DOLOČITEV POLOŽAJEV CERKVENIH ZVONIKOV V KOORDINATNEM SISTEMU D96/TM.

POSITION DETERMINATION OF CHURCH BELFRIES IN THE D96/TM COORDINATE SYSTEM.

In the old coordinate system, church belfries often served as reference points in detail surveying, so their coordinates were regularly maintained in the geodetic databases. Their usability was reduced by the new coordinate system establishment along with the use of satellite based positioning methods. Today they have gained at their practical value since the trigonometric geodetic points decrease due to reconstructions. They were mostly preserved in the original condition, so they present the possibility of transition from the old to the new coordinate system. They serve for the transformation parameters' determination as well as for the quality evaluation of the state transformation model. For this, their coordinates should be determined in the new coordinate system. The article describes the determination of five church belfries from south-western part of Ljubljana in the new coordinate system D96/TM. The procedure combines geodetic network datum determination, inclusion of the terrestrial measurements and free-network adjustment and further use of the S-transformation. Further comparison of coordinates shows some centimetre differences for the given sample of church belfries. For the sample under consideration, we can conclude that the Slovenian triangle-based transformation model effectively describes transformation between the old and the new coordinate system. [ABSTRACT FROM AUTHOR]

Cerkveni zvoniki so v starem koordinatnem sistemu v veliko primerih služili za izhodišče izmere, zato so njihove koordinate redno vzdrževali v geodetskih bazah. V novem koordinatnem sistemu ob uporabi satelitskih metod izmere ter transformacij med koordinatnimi sistemi so izgubili na uporabni vrednosti. Ker se danes število talnih točk starih trigonometričnih mrež zaradi rekonstrukcijskih del zmanjšuje, zopet pridobivajo na pomenu. V večini primerov so ohranjeni v prvotnem stanju, zato predstavljajo možnost zveznega prehoda med starim in novim koordinatnim sistemom. Uporabimo jih lahko za določitev transformacijskih parametrov ali za oceno kakovosti vsedržavnega modela transformacije, vendar jim moramo pred tem koordinate določiti v novem koordinatnem sistemu. V prispevku opisujemo določitev položajev zvonikov petih cerkva na območju jugo-zahodne Ljubljane v koordinatnem sistemu D96/TM. Postopek združuje določitev datuma geodetske mreže z meritvami GNSS, terestrično izmero in izravnavo proste mreže ter uporabo S-transformacije za vklop izravnane terestrične mreže v koordinatni sistem D96/ TM. Koordinate smo primerjali s transformiranimi (trikotniška transformacija) in ugotovili razlike reda velikosti nekaj cm. Za obravnavani vzorec točk lahko rečemo, da model vsedržavne trikotniške transformacije učinkovito opisuje prehod iz starega v novi koordinatni sistem. [ABSTRACT FROM AUTHOR]