Review of Problems Associated with Conventional Geodetic Datums

After discussing the parameters needed to define a horizontal geodetic datum, the paper reviews the development of the major geodetic datums. The problem of determining the interrelationships between the various datums is analyzed and current transformation parameters are presented. In view of recent and forthcoming satellite geodetic work, the advantage of separating horizontal and vertical datums is questioned and some suggestions are offered for further definition of geodetic reference systems.