Papers by Janis Kaminskis
Geodesy and cartography, Apr 12, 2024
The article describes the sources of geomagnetic data, the reduction of geomagnetic data for the ... more The article describes the sources of geomagnetic data, the reduction of geomagnetic data for the territory of Latvia to the epoch 2021.5, the history of previous magnetic observations in Latvia, the information available in the State Geodetic Network database and the information available in the World Geomagnetism Data Centre. The sequence of absolute measurements is described in detail. To visualise the changes in the magnetic declination value in the territory of Latvia, a 2021.5 year declination fluctuation has been created using ArcGIS Pro. The declination values in Latvia range from 6.68° to 10°, the inclination values range from 71.089° to 72.245° and the total magnetic field values from 51100 nT to 52594 nT. The values obtained for the magnetic field components refer to a magnetically clean environment, and there can be, and are, differences in the natural conditions in the Latvian territory, in natural anomalous locations and in locations with artificially high magnetic field noise (e.g. in cities, near railways, near high voltage lines, etc.). In the Latvian network, points have been selected in locations where the magnetic noise is minimal, as this is the technological process for building such stations. Magnetic observatories are even stricter, so the data coming from the observatories reflect the natural magnetic field without the influence of magnetic anomalies. The reduced magnetic field values and their representation on a map can be used for aeronautical navigation, military applications, identification of local magnetic anomaly sites or search for magnetically clean environments.
Computers and Electronics in Agriculture, 2000
Global positioning systems first became available for private use in 1995. Since the introduction... more Global positioning systems first became available for private use in 1995. Since the introduction of NAVSTAR-GPS (Navigation System with Time and Ranging -Global Positioning System) and GLONASS (Globaluaya Navigatsionnaya Sputnikovaya Sistema, Global Navigation Satellite System), such systems have quickly become indispensable in a wide range of applications. Above all, GPS is used today by a large user community. Artificial augmentations can be used to improve the performance of the systems in terms of accuracy, availability and integrity. In space-based augmentations, differential correction data, integrity information and additional ranging signals are transmitted from geostationary satellites. In ground-based augmentations, a reference station (based on a geo-referenced position) compares the position solution (calculated by the SatNav System) with the real coordinates. In that case, the correction data is transmitted by a telemetric system to roving receivers near the reference station. Both augmentation techniques are based on the generic satellite navigation systems GPS or GLONASS, and are dependent on the availability of the source system. To overcome the dependency of the civil European user community upon foreign military systems, an initiative to build up an autonomous European Satellite Navigation System with an own-space segment was initiated. Since 1999, the realisation of this project has been on the way, and the employment of the new system, named Galileo, is currently expected in 2008.
Global navigation satellite system adoption in Latvia
EGS - AGU - EUG Joint Assembly, Apr 1, 2003
We have tested together one permanent and two semi permanent GPS base stations with separations i... more We have tested together one permanent and two semi permanent GPS base stations with separations in between stations up to 50km in Riga urban region and achieved good results. Our aim is to distribute differential GPS and later on RTK corrections to end-users all over Latvia. We participate into European Position Determination system (EUPOS) activities, too. On the base of
Development of Permanent GPS Network In Latvia
EGSGA, 2002
State Land Service of Latvia, together with potential users, University of Latvia and Riga Techni... more State Land Service of Latvia, together with potential users, University of Latvia and Riga Technical University is working on project "Development of permanent GPS net- work in Latvia" aimed to distribute differential GPS and RTK signals (corrections) to end users. The general principles of base stations distribution, communication prob- lems as well as software and processing solutions are going under
Analysis of Kinematic Coordinates from GNSS Stations in Latvia
Latvian Journal of Physics and Technical Sciences, Aug 1, 2022
Throughout the centuries, Riga has been the city with dynamic development. Its territory has unce... more Throughout the centuries, Riga has been the city with dynamic development. Its territory has unceasingly expanded, whereby previously unused territories have been urbanized. Managers of the city understood already at the end of 19th century that unified geodetic network had great importance in the development of the city. Since then, Riga's local geodetic network has evolved with the city, several coordinate and height systems have been replaced, but the task has remained the same-to provide a flawless, homogeneous geodetic foundation for various surveying activities. In 2018, the development of the local geodetic network in several parts of the city was completed, whereby the problem arose-altitude values of surveyed terrain points determined by using the improved geodetic network did not coincide with altitude values determined using the GNSS method. Considering the above-mentioned problem, the objectives of this study were set: to plan and carry out control measurements of the improved local geodetic network in the vicinity of Grizinkalns, to provide analysis of the obtained results and recommendations for further development of a local geodetic network. The difference between the heights determined by the geometric levelling method and the heights determined by the GNSS method shall not exceed 2 mm. According to the GNSS method, using the quasi-geoid model LV'14 v2, the determined heights of the geodetic grid points differ from the given ones by 0.062 m on average. The differences are systematic. To overcome these differences, the quasi-geoid model needs to be refined.
