from the Langmuir probe (LP) can detect ionospheric disturbances at the altitude of a satellite. Along-track satellite observations provide a large number of very short observations of different places in the ionosphere, where Ne is disturbed. Moreover, different perturbations occupy various Ne signal freque...

In this article, we show the capability of a global navigation satellite system (GNSS) precise orbit determination (POD) low Earth orbit (LEO) data to detect anomalous ionospheric disturbances in the spectral range of the signals associated with earthquakes and tsunamis, applied to two of these events in Papua New Guinea (PNG) and the Solomon Islan...

The study investigates ionospheric electric field responses to the earthquake (EQ) of magnitude 8.3, and to the related seismic activity and tsunami triggered by the mainshock in Chile-Illapel region, at 22:54 UTC, in the evening of 16.09.2015. The work is a wider review of available ground and satellite data and techniques available in detection o...

In this manuscript, we introduce the Ionospheric Tomographic Common Clock (ITCC) model of undifferenced uncombined GNSS measurements. It is intended for improving the Wide Area precise positioning in a consistent and simple way in the multi-GNSS context, and without the need of external precise real-time products. This is the case, in particular, o...

Global ionosphere maps (GIMs) representing ionospheric total electron content (TEC) are applicable in many scientific and engineering applications. However, the GIMs provided by seven Ionosphere Associated Analysis Centers (IAACs) are generated with different temporal resolutions and using different modeling techniques. In this study, we focused on...

Ionosphere Associate Analysis Centers (IAACs) of the International GNSS Service (IGS) independently produce global ionosphere maps (GIMs) of the total electron content (TEC). The GIMs are based on different modeling techniques, resulting in different TEC levels and accuracies. In this study, we evaluated the accuracy and consistency of the IAAC GIM...

The study intercompares three stochastic interpolation methods originating from the same geostatistical family: least-squares collocation (LSC) known from geodesy, as well as ordinary kriging (OKR) and universal kriging (UKR) known from geology and other geosciences. The objective of this work is to assess advantages and drawbacks of fundamental di...

This part of the Polish National Report concerns research on Satellite Geodesy performed in Poland from 2018 to 2020. The activity of the Polish institutions in the field of satellite geodesy and navigation are focused on the several main fields: global and regional GPS and SLR measurements in the frame of International GNSS Service (IGS), Internat...

Geostatistical Analyst is a set of advanced tools for analysing spatial data and generating surface models using statistical and deterministic methods available in ESRI ArcMap software. It enables interpolation models to be created on the basis of data measured at chosen points. The software also provides tools that enable analyses of the data vari...

Precise real-time kinematic (RTK) Global Navigation Satellite System (GNSS) positioning requires fixing integer ambiguities after a short initialization time. Originally, it was assumed that it was only possible at a relatively short distance from a reference station (<10 km), because otherwise the atmospheric effects prevent effective ambiguity fi...

This article describes an implementation of precise point positioning (PPP) and the least-squares collocation (LSC) method in the modeling of total electron content (TEC) in Southeast Asia, which is characterized by relatively homogeneous Global Navigation Satellite Systems (GNSS) data from International GNSS Service (IGS) stations and the occurren...

Recent Solar Cycle 24 is characterized by the occurrence of three strong disturbances near an equinox. In this contribution, the responses of the ionosphere to the equinox storms in 2012, 2013 and 2015 driven by coronal mass ejections were analyzed. Due to the dynamic nature of changes in the ionosphere, the accuracy and resolution of existing glob...

The research conducted within the International Association of Geodesy (IAG) Real Time Ionosphere Monitoring Working Group (RTIM-WG), which is part of IAG’s Sub-Commission 4.3 “Atmosphere Remote Sensing”, will be presented. In particular, we will focus on the comparison and validation of real-time and near real-time VTEC Global Ionopheric Maps (GIM...

The ionosphere can be modeled and studied using multi-frequency GNSS signals and their geometry-free linear combination. Therefore, a number of GNSS-derived ionospheric models have been developed and applied in a broad range of applications. However, due to the complexity of estimating the carrier phase ambiguities, most of these models are based o...

The ionosphere is still considered one of the most significant error sources in precise Global Navigation Satellite Systems (GNSS) positioning. On the other hand, new satellite signals and data processing methods allow for a continuous increase in the accuracy of the available ionosphere models derived from GNSS observables. Therefore, many researc...

High precision Global Navigation Satellite Systems (GNSS) positioning and time transfer require correcting signal delays, in particular higher-order ionospheric (I2+) terms. We present a consolidated model to correct second- and third-order terms, geometric bending and differential STEC bending effects in GNSS data. The model has been implemented i...

The first order ionospheric term (I1) is the main contributor to the ionospheric delay of GNSS observations, compared with the less than 0.1% corresponding to the higher order ionospheric terms. However, higher order ionospheric effects (I2+) are one of the main limiting factors in very precise GNSS processing, for applications where millimetre acc...

See abstract at: http://meetingorganizer.copernicus.org/EGU2017/EGU2017-16702.pdf

In this paper, the authors summarize a simple and efficient approach developed to mitigate the problem in precise GNSS positioning originated by the most frequent ionospheric wave signatures: the Medium Scale Travelling Ionospheric Disturbances (MSTIDs). The direct GNSS Ionospheric Interferometry technique (hereinafter dGII), presented in this pape...

The ionosphere plays a crucial role in space weather that affects satellite navigation as the ionospheric delay is one of the major errors in GNSS. On the other hand, GNSS observations are widely used to determine the amount of ionospheric total electron content (TEC). An important aspect in the electron content estimation at regional and global sc...

