Geodetski Vestnik (Jan 2009)
Mozaičenje listov kart merila 1 : 75.000 tretje vojaške izmere avstro-ogrske : Mosaicking the 1:75,000 maps of the third military survey of the Austro-Hungarian Empire
Abstract
SI: Originalnih listov sistemskih kart tretje vojaške izmere avstro-ogrske monarhije zaradi trapeznega formata ne moremo stično mozaičiti v ravnini. Če želimo izdelati digitalni mozaik listov, jih moramo transformirati, in če jih želimo uporabiti hkrati z drugimi podatki v GIS-u, jih moramo tudi georeferencirati. Namesto originalnih projekcij, ki so na vsakem listu drugačne, smo definirali niz sinusoidnih projekcij, in sicer enotne projekcije za vsak posamezen stolpec listov. Sinusoidna projekcija omogoča primeren približek za prvotne trapezaste oblike in je primerna glede na dejansko velikost listov. Vsak list je bil nato rektificiran (izravnan) v ustrezno projekcijo in nato preprojiciran v splošno stožčno projekcijo, definirano za končen mozaik. Po izvedbi vseh operacij se digitalna vsebina listov medsebojno dovolj dobro ujema za izdelavo georeferenciranega mozaika. Lokacijski parametri geodetskega datuma, uporabljeni za transformacijo v današnji koordinatni sistem, so naslednji: dX = +600 m, dY = +205 m, dZ = +437 m. Ti podatki omogočajo točno in natančno ujemanje s fundamentalno točko na Hermannskoglu. Zara i neenotne izravnave (neuporabe enotnega datuma) celotnega sistema geodetskih točk so v modernem usklajenem modelu posamezna območja in torej tudi sistemske karte monarhije lokalno-sistematično uravnani z zamikom do 220 metrov. EN: The original map sheets of the third military survey of the Austro-Hungarian Empire cannot be mosaicked in their original, printed form as their format is uneven and trapezoidal. To make a digitized raster mosaic of individual sheets, they should all be transformed, as well as georeferenced for applications in GIS. Instead of the original projections, which vary from sheet to sheet, a series of sinusoid projections was defined, one unique projection for each sheet column. The sinusoid projection provides an appropriate approximation of the original trapezoid forms and size of the sheets. Each sheet was rectified in the respective projection MOZAIÈENJE LISTOV KART MERILA 1 : 75.000 TRETJE VOJAŠKE IZMERE AVSTRO-OGRSKE and then reprojected to a general conic projection, defined for the final mosaic. After all the operations were carried out, the transformed digital content of the sheets adequately fits together to make a georeferenced mosaic. The location parameters of the geodetic date used for transformation to modern projection systems are the following: dX = +600 m, dY = +205 m, dZ = +437 m. These figures give exact fit at the Hermannskogel reference point. Because of the not unified geodetic adjustment of the original base point system, using one unified date causes a maximum error of 220 m throughout the whole territory of the Empire and the adjacent area on the maps.
