EVALUATION OF THE ACCURACY OF THE NEW PRIMARY PRECISE GEODETIC NETWORK IN KOREA

Accuracy of the Primary Precise Geodetic Network (PPGN) established du ring the period of 1975-1994 in Korea is investigated through an analy sis of residual from free network adjustment. The PPGN, composed of 11 55 points with mean side-length of 11 km, was surveyed by EDM trilater ation to revise old triangulation network established in 1910 s. A-pos teriori standard deviation of unit weight is 3.8 x 10(-6) of the obser ved length. Most of the estimated error ellipses of horizontal coordin ates are nearly circular with a radius <5 cm except those in the margi nal part of the network. Mean error of the adjusted coordinates was +/ -4.5 cm, a value good enough for a geodetic control network of current standard, and as the reference for future crustal deformation studies .