Geodesy is the science of measuring and mapping the geometry, orientation and gravity field of the Earth including the associated variations with time. Geodesy has also provided the foundation for high accuracy surveying and mapping. Modern Geodesy involves a range of space and terrestrial technologies that contribute to our knowledge of the solid earth, atmosphere and oceans. These technologie...

The International GPS Service (IGS) has provided GPS orbit products to the scientific community with increased precision and timeliness. Many users interested in geodetic positioning have adopted the IGS precise orbits to achieve centimeter level accuracy and ensure long-term reference frame stability. Currently, a differential positioning approach that requires the combination of observations ...

A “dynamic” geodetic datum is a datum that consists of coordinates and velocities of control points, which can provide users with the realistic positions of sites within the network that reflects the result of local or regional motion induced by a number of causes. A new ITRF-linked scheme is proposed and discussed in order to process available geodetic data in real-time to establish a dynamic ...

the basic National horizontal and vertical networks of geodetic control and provides governmentwide leadership in the improvement of geodetic surveying methods and instrumentation, coordinates operations to assure network development, and provides specifications and criteria for survey operations by Federal, State, and other agencies. NGS engages in research and development for the improvement ...

The Problem: Since the advent of satellite positioning users have been faced with the need to transform coordinates delivered by the satellite based systems to those based on the national geodetic system of the country or area concerned. Transformations between Co-ordinate Reference Systems based on different geodetic datums (sometimes colloquially referred to as “datum shifts”) used within oil...

Much local government has been utilizing a large-scale digital map using Geographic Information System (GIS). However, the maintenance and renewal of a map database need much labor and time. Moreover, the updating method of a map has not been established yet and there have been almost no successful examples. The purpose of the study is to establish a method of updating the large-scale map for l...

The processing of the Global Positioning System (GPS) observables is regularly performed using some “a priori” standard meteorological values. These can be very unrealistic if only few observations are available since the actual atmospheric conditions over the geodetic network are neglected. This seems to be the case of randomly moving GPS receivers far from continuously observing reference sta...

Introduction: Landers on the surface of Mars constitute unique landmarks for geodetic control point networks. Typically, their positions with respect to prominent surrounding surface features and their Mars-fixed coordinates, derived from radio tracking, are well established. Unfortunately, Viking 2 landed in a vast desert, which lacked prominent surface markings in its neighborhood. Hence, tho...

An edge geodetic set of a connected graph G of order p ≥ 2 is a set S ⊆ V (G) such that every edge of G is contained in a geodesic joining some pair of vertices in S. The edge geodetic number g1(G) of G is the minimum cardinality of its edge geodetic sets and any edge geodetic set of cardinality g1(G) is a minimum edge geodetic set of G or an edge geodetic basis of G. An edge geodetic set S in ...