The ESA PIOM-FIPP research study of MSTID determination and application to precise GNSS positioning over Poland faced an unexpected and main issue in the first stage of the project development: the lack of enough populated local GNSS networks over most part of Europe, in order to apply the foreseen state of the art MSTID propagation techniques. In...

The paper presents the structure, performance and preliminary results of new ionosphere monitoring service over the ASG-EUPOS network of GNSS reference stations in Poland. This dense permanent network consisting of ~110 stations is a part of the European Position Determination System (EUPOS) project involving 18 countries of Central and Eastern Eur...

This paper presents accuracy analyses of two near real-time tropospheric delay estimation models, IGGHZG and IGGHZM, in fast-static precise positioning. The first model is based on the processing of GPS data collected from ground-based reference stations, and the second one uses metrological data fed into the Saastamoinen model. These two methods w...

In ultra-fast static satellite positioning successful ambiguity resolution mostly depends on the accuracy of the applied atmospheric - ionospheric and tropospheric - corrections. In case of Ground Based Augmentation Systems (GBAS), such corrections are usually derived from the reference network solution, and subsequently provided to the user. The a...

The aim of this study was to assess the performance of several approximation techniques for ionospheric total electron content (TEC) mapping. Approximation techniques based on data-fitting with local or general two-dimensional polynomials, local planes or distance-dependent interpolation were applied and tested. For the ionosphere modeling, dual-fr...

The electron density profiles retrieved from the Formosat-3/COSMIC radio occultation measurements were analyzed within the case-study of geomagnetic disturbance on October 11, 2008. The distinctive feature of this moderate geomagnetic storm was the short duration of the ionospheric effect. For the European region the strong short-term (about 2 hour...

An instantaneous (single-epoch) long-range RTK positioning using data from multiple Global Navigation Satellite Systems (GNSS) is currently being implemented and tested in the GINPOS software, developed at the University of Warmia and Mazury in Olsztyn. The instantaneous ambiguity resolution has several advantages; it is resistant to negative effec...

This research is motivated by the recent IGS Ionosphere Working Group recommendation issued at the IGS 2010 Workshop held in Newcastle, UK. This recommendation encourages studies on the evaluation of the application of COSMIC radio occultation profiles for additional IGS global ionosphere map (GIM) validation. This is because the reliability of GIM...

In order to estimate the plasmaspheric electron content (PEC) the GPS observations, ionosonde measurements and radio occultation (RO) data were analyzed. GPS observations provide information about values of vertical total electron content (TEC) up to the 20200 km. Ionosonde measurements retrieve bottomside part of electron density profiles, while R...

In order to enhance our understanding of the rich plasma physical processes that drives the solar-terrestrial space environment we need to dramatically increase our ability to perform multi point measurements with sensors of different types. The magnetosphere-ionosphere-thermosphere system is strongly affected by electric and magnetic fields, parti...

Different radio sounding techniques are used to the study of the ionosphere state. In the given paper analysis of ionospheric electron density and contribution of different parts of the ionosphere to the total electron content (TEC) was carried out on the base of measurements provided by GPS transionospheric sounding, vertical ionospheric sounding...

In this report we present an analysis of the ionospheric response to moderate (Dst<70 nT), 11 October 2008, geomagnetic storm. TEC maps over European region were created on the base of GPS observations provided by IGS/EPN. Strong short-term positive effect was detected near noon of 11 October 2008. The TEC enhancement exceeded 100% on latitudes of...

FormoSat-3/COSMIC now provides unprecedented global coverage of GPS occultations mea-surements, each of which yields the ionosphere electron density information with high vertical resolution. However systematic validation work is still needed before using the powerful RO technique for sounding the ionosphere on a routine basis. In the given study e...

The solar minimum began around March 2006 and many predictions of the start and size of Solar Cycle 24 were given since then. In 2007 the Solar Cycle 24 Prediction Panel anticipates the solar minimum marking the onset of Cycle 24 will occur in March 2008 (6 months). Then this date was shifted to the August 2008, after that -to the December 2008. At...

In the given report we present results of statistical comparison of NmF2 values retrieved by independent measurement technique -COSMIC Radio Occultation and vertical ionospheric sounding. We used the ionospheric data recorded by European digisondes of DIAS network for different seasons of 2008 and compare these ground measured data with the GPS COS...

Electron density profiles retrieved from the Formosat-3/COSMIC radio occultation (RO) measurements were compared to ground-based ionosphere measurements and the IRI model predictions. Ionospheric data recorded by European ionosonde stations (Rome, Ebro, Arenosillo, Athens, Pruhonice and Juliusruh) during years of 2007-2008 were compared to COSMIC-d...

Simultaneous GPS observations from about 150 stations of European Permanent Network (EPN) have been used for studying dynamics of latitudinal profiles and structure of mid-latitude ionospheric trough (MIT). For the analyses, the TEC maps over Europe were created with high spatial and temporal resolution. The latitudinal profiles were produced from...

With increasing reliance on space-based platforms for global navigation and communication, concerns about the impact of ionospheric scintillation and total electron content (TEC) fluctuations on these systems have became a high priority. In this paper, GPS trans-ionospheric signals have been used to study the development of ionospheric phase fluctu...

The analysis of occurrence of ionospheric electron content to the large solar flare that occurred near 11 00 UT on November 28, 2003 (class X17) is presented. The TEC data were obtained using GPS observations carried by European Permanent Network (EPN) and International GNSS Service (IGS). The detail pictures of TEC response to the solar flare over...