Determining the height of Mount Everest using the shallow layer method

2021 ◽  
Author(s):  
Youchao Xie ◽  
Wenbin Shen ◽  
Jiancheng Han ◽  
Xiaole Deng
Keyword(s):  
Gravity Field ◽  
Field Model ◽  
Space Station ◽  
Geoid Undulation ◽  
Mount Everest ◽  
Gravity Field Model ◽  
Terrain Model ◽  
Earth Gravity ◽  
Layer Method ◽  
Shallow Layer

<p>We proposed an alternative method to determine the height of Mount Everest (HME) based on the shallow layer method (SLM), which was put forward by Shen (2006). We use the precise external global Earth gravity field model (i.e., EGM2008 and EIGEN-6C4 models) as input information, and the digital topographic model (i.e., DTM2006.0) and crust models (i.e., CRUST2.0 and CRUST1.0 models) to construct the shallow layer model. There are four combined strategies：(1) EGM2008 and CRUST1.0 models, (2) EGM2008 and CRUST2.0 models, (3) EIGEN-6C4 and CRUST1.0 models, and (4) EIGEN-6C4 and CRUST2.0 models, respectively. We calculate the HME by two approaches: first approach, the HME is directly calculated by combining the geoid undulation (N) and geodetic height (h); second approach, we calculate the HME by the segment summation approach (SSA) using the gravity field inside the shallow layer determined by the SLM. Numerical results show that for four combined strategies, the differences between our results and the authoritatively released value 8848.86 m by the Chinese and Nepalese governments on December 8, 2020 are 0.448 m, -0.009 m, -0.295 m, and -0.741 m using first approach and 0.539 m, 0.083 m, -0.214 m, and -0.647 m using second approach. The combined calculation of the HME by the terrain model and gravity field model is more accurate than that by the gravity field model alone. This study is supported by the National Natural Science Foundations of China (NSFC) under Grants 42030105, 41721003, 41804012, 41631072, 41874023, Space Station Project (2020)228.</p>

Development of a global geoid model 2020 (GGM2020)

2020 ◽  
Author(s):  
WenBin Shen ◽  
Youchao Xie ◽  
Jiancheng Han ◽  
Jiancheng Li
Keyword(s):  
Gravity Field ◽  
Density Model ◽  
Layer Model ◽  
Geoid Model ◽  
Gravity Field Model ◽  
Layer Method ◽  
Shallow Layer ◽  
Inner Surface ◽  
Gps Leveling ◽  
Better Than

<p>We present an updated 5′ ×5′ global geoid model 2020 (GGM2020), which is determined based on the shallow layer method (or simply Shen method). We choose an inner surface S below the EGM2008 global geoid by 15 m, and the layer bounded by the inner surface S and the Earths geographical surface E is referred to as the shallow layer. We formulate the 3D shallow mass layer model using the refined 5′ ×5′ crust density model, CRUST1.0-5min, which is an improved 5′ ×5′ density model of the CRUST1.0 with taking into account the corrections of the areas covered by ice sheets and the land-ocean crossing regions. Based on the shallow mass layer model and the gravity field EGM2008 that is defined in the region outside the Earth’s geographical surface E, we determine the gravity field model EGM2008S that is defined in the whole region outside the inner surface S. Based on the gravity field EGM2008S and the geoid equation W(P) =W0, where W0 is the geopotential constant on the geoid and P is the point on the geoid G, we established a 5′ ×5′ global geoid model GGM2020. Comparisons show that in average the GGM2020 fits the globally available GPS/leveling points better than the EGM2008 global geoid. This study is supported by NSFCs (grant Nos. 41721003, 41631072, 41874023, 41804012, 41429401, 41574007).</p>

GGM02 – An improved Earth gravity field model from GRACE

2005 ◽  
Vol 79 (8) ◽  
pp. 467-478 ◽  
Author(s):  
B. Tapley ◽  
J. Ries ◽  
S. Bettadpur ◽  
D. Chambers ◽  
M. Cheng ◽  
...  
Keyword(s):  
Gravity Field ◽  
Field Model ◽  
Gravity Field Model ◽  
Earth Gravity Field ◽  
Earth Gravity ◽  
Earth Gravity Field Model

Determination of Earth Gravity Field Model WHU-GM-05 Using Grace Gravity Data

2008 ◽  
Vol 51 (5) ◽  
pp. 967-975 ◽  
Author(s):  
Zheng-Tao WANG ◽  
Jian-Cheng LI ◽  
Wei-Ping JIANG ◽  
Ding-Bo CHAO
Keyword(s):  
Gravity Field ◽  
Field Model ◽  
Gravity Data ◽  
Gravity Field Model ◽  
Earth Gravity Field ◽  
Earth Gravity ◽  
Earth Gravity Field Model

The CHAMP-only earth gravity field model EIGEN-2

2003 ◽  
Vol 31 (8) ◽  
pp. 1883-1888 ◽  
Author(s):  
Ch Reigber ◽  
P Schwintzer ◽  
K.-H Neumayer ◽  
F Barthelmes ◽  
R König ◽  
...  
Keyword(s):  
Gravity Field ◽  
Field Model ◽  
Gravity Field Model ◽  
Earth Gravity Field ◽  
Earth Gravity ◽  
Earth Gravity Field Model

An Earth gravity field model complete to degree and order 150 from GRACE: EIGEN-GRACE02S

2005 ◽  
Vol 39 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Christoph Reigber ◽  
Roland Schmidt ◽  
Frank Flechtner ◽  
Rolf König ◽  
Ulrich Meyer ◽  
...  
Keyword(s):  
Gravity Field ◽  
Field Model ◽  
Gravity Field Model ◽  
Earth Gravity Field ◽  
Earth Gravity ◽  
Earth Gravity Field Model

Precise LEO satellite orbit determination and Earth gravity field modeling with carrier-range method

2020 ◽  
Author(s):  
Geng Gao ◽  
Xiancai Zou ◽  
Shoujian Zhang ◽  
Bingshi Liu
Keyword(s):  
Gravity Field ◽  
Field Model ◽  
Satellite Orbit ◽  
Gravity Field Model ◽  
Earth Gravity Field ◽  
Earth Gravity ◽  
Field Modeling ◽  
Earth Gravity Model ◽  
Gravity Field Modeling ◽  
Leo Satellite

<p>Precise LEO satellite orbit determination(OD) and Earth gravity field modeling are researched in this study.</p><p>Firstly, on the basis of Precise Point Positioning Ambiguity Resolution(PPPAR), a kinematic LEO satellite OD algorithm based on the epoch-difference and post-facto iteration is introduced, which plays a vital rule in the detection of the phase cycle slip to achieve the best orbit accuracy. The experiments of GRACE satellite OD with zero-difference IF combination observations spanning one year of 2010 show that, compared to the JPL reference orbits, the daily average 3D RMS is generally below 5.0cm for the float solution, while that is below 4.0cm for the fixