Comments to X. Li and Y. M. Wang (2011) Comparisons of geoid models over Alaska computed with different Stokes' kernel modifications, JGS 1(2): 136−142 Communication
نویسنده
چکیده
Li andWang recently comparedgeoiddeterminationbyvariousgravimetricmethods formodifyingStokes' formula vs. usingGPS/levelling geoid heights as a reference model. Possible large systematic errors in the differences of gravimetric and GPS/levelling geoid models deteriorate the results and conclusions. Moreover, spectral combination, the only stochastic method in the study, was applied in an unrealistic way.
منابع مشابه
Comparisons of geoid models over Alaska computed with different Stokes' kernel modifications
Various Stokes kernel modification methods have been developed over the years. The goal of this paper is to test the most commonly used Stokes kernel modifications numerically by using Alaska as a test area and EGM08 as a reference model. The tests show that some methods are more sensitive than others to the integration cap sizes. For instance, using the methods of Vaníček and Kleusberg or Feat...
متن کاملReply to Comments to X. Li and Y. M. Wang (2011) Comparisons of geoid models over Alaska computed with different Stokes' kernel
The authors thank professor Sjöberg for having interest in our paper. The main goal of the paper is to test kernel modification methods used in geoid computations. Our tests found that Vanicek/Kleusberg's and Featherstone's methods fit the GPS/leveling data the best in the relative sense at various cap sizes. At the same time, we also pointed out that their methods are unstable and the mean val...
متن کاملInvestigation of the Efficiency of Multi-purpose Gravity Network of NCC to Precise Geoid Determination, Case Study: Northwest Area of Iran
The national height system of Iran, orthomertic height, is referred to geoid as the vertical datum. Consequently, the geoid has many important applications in engineering. The slow, laborious and expensive orthomertic heights can be obtained in sufficient accuracy level from geodetic height (derived by GNSS observations) and a precise geoidal height. Over the past two decades, the gravity divis...
متن کاملThe evil role of spike in the coronaviruses: structure, function and evolution
1. Lu R, Zhao X, Li J, et al (2020) Genomic characterisation and epidemiology of 2019 novel coronavirus: implications for virus origins and receptor binding. Lancet 395:565–574 2. Zhou P, Tachedjian M, Wynne JW, et al (2016) Contraction of the type i IFN locus and unusual constitutive expression of IFN-α in bats. Proc Natl Acad Sci U S A 113:2696–2701 . doi: 10.1073/pnas.1518240113 3. Wu A, P...
متن کاملComparison of remove-compute-restore and least squares modification of Stokes' formula techniques to quasi-geoid determination over the Auvergne test area
The remove-compute-restore (RCR) technique for regional geoid determination implies that both topography and low-degree global geopotential model signals are removed before computation and restored after Stokes' integration or Least Squares Collocation (LSC) solution. The Least Squares Modification of Stokes' Formula (LSMS) technique not requiring gravity reductions is implemented here with a R...
متن کامل