Preliminary Investigation of Belgrade Longitude Variations


D. Djurović




The precise determination of longitude and latitude is of practical importance, especially in geodesy, astronomy and navigation. Historians have noted ,that Spanish king Filip III on ascending the throne 1598., offered an award of 30 000 crowns for the practical resolution of the problem of longitude determination on sea. For the solution of the same problem in 1600. Duch oiifered an award of 100000 florins (Kulikov 1962). The identilfication of real longitude and latitude variations presents a hard, but very important astronomical, geophysical and geodetical task. This task is important nowadays because the increased precision and accuracy of astronomical and geodetical measurements (estimated to a few centimeters) provides the possibility of obtaining accurate perturbations of the orbital elements of artifical satellites, of identifying the local crust deformations and local anomalies in vertical deflection, etc., and of searching for its geophysical causes. The fact that coordinates defining the position of the terrestrial station in space and on the globe vary in time imposes the need of their systematical determination.