Danijel Šugar

CROATIAN GEOMAGNETIC REPEAT STATIONS NETWORK

Prikazana je uspostava mreže primarnih sekularnih geomagnetskih tocaka na teritoriju Republike Hrvatske. Tocke za istraživanje sekularne varijacije projektirane su sukladno preporukama Coordination Committee for Common European Repeat Station Surveys, kriterijima International Association of Geomagnetism and Aeronomy – IAGA te iskustvima europskih zemalja. Konacne lokacije sekularnih tocaka izabrane su evaluacijom kriterija na samom terenu. U tu svrhu razvijene su i testirane metode određivanja gradijenata totalnog intenziteta ukljucujuci potrebnu programsku podrsku. Iz ispitivanja razlicitih materijala uslijedio je izbor kamene stabilizacije. Tocke mreže stabilizirane su ukopavanjem stabilizacije standardnim geodetskim postupcima. Status svake tocke mreže dokumentiran je obrascima Položajnog opisa i Geomagnetskih parametara.

GEOMAGNETIC SURVEY ON SINJSKO POLJE REPEAT STATION AND DATA REDUCTION USING THE ONSITE dIdD VARIOMETER

Within the Croatian-Hungarian project for the first time in the Republic of Croatia the repeat stations survey was carried out using an onsite dIdD (delta Declination / delta Inclination) variometer. Since the geomagnetic field vector observations are obtained in the instrument’s reference frame, the calibration parameters have to be determined enabling the transformation to the geographic coordinate system XYZ. Three and a half days long occupation of the Sinjsko polje (SINP) repeat station revealed the temporal variability of the geomagnetic field gradients. Although observations were affected by an extra magnetic field contributions, the determination of the quiet-time level geomagnetic field differences between the SINP repeat station and THY (Tihany) reference observatory enabled a more reliable data reduction. The comparison of results of different data reduction methods pointed out the improvement of the geomagnetic survey with the onsite variometer.