Already after our independence in the nineties of the twentieth century, we used common height sy... more Already after our independence in the nineties of the twentieth century, we used common height system-Baltic Normal height system 1977 (BHS 1977). Latter we have made big job for verification and modernization of our geodetic network in the frames of different international campaigns. There we always cooperating with Nordic countries in frames of Nordic Geodetic Commission (NKG). Also we have had sector programme between Denmark and Baltic countries about modernization of geodetic network. Already in that time we carried out common work in the field of gravity survey, levelling and GNSS observation. As European Union member states-Latvia and Lithuania have changed their national height systems to European Vertical Reference System realizations. Latest product of such efforts, we have freely available latest Nordic quasi-geoid model NKG2015, too. For studies of height network consistency in regional and international level we carry out GNSS observation campaigns and making comparison of the obtained survey results and computed ones from different geoid models, for example LV98, NKG2015, EGG2015 etc. In such way, we are making conclusions about quality of geodetic network and giving recommendation for the future work. The aim of the research is using GNSS measurements gain insight for methodology development of geodetic point height testing. To achieve the aim following tasks were set: 1) perform GNSS measurements of first order levelling network points in Latvia and Lithuania; 2) to do data processing to get station coordinates; 3) to compare point elevations. For GNSS measurements use for height determination it is very significantly to use advanced measuring technologies and verified data processing methodology. RMS errors describe high accuracy of performed measurements.
Astronomer and Metrologist Fricis Blumbahs (1864–1949)
publication.editionName, 2015
Kvaziģeoīda reģionālā modeļa pilnveidošanas procesa novērtējums Latvijā
Nekustamais īpašums un ekonomikas attīstība: zinātnes un prakses sinerģija, 2019
Kurzemē dzimušais astronoms Fricis Blumbahs (1864-1949)
Ventspils Augstskolas Inženierzinātņu institūtam VSRC 20, Chapter: Kurzemē dzimušais astronoms Fr... more Ventspils Augstskolas Inženierzinātņu institūtam VSRC 20, Chapter: Kurzemē dzimušais astronoms Fricis Blumbahs (1864-1949), Publisher: Ventspils Augstskolas Inženierzinātņu institūts Ventspils starptautiskais radioastronomijas centrs, Editors: Dr.chem. Valdis Avotiņš
On road of" EUPOS contribution to GOCE mission
The ground based augmentation system EUPOS® is widely used for land surveying where the height co... more The ground based augmentation system EUPOS® is widely used for land surveying where the height component is substantial. The high quality geoid model for normal or orthometric height determinatian is needed. Therefore EUPOS® community is willing to support the European Space Agency (ESA) Gravity and solid state Ocean Circulation Explorer (GOCE) mission which aims to 1-2 cm precision geoid model determination. The project proposal ”EUPOS® contribution to GOCE mission” has been accepted by ESA. However, accomplishment of EUPOS® liabilities in this project are rather sporadic due to the professional daily responsibilities of the corresponding organizations of EUPOS® partner countries. In spite of this we are trying to improve our activities in contribution to GOCE mission
Ulaanbaatar Qgeoid Computation, Parameter Estimation and Optimization Concepts for Gravity Field Determination
ULAANBAATAR QGEOID COMPUTATION, PARAMETER ESTIMATION AND OPTIMIZATION CONCEPTS FOR GRAVITY FIELD ... more ULAANBAATAR QGEOID COMPUTATION, PARAMETER ESTIMATION AND OPTIMIZATION CONCEPTS FOR GRAVITY FIELD DETERMINATION K Morozova1,2, R Jaeger3, M Saandaar4, G Silabriedis1, J Balodis1 and J Kaminskis1,2 1Institute of Geodesy and Geoinformatics, University of Latvia 2Department of Geomatics, Faculty of Building and Civil Engineering, Riga Technical University 3Institute of Applied Research (IAF), Hochschule Karlsruhe – University of Applied Sciences 4MonMap Engineering Services Co., Ltd
Latvijas Republikas pirmās klases ģeodēziskā tīkla mērījumu analīze
Digital Zenith Camera – a New Astrometric Instrument for Precision Measurements in Geodesy
Detailed knowledge of local geoid surface has become increasingly important in order to fully use... more Detailed knowledge of local geoid surface has become increasingly important in order to fully use the potential of accurate geocentric positions, provided by GNSS. Recent advances in a number of scientific and technological fields – accurate astrometric reference star catalogs, development of digital imaging technology, high accuracy tiltmeter technology, and geocentric coordinate availability using GNSS – have made it possible to use astrometric methods for accurate, fast and automated determination of vertical deflections. Such measurements can give important contribution in determination of local geoid properties. Zenith cameras for this kind of measurements have been developed by several research groups. However, accessibility to these instruments is limited. The institute of Geodesy and Geoinformatics of the University of Latvia has engaged in a project to develop its own digital zenith camera that is portable and reliable using off-the-shelf components as much as possible
Case Study: One Centimeter Precision Regional Quasi-Geoid
— an attempt has been made to develop the one centimeter precision regional quasi-geoid model for... more — an attempt has been made to develop the one centimeter precision regional quasi-geoid model for transformation of the ellipsoidal GNSS height, h, to the standard height, H. For this purpose the densification of the GNSS/levelling point regional network has been performed in Latvia. Differential GNSS processing strategy, IGS/EPN reference station network and Helmert transformation 7 parameter method used to reduce the daily results of Latvian continuously operating station network to the ETRS89 fixed epoch. The same Helmert transformation 7 parameters are applied for the corresponding date GNSS/levelling point ellipsoidal height reduction to the same fixed epoch in order to avoid the daily unresolved network deformations. The new geoid model based on LAS-2000,5 normal height system, ellipsoidal heights and global gravimetric models (EGG97 and EGM2008) was computed using DFHRS v 4.0 software.
This research presents a quasi-geoid model for the Western part of Latvia based on parametric mod... more This research presents a quasi-geoid model for the Western part of Latvia based on parametric modelling of continuous polynomial surface by DFHRS (Digital Finite-element Height Reference Surface) software v.4.3 developed by Hochschule Karlsruhe – University of Applied Sciences. Apart from standard observations for quasi-geoid determination – GNSS/levelling points and Global Geopotential Models (GGMs), new kind of measurements – astrogeodetic vertical deflection (VD) observations provided by Digital Zenith Camera (DZC) are used. This instrument has been developed by the Institute of Geodesy and Geoinformatics, University of Latvia (GGI) and provides the accuracy of about 0.10 arcsec, what equivalent to 0.5 mm error in elevation for 1 km length and it gives two times better accuracy than 1st order levelling in Latvia respectively. 44 1st order GNSS/levelling points were observed by GGI staff and 27 1st order levelling points were provided by Latvian Geospatial Information Agency (LGIA...
Apvienotais Latvijas gravimetriskais ģeoīds
Darbā ir aprakstīts gravimetrisko datu ciparošanas process, kura laikā bija jāsaskaras ar atšėirī... more Darbā ir aprakstīts gravimetrisko datu ciparošanas process, kura laikā bija jāsaskaras ar atšėirīgu un neviendabīgu vēsturisko datu noklājumu. Rezultātā iegūtie izejas dati bija nepilnīgi, jo īpaši uz Baltijas jūras. TamdēĜ situācijas uzlabošanai bija nepieciešams izmantot ZMP ERS-1 altimetriskos mērījumus, kurus pārrēėināja par gravimetrijas datiem. Pēc minēto izejas datu iegūšanas un analīzes nākošajā darba posmā ar speciālo programmu GRAVSOFT tika aprēėināts valsts gravimetriskais ăeoīds vairākās kombinācijās. Salīdzinot dažādus ăeoīda modeĜa risinājumus, kuros lietots atšėirīgs gravimetrisko datu apjoms, secinām ka altimetrisko datu iekĜaušana ăeoīda modelēšanā mums sniedz precizitātes uzlabojumu par 1.3 cm
Globālās navigācijas satelītu sistēmas
Grāmata satur divas daļas: I Teorija un metodes II Pielietojumi Ģeodēzijā Pirmā daļā ietverta inf... more Grāmata satur divas daļas: I Teorija un metodes II Pielietojumi Ģeodēzijā Pirmā daļā ietverta informācija par GNSS sistēmām, signāliem, koordinātu sistēmām un mērīšanas metodēm. Otrā daļā atspoguļoti GNSS pielietojumi ģeodēzijā – ģeodēziskie tīkli, ģeoīds un GNSS praktiskie mērījumi, arī ar LatPos sistēmu
Research of National Geodetic Network in Baltic using GNSS Methods
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Papers by Janis Kaminskis