Tomislav Bašić - Academia.edu (original) (raw)

Papers by Tomislav Bašić

IntechOpen eBooks, Sep 5, 2023

Numerical investigation on the importance of digital elevation models in regional geoid modelling

Investigation and comparison of RCR and LSMSA regional geoid modelling approaches

Development of Croatian Reference Frame

European geosciences union general assembly, 2004

The establishment of a new reference network of the Republic of Croatia through re-computation of... more The establishment of a new reference network of the Republic of Croatia through re-computation of international GPS campaigns carried out in 1994, 1995 and 1996 and recognising new solution within Resolutions of the EUREF Symposium in Dubrovnik in 2001 as combined EUREF-CRO94/95/96 solution for Croatia the required basis for further development of national reference frame was fulfilled. Also, the project Restoring of the Trigonometric Network of the II. order and Establishing the Homogenous GPS Network 10 x 10 km was finished in 2002. Following the EUREF recommendations, the ETRS89 will be accepted as new geodetic datum of the Republic of Croatia in a very near future. At State Geodetic Administration the Intranet database system of the geodetic points included all alpha-numerical and graphical data was finished at the and of 2003 with goal to enable access to data by way of Internet for all users till the end of year 2004. The new national gravimetric network included 42 first order points observed with SCINTREX gravity meters in 2003 will be conected to the national levelling and reference GPS network. Also, due to strategy of periodical controll of national reference GPS network, ten EUREF sites observed in 1994 will be re-observed in 2004.

Problems related to the Helmert's seven-parameter transformation

Prelaskom na novi položajni datum (ETRS89) i projekcijski referentni koordinatni sustav (ETRS89/T... more Prelaskom na novi položajni datum (ETRS89) i projekcijski referentni koordinatni sustav (ETRS89/TM ili HTRS96/TM), potrebno je transformirati i konvertirati prostorne podatke iz starog položajnog datuma (Bessel 1841) i projekcijskog referentnog koordinatnog sustava (HDKS/TM) u nove sustave. U Republici Hrvatskoj je oko 5% digitalnih prostornih podataka katastra oslonjeno na homogena polja koja su određena pomocu satelitskih metoda mjerenja. Za potrebe transformacije tih podataka u stari datum, svojevremeno su određeni parametri transformacije pomocu Helmertove sedam parametarske metode (Metoda koordinatnog okvira). Određen je cijeli niz županijskih, gradskih i drugih lokalnih parametara koji su implementirani u racunalni program Dat_Abmo, te se jos uvijek koriste kao službeni u RH. Zbog potrebe „vracanja“ prostornih podataka u ETRS89 položajni datum, koristenjem originalnih transformacijskih parametara, napravljena je analiza invertnih formula Helmertove 7-parametarske transformacije. Osim upotrebe invertnih formula, numericki su izracunani i invertni parametri (HDKS→ETRS89). Generirane su dvije rasterske mreže elipsoidnih koordinata, te je pretpostavljeno da su mreže izražene u ETRS89 položajnom referentnom koordinatnom sustavu. Testne položajne koordinate su transformirane u HDKS te potom „vracene“ natrag u ETRS89, s tri skupa originalnih i tri skupa numericki nanovo izracunanih parametara. Napravljena je analiza ulaznih i „vracenih“ ETRS89/TM projekcijskih koordinata te su prikazani rezultati.

A New Geopotential Model Tailored to Gravity Data in Europe

Springer eBooks, 1990

The European north-south GPS traverse was established to control and improve the European geoid. ... more The European north-south GPS traverse was established to control and improve the European geoid. Comparisons of GPS and levelling data with different geoid computations show a strong slope (1.5 m/700 km) between Denmark and Norway. This slope was suspected to be caused by bad quality of the up to now available 6′ × 10′ gravity values for Scandinavia. Therefore an updated set of 0.5° × 0.5° mean free-air gravity anomalies was calculated for Scandinavia. The new geopotential model (IFE88E2) has been calculated using this new set of 0.5° × 0.5° mean free-air gravity anomalies merged with other available 0.5° × 0.5° mean values for Europe. The calculation of the tailored model, complete to degree and order 360, is based on the OSU86F coefficient set, that was used as a start model. The RMS value of the differences between the 6715 mean values and the model derived values decreased from 15.8 mgal to 6.0 mgal for OSU86F resp. IFE88E2. The magnitude of residual point free-air anomalies relative to OSU86F and IFE88E2 were evaluated in 1495 points in Scandinavia. The RMS values of the differences were 23.4 mgal and 18.5 mgal respectively. Especially comparisons of the two models with GPS/levelling data in Europe show an improved accuracy of the IFE88E2 model. The RMS value of the differences relative to OSU86F is 0.774 m and decreases to 0.322 m for IFE88E2. Furthermore, the slope between Denmark and Norway has almost disappeared.

Anew about the correlation between Mohorovicic discontinuity depths, geoid undulations and Bouguer gravity anomalies in the Dinaric-Pannonian region of Yugoslavia

Geodesy and Physics of the Earth, 1985

Adria microplate motion and active deformation of the Dinarides - inferences from Global Positioning System (GPS) data

... Orientation of this “Adria Push” ranges from NNW-SSE in the Southern Alps of Slovenia towards... more ... Orientation of this “Adria Push” ranges from NNW-SSE in the Southern Alps of Slovenia towards the NNE-SSE direction in southern Dalmatia and in the Dinarides of Bosnia and Herzegovina. ... Research fields: Geodetics,Earth science. Printed media: da. CD/DVD media: da. ...

IntechOpen eBooks, Nov 9, 2022

Bathymetry underpins all marine and ocean research. It is common knowledge that there is a global... more Bathymetry underpins all marine and ocean research. It is common knowledge that there is a global deficit of high-resolution bathymetry based on modern acoustic techniques. Satellite altimetry enabled modeling of the global seafloor topography and revealed new morphological features in the unmapped areas of the oceans and seas. This chapter gives an overview of the physical problem and different approaches to estimating the bathymetry from satellite altimeter-derived gravity data. Characteristics of recent versions of frequently used global bathymetry models are presented. Moreover, this chapter demonstrates the possibility of regional bathymetry modeling by the gravity-geologic method in the Adriatic Sea.

IntechOpen eBooks, Apr 13, 2021

Radar satellite altimetry has revolutionized our understanding of the Earth's sea-level shape and... more Radar satellite altimetry has revolutionized our understanding of the Earth's sea-level shape and its change over time, monitoring of the natural and humaninduced water cycle, marine gravity computations, seafloor relief (bathymetry) reconstruction, tectonics, water mass balance change monitoring, etc., thus providing significant impact in geodesy. Today satellite radar altimetry is critical for unifying the vertical height systems, regional and global geoid modeling, monitoring of the sea level rise impact, monitoring of the ice sheet melting, and others. This chapter gives an overview of the technology itself and the recent developments including the SAR (Synthetic Aperture Radar) altimetry, coastal altimetry retracking methods, and new satellite missions (e.g. Sentinel-6). Besides, the chapter presents recent applied studies utilizing the altimeter data for ice sheet monitoring, vertical land motion estimating, bathymetric computations, and marine geoid modeling.

T7D versus T7 transformacija

Earth's Gravity Field Research at the Faculty of Geodesy

U radu se daje kratki povijesni pregled istraživanja Zemljinog polja ubrzanja sile teže u Hrvatsk... more U radu se daje kratki povijesni pregled istraživanja Zemljinog polja ubrzanja sile teže u Hrvatskoj, te detaljniji prikaz najznacajnijih poduhvata u zadnjih nekoliko godina u Zavodu za geomatiku Geodetskog fakulteta Sveucilista u Zagrebu. Pored prikaza najnovijih rjesenja za plohu geoida, donosi se osvrt na istraživanja u svrhu analize stanja i uspostavljanja nove Osnovne gravimetrijske mreže Republike Hrvatske, presudne za buduce ozbiljnije radove u ovom podrucju geodezije.

Geomagnetism in Croatia - a New Beginning

U radu se daje izvjesce stanja obnove geomagnetizma na podrucju Hrvatske, te kratki prikaz buduci... more U radu se daje izvjesce stanja obnove geomagnetizma na podrucju Hrvatske, te kratki prikaz buducih planova.

Quality control of topographic survey for the period 2002-2010

Državna geodetska uprava je nakon osamostaljivanja Republike Hrvatske zapocela s opsežnim projekt... more Državna geodetska uprava je nakon osamostaljivanja Republike Hrvatske zapocela s opsežnim projektom uspostave topografsko kartografskog sustava. Buduci da Topografske karte u izdanju Vojnogeografskog instituta iz Beograda nisu sustavno obnavljane u sadržajnom smislu zapocet je proces proizvodnje novih karata baziranih na vektorskim topografskim podacima. Prvi Ugovor za izradu karata potpisan je 1996. godine za podrucje Istre i obuhvacao je ukupno 20 listova. Također je zapoceta i proizvodnja digitalnih ortofoto karata u mjerilu 1:5000 zasnovana na ciklickim aerfotogrametrijskim snimanjima. Buduci da u to vrijeme nisu postojale službene procedure za proizvodnju pokrenute su aktivnosti i donesen je Pravilnik o nacinu topografske izmjere i o izradbi državnih zemljovida (NN 55/2001). Zakonom o državnoj izmjeri i katastru nekretnina (NN 128/1999) te osnivanjem Hrvatskog geodetskog instituta zapocet je proces obavljanja kontrole kvalitete na institucionalnoj razini. U to vrijeme procedure kontrole kvalitete nisu bile zasnovane na međunarodnim normama (ISO), sustav kontrole kvalitete u Institutu je bio zasnovan na potpunoj ili cjelovitoj kontroli kvalitete. Nakon zavrsetka hrvatsko-norveskog geoinformacijskog projekta (CRONO GIP) primjenjuju se metode kontrole kvalitete zasnovane na ISO normama. U radu su kronoloski predstavljeni rezultati kontrole kvalitete glavnih proizvoda topografske izmjere (DOF, TK25, Topografski vektorski podaci) od 2002. godine do danas s pokazateljima kolicine obavljenih radova po godinama, kriterijima za prihvacanje i odbijanje, primjerima nalaza kontrole kvalitete te prijedlozima i preporukama za daljnje poboljsanje kvalitete proizvoda, sustava kontrole kvalitete i specifikacija proizvoda u nadležnosti Državne geodetske uprave.

Latest study of Adriatic microplate over the territory of Republic of Croatia

Comparison of combined solution of Croatian Positioning System (CROPOS) and positioning systems o... more Comparison of combined solution of Croatian Positioning System (CROPOS) and positioning systems of neighboring countries (Slovenia - SIGNAL, Hungary - GNSSnet.hu and Montenegro - MontePOS), computed from 1741 daily solutions (ETRF2000, e2011.31) for the time span of ~ 5 years with the first adjustment of CROPOS network (GPSW 1506, ETRF2000 (R05), e2008.83) indicates to long-term stability of CROPOS reference frame. Relative kinematic model of Adriatic tectonic microplate CROvel, computed from GPS measurements of CROPOS and nearby positioning systems doesn't show agreement with results of previous researches because this model is calculated for a very short time period, while absolute kinematic model of research area (as a part of Eurasian plate) CRO-2014 shows agreement with global kinematic models and gives a possibility of using this model for point velocity calculation over the territory of Croatia. Geodynamic measuring campaigns allow continuous monitoring of tectonic displacements. Relative kinematic model of Adriatic microplate ADRIAvel, calculated from GPS measurements obtained from 17 geodynamic campaigns (time span of 20 years) shows agreement with results of previous researches, while absolute kinematic model of research area CRODYN-2014 shows agreement with global kinematic models as well and also can be applied for point velocity calculation over the territory of Croatia. Relative kinematic model of Adriatic microplate CroADRIAvel as a result of combination of 1741 daily solutions of CROPOS and nearby positioning systems for time span of ~ 5 years with 17 GPS geodynamic campaigns shows (time span of 20 years) agreement with results of previous researches, while combined absolute model of research area GEODYN-2014 also shows agreement with global kinematic models.

The contribution of the GRAV-D airborne gravity data in the regional geoid modelling: a case study in Colorado, USA

Geomorphometric and drainage network models of the territory of Republic of Croatia

Geozezija - tippfehler ili?

On Development of the Croatian Offshore Vertical Reference Frame

Geodetski List, Dec 30, 2017

SAŽETAK. Radarska satelitska altimetrija metoda je prikupljanja globalnih visokopreciznih podatak... more SAŽETAK. Radarska satelitska altimetrija metoda je prikupljanja globalnih visokopreciznih podataka o razini mora u odnosu na odabrani geocentrični referentni okvir. Opažanja satelitskom altimetrijom omogućuju određivanje oblika i veličine Zemlje te računanje Zemljina polja ubrzanja sile teže što su i osnovne geodetske zadaće zadane definicijom geodezije. Mjerenja promjene srednje razine mora prikupljena satelitskom altimetrijom služe kao izravni pokazatelj djelovanja klimatskih promjena i drugih geofizičkih procesa na Zemlji, a primijenjena su i za definiranje visinskih sustava na kopnu i moru, izradu karata dubina, procjenu vertikalnih gibanja obalnih područja i sl. U ovom radu detaljno je prikazan osnovni koncept tehnologije uz primijenjene principe obrade radarskih opažanja. Poseban je naglasak na prikazu i analizi korekcija altimetrijskih opažanja potrebnih zbog propagacije signala kroz atmosferu te utjecaja geofizičkih fenomena vodenih površina na odaslani signal. Rad detaljno prikazuje razvoj tehnologije kroz tri faze uz analizu doprinosa svake te opisuje smjernice budućeg razvoja tehnologije. Naposljetku, prikazani su proizvodi satelitske altimetrije dostupni za primjenu u geodetske svrhe kao što su modeli anomalija ubrzanja sile teže, dubina, trendova srednje promjene razine mora i drugi. Ključne riječi: satelitska altimetrija, promjena razine mora, obalna altimetrija, prostorni podaci.