in many countries, leveling networks are established for height determination which is one of the most important topics in geodesy. in these networks, the sum of the leveled height differences between a and b will not be equal to the difference in the orthometric heights ha and hb. the reason is that the leveling increment ?n, as we henceforth denote it, is different from the corresponding incr...

To select the best geo-potential model for the determination of Hong Kong and Shenzhen local geoids, three models EGM96, WDM94 and GPM98CR were tested in the region using GPS/leveling data and gravity measurements. The data include GPS/leveling observations at 43 stations, 640 gravity measurements covering the whole territory of Hong Kong, and 62 high precision GPS/leveling observations and 487...

the simple method for height determination is spirit leveling. the leveled height differences are path-dependent. ergo height from spirit leveling is not unique. the problem can be solved by converting the path-dependent leveled height differences into unique path-independent height differences (vanicek and krakiwsky, 1986). the difference between the potentials of two close equipotential surfa...

Vertical geodesy is undergoing a revolution because of two factors. First, new precise three-dimensional position measurement techniques used over very long distances and based on extraterrestrial reference systems provide a new class and precision of geometric data previously unavailable for geophysical investigations. Second, physical models in tectonic theory for large earthquakes predict cr...

the earth’s gravity field dedicated missions provide homogeneous and uniformly accurate information on the long wavelengths of the earth’s gravity field. many different global geopotential models have introduced by earth and space research centers during the last years. the geopotential models derived from the grace satellite measurements are compared with the other models at different frequenc...

one of the most important problems in geodesy is the unification of height datum. generally in geodesy; there are two types of height systems, the geometrical height based on ellipsoid and the physical height based on gravity-defined surface (zhang et al, 2009).local height datum is determined according to mean sea level (msl). in regarding to mismatch of mean sea level and geoid, on the one ha...

We adopt Poisson wavelets for regional gravity field recovery using data acquired from various observational techniques; the method combines data of different spatial resolutions and coverage, and various spectral contents and noise levels. For managing the ill-conditioned system, the performances of the zeroand first-order Tikhonov regularization approaches are investigated. Moreover, a direct...

nowadays, combination of gps heights with orthometric heights, derived from precise leveling, is broadly used to obtain point-wise solutions of the geoid, which is called “gps/leveling geoid”. the “gps/leveling geoid” is commonly used to constrain the gravimetric geoid solutions in a least squares surface fitting process. in this paper, unlike the usual application, the “gps/leveling geoid” is ...

In project scheduling, many problems can arise when resource fluctuations are beyond acceptable limits. To overcome this, mathematical techniques have been developed for leveling resources. However, these produce a hard and inflexible approach in scheduling projects. The authors propose a simple resource leveling approach that can be used in scheduling projects with multi-mode execution activit...