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Dive into the research topics where Mladen Zrinjski is active.

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Featured researches published by Mladen Zrinjski.


13th SGEM GeoConference on INFORMATICS, GEOINFORMATICS AND REMOTE SENSING | 2013

Laboratory Procedure for the Calibration of Laser Handheld Distance Meter

Đuro Barković; Mladen Zrinjski; Božica Borić

The paper describes the laboratory procedure for the calibration of laser handheld distance meter Leica DISTO needed for certificate issuance. Testing and calibration was done in the Laboratory for Measurements and Measuring Techniques at the Faculty of Geodesy, University of Zagreb. The testing procedure is intended for making technical assessment of the device, and the calibration procedure for the quality assessment of the device. There is a calibration base set up in the laboratory for the purpose of calibration consisting of ten station points with total distance of 40 m. The tripod footholds are the points that are anchored with special screws in the concrete base to make the tripods stable during the measurement. The measurements have been made in a short time interval with reference, as well as with operating device. The reference measuring device was a precise measuring station Leica TCA2003, and the operating measuring device was the laser handheld distance meter Leica DISTO. With the reference measuring device, a precise prism Leica GPH1P was used, and with the operating measuring device a white reflex plate was used as a target surface. The prism and the target surface were set up on the tripods with the possibility of constrained centring and levelling up. There were 10 distances in altogether 30 measurements measured with each device. Out of the measurement data, the measuring uncertainty of the device Leica DISTO, U = 3.8 mm was calculated along with the coverage factor k = 2 and the reliability level of about 95%. Based on the testing and calibration of the laser handheld distance meter Leica DISTO, the certificate of the accredited laboratory was issued, which confirmed its proper operation in technical sense, as well as related to quality compared to the information given by the manufacturer of the device.


16th International Multidisciplinary Scientific GeoConference SGEM2016 | 2016

Testing the Precision of Robotic Total Stations on the Test Area

Đuro Barković; Mladen Zrinjski; Nikola Predović

The measuring precision of horizontal and vertical angles has been tested by means of three geodetic total stations in the test area. The measurements have been done with the robotic total station Trimble S6, the robotic total station Trimble VX and autolock total station Trimble S6. The test area was arranged in the quarry Plaskarica near the town Ogulin in Croatia. It consists of a station point, three orientation points and nine sighting points. The sighting points were arranged at three levels under various elevation angles and at various distances from the station point. The sightings were performed at nine prisms, at each level on three various types of prisms. The measurements were repeated several times and in various weather conditions. The testing results indicate that the obtained measuring precisions of horizontal and vertical angles with three total stations are within the scope of values defined by the manufacturer of the instruments.


14th SGEM GeoConference on INFORMATICS, GEOINFORMATICS AND REMOTE SENSING | 2014

AUTOMATION OF TESTING OF GEODETIC MEASURING INSTRUMENTS

Đuro Barković; Mladen Zrinjski; Dino Udovičić

International and national standards for testing and calibration of geodetic measuring instruments specify the procedures of testing and calibration, as well as the presentation of measurements results with the estimation of measuring uncertainty. The paper presents only the international standards for testing and calibration of geodetic measuring instruments because the national standards are identical to original international standards. The paper includes the automation procedures of testing the precision of the following geodetic measuring instruments: levels according to the standard ISO 17123-2:2001, theodolites according to ISO 17123-3:2001, and GNSS RTK measuring system according to ISO 17123-8:2007. For the purpose of automating the testing of the precision of geodetic measuring instruments according to the above mentioned standards, the computer programme GeodISO has been prepared, using modern programme language C#. This programme provides the processing of measurement data, the performance of adequate statistical tests and the preparation of test reports.


SGEM2011 11th International Multidisciplinary Scientific GeoConference and EXPO | 2011

Determination of Pillar Coordinates at the Calibration Baseline of the Faculty of Geodesy in Zagreb by Applying GPS

Mladen Zrinjski; Đuro Barković; Marko Kapustić

The calibration baseline of the Faculty of Geodesy, University of Zagreb, is the longest calibration baseline in the world numbering altogether 25 pillars. It was built in 1982 for the purpose of testing and calibrating the electro-optical distance meters, and today even GNSS instruments can be tested there. This calibration baseline provided a mutual standard scale for the calibration of instruments at the distance up to 3100 m in the Republic of Croatia and wider region. In this paper the determination of coordinates of all 25 pillars of the calibration baseline of the Faculty of Geodesy, University of Zagreb by applying of relative static GPS method is described. GPS method is used as an independent control in the calibration of the baseline with precise electro-optical distance meters. GPS measurements at the pillars of the calibration baseline were made in two days with the observation interval of 30 minutes for each pillar. The processing of GPS vectors and the adjustment of coordinates of the baseline pillars were made using the software Trimble Geomatics Office, v. 1.62. For the purpose of adjusting the coordinates, 2 GPS points of the Fundamental network of the City of Zagreb were used. As the final result the coordinates of the calibration baseline pillars were given in ETRS89 (European Terrestrial Reference System 1989), epoch 1989.00 (e=1989.00).


15th International Multidisciplinary Scientific GeoConference SGEM2015 | 2011

Testing the Precision of GNSS RTK Measuring Systems by Applying of Computer Programme

Mladen Zrinjski; Đuro Barković; Marija Herent

The paper gives the overview of the standard ISO 17123-8:2007. It presents the field procedure of testing the precision of GNSS RTK measuring systems according to the full test of the mentioned standard. The computer programme GNSS_RTK_ISO has been developed for testing the precision of GNSS RTK measuring systems. The testing of the precision of RTK measuring system Trimble R8 GNSS has been made at the calibration baseline of the Faculty of Geodesy, University of Zagreb. The measuring data are the coordinates and orthometric height. The testing results referring to the precision of GNSS RTK system are indicated with empirical standard deviations. The statistical testing of obtained results has been made according to four statistical tests in order to determine the quality of measuring data for the tested measuring system. The results obtained in testing show that the RTK measuring system Trimble R8 GNSS is correct, and the calculated empirical standard deviations are smaller than the related values declared by the manufacturer of the instrument.


Survey Review | 2010

Geodetic Basis of the Longest Tunnel in the Republic of Croatia

Mladen Zrinjski; Marko Džapo

Abstract The tunnel “Mala Kapela”, 5760 m long, is the longest tunnel in the Republic of Croatia. This paper gives the presentation and the analysis of the geodetic basis in the tunnel “Mala Kapela”. The tunnel geodetic basis consists of the overhead and underground part. The overhead geodetic basis consists of: 1. two geodetic rectangles (one in the vicinity of the northern, and the other in the vicinity of the southern portal) 2. a precise traverse connecting positionally these two micro-networks 3. a precise levelling figure connecting vertically the micro-networks of the northern and southern portals. The underground geodetic basis consists of: 1. two networks in the right tunnel tube in the form of a triangle chain (one of them at the northern, and the other at the southern tunnel portal) 2. two traverses in the left tunnel tube (one of them at the northern, and the other at the southern part of the tunnel) connecting the underground networks in the right tunnel tube and the overhead geodetic basis at the northern, i.e. the southern portal of the tunnel 3. two closed precise levelling figures (one at the northern and the other one at the southern part of the tunnel). This is the first time that an underground geodetic basis in the form of a triangle chain has been applied in the Republic of Croatia. It was chosen because it best meets the set criteria related to the accuracy of cutting the tunnel “Mala Kapela”. The error sources in direction measurement were processed with special attention given to the error of the initial grid bearing and direction orientation. The article gives an outline of formulas used to calculate corrections and reductions of the lengths measured with electro optical distance meter. At the end, there is an illustration of the accuracy of cutting the tunnel “Mala Kapela”. The transverse deviation for the cutting point in the right tunnel tube was sQ = 0.8 cm and the longitudinal deviation sL = 2.1 cm. The transverse deviation for the cutting point in the left tunnel tube was sQ = 1.0 cm and the longitudinal deviation sL = 2.2 cm. The vertical deviation for the cutting point in the right tunnel tube was sH = 1.9 cm, and for the cutting point in the left tunnel tube sH = 2.1 cm.


Geodetski List | 2009

GPS-antenna Zephyr Geodetic

Nikola Solarić; Miljenko Solarić; Mladen Zrinjski


Geodetski list : glasilo Hrvatskoga geodetskog društva | 2011

New Technological Achievement in the Construction of Integrated Measuring Stations

Nikola Solarić; Miljenko Solarić; Đuro Barković; Mladen Zrinjski


Treći hrvatski kongres o katastru s međunarodnim sudjelovanjem | 2005

European Spatial Data Infrastructure

Mladen Zrinjski; Đuro Barković


Zbornik radova Građevinskog fakulteta | 2018

GEODETSKI RADOVI ZA POTREBE INDUSTRIJSKE ZONE LONIĆI U HRVATSKOJ

Đuro Barković; Mladen Zrinjski; Sergej Baričević; Luka Basa

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