Preliminary results of combined geodetic methods in monitoring

Abstract

Subject reviewThe actual object movements can be examined by well designed and carefully performed observations and measurements. The processed and adjusted data are a precondition for analysis and interpretations of short and long-term predictions of object functionality. Beside periodic deformation observations, experimental measurements could be performed on selected objects. The purpose of such work is to determine the accuracy and improve the applied methods of measurement based on the analysis of theoretical errors and actual values of the facility shifts on a daily basis. On the business tower "Zagrepčanka" the GNSS measurements in relation to the nearest reference station from CROPOS (Croatian Positioning System) network were performed, combined with geometric levelling and gravity measurements. Analysis of measurement results that are presented in this paper provides an answer to the question to what extent one method can be controlled by another, or to what extent the application of a combination of different surveying methods affects the quality of the interpretation of the results. Keywords: deformations; GNSS; gravity; levelling; shifts Preliminarni rezultati kombiniranih geodetskih metoda u monitoringuPregledni članak Stvarno ponašanje objekta može se ispitati samo dobro osmišljenim i brižljivo izvedenim opažanjima i mjerenjima te na osnovu toga obradom i izjednačenjem mjerenja što je preduvjet za izvođenje analize i interpretacije kojom se daju kratkoročne ili dugoročne prognoze funkcionalnosti objekta. Pored periodičnih opažanja pomaka, izvode se i eksperimentalna mjerenja na odabranim objektima. Svrha takvih radova je u određivanje točnosti i poboljšanju primijenjenih metoda mjerenja na bazi analize teorijskih pogrešaka i stvarnih veličina pomaka na dnevnoj bazi. Eksperimentalna mjerenja na poslovnom tornju Zagrepčanka obuhvatila su GNSS mjerenja prema najbližoj referentnoj stanici iz CROPOS mreže, u kombinaciji s geometrijskim nivelmanom i gravimetrijskim mjerenjima. Analiza rezultata mjerenja koji su prikazani u ovom radu daje odgovor na pitanje u kojoj mjeri jedna metoda može kontolirati drugu, odnosno u kojoj mjeri primjena kombinacije različitih geodetskih mjerenja utječe na kvalitetu interpretacije rezultata.

Synchronisation of Contactless Vibration Monitoring Methods

“…The results of the contactless vibration measurement methods used should be compared with each other, as presented in [15,17]. Recently, many authors [18][19][20][21][22][23][24][25] have dealt with the use and accuracy of GNSS-derived results and ground-based scanners and ground-based radar interferometry [26] in determining the dynamic response and in various types of object monitoring.…”

A Comparative Study of Signal Processing Methods for Contactless Geodetic Monitoring

“…To better understand the behavior of the structure, it is reasonable to perform measurements with different independent non-contact methods and compare the results, as presented in [22]. Recently, many authors [23][24][25][26][27][28][29][30] have been concerned with the use and accuracy of the results obtained with GNSS and terrestrial scanners in the determination of the structural response and in various types of object monitoring.…”