Wojciech Jarmołowski

• Dr hab inż.
• Professor (Associate) at University of Warmia and Mazury in Olsztyn

Atmospheric responses to earthquakes or volcanic eruptions have become an interesting topic and can potentially contribute to future forecasting of these events. Extensive anomalies of the total electron content (TEC) are most often linked with geomagnetic storms or Earth-dependent phenomena, like earthquakes, volcanic eruptions, or nuclear explosi...

This study demonstrates a rich complexity of the time–frequency ionospheric signal spectrum, dependent on the measurement type and platform. Different phenomena contributing to satellite-derived and ground-derived geophysical data that only selected signal bands can be potentially sensitive to seismicity over time, and they are applicable in lithos...

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...

Ionospheric irregularities impair Global Navigation Satellite System (GNSS) signals and, in turn, affect the performance of GNSS positioning. Such effects are especially evident at low and high latitudes, which are currently gaining the attention of research and industry sectors. This study evaluates the impact of ionospheric irregularities on GNSS...

This paper addresses the long-term climatology (over two solar cycles) of total electron content (TEC) irregularities from a polar cap station (Thule) using rate of change of TEC index (ROTI). The climatology reveals various variabilities over different time scales, i.e., solar cycle, seasonal, and diurnal variations. These variations in different...

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...

We present the Optical Flow algorithm for forecasting the Rate Of total electron content Index (OFROTI). It consists of a method for predicting maps of rapid fluctuations of ionospheric electron content in terms of Global Navigation Satellite Systems (GNSS) dual-frequency phase measurements of the rate of change of total electron content index (ROT...

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...

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...

In 2019, the University of Warmia and Mazury in Olsztyn, in cooperation with Astri Polska, started a European Space Agency (ESA) project. The purpose of the project is the development and implementation of a field calibration procedure for a multi-frequency and multi-system global navigation satellite system (GNSS). The methodology and algorithms p...

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 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...

Maximum likelihood (ML) and restricted maximum likelihood (REML) are nowadays very popular in geophysics, geodesy and many other fields. There is also a growing number of investigations into how to calculate covariance parameters by ML/REML accurately and fast, and assure the convergence of the iteration steps in derivative-based approaches. The la...

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 article describes an implementation of the negative log-likelihood function in the determination of uncorrelated noise standard deviation together with the parameters of spherical signal covariance model in least squares collocation (LSC) of gravity anomalies. The correctness and effectiveness of restricted maximum likelihood (REML) estimates a...

Unpublished poster concluding PhD Thesis in a very short way. It summarizes comparison of geoid modeling by LSC and spherical FFT usimg gravsoft programs GPCOL and SPFOUR.

The work investigates the spatial correlation of the data collected along orbital tracks of Mars Orbiter Laser Altimeter (MOLA) with a special focus on the noise variance problem in the covariance matrix. The problem of different correlation parameters in along-track and crosstrack directions of orbital or profile data is still under discussion in...

The article describes the estimation of a priori error associated with heterogeneous, non-correlated noise within one dataset. The errors are estimated by restricted maximum likelihood (REML). The solution is composed of a cross-validation technique named leave-one-out (LOO) and REML estimation of a priori noise for different groups obtained by LOO...

Precise estimates of the covariance parameters are essential in least-squares collocation (LSC) in the case of increased accuracy requirements. This paper implements restricted maximum likelihood (REML) method for the estimation of three covariance parameters in LSC with the Gauss-Markov second-order function (GM2), which is often used in interpola...

The paper describes the estimation of covariance parameters in least squares collocation (LSC) by the cross-validation (CV) technique called leave-one-out (LOO). Two parameters of Gauss-Markov third order model (GM3) are estimated together with a priori noise standard deviation, which contributes significantly to the covariance matrix composed of t...

The article describes preliminary results of the augmentation of Global Navigation Satellite System/Inertial Navigation System positioning (GNSS/INS) by Digital Elevation Model (DEM) based on the data from the Shuttle Radar Topography Mission (SRTM) and data from field survey. The prototype software is developed to refer the position of the aircraf...

The article describes the estimation of covariance parameters in Least Squares Collocation (LSC) by Leave-One-Out (LOO) validation, which is often considered as a kind of cross validation (CV). Two examples of GNSS/leveling (GNSS/lev) geoid data, characterized by different area extent and resolution are applied in the numerical test. A special atte...

Advantages and disadvantages of least squares collocation (LSC) and kriging have recently been discussed, especially as interdisciplinary research becomes popular. These statistical methods, based on a least squares rule, have infinite number of applications, also in the domains different than Earth sciences. The paper investigates covariance param...

The paper presents concept and preliminary results of the project concerning integration of GNSS/INS (Global Navigation Satellite System/Inertial Navigation System) positioning solution with combined SRTM (Shuttle Radar Topography Mission)/precise DEM (Digital Elevation Model) for air navigation. The project has been financed by National Science Ce...

W pracy przedstawiono metodykę pomiaru i opracowania obserwacji GPS dla zastosowań inżynierskich przy budowie autostrad. Pomiar osnowy realizacyjnej na odcinku 13 km dla obwodnicy Wyszkowa wykonano przy użyciu 7 odbiorników GPS: Ashtech Z-XII, Z-Surveyor oraz Z-Xtreme. Punkty osnowy realizacyjnej były w większości stabilizowane na skraju lasu, co z...

The area aid applications across the 25 EU member states cover almost 128 million hectares. According to EU regulations the area of agricultural fields must be checked against claims to ensure that farmers receive the right amount of subsidies. The checks are made with the use of remote sensing technology as well as with a great help of GNSS (Globa...

To enhance the accuracy of the geoid height in the project on a cm geoid in Poland, altimetry-derived, sea-borne and airborne gravity anomalies were used. The most reliable data is airborne data, because of high technology used like GPS, damped-platform type gravimeter and laser altimeter. Marine data characterizes by accuracy similar to airborne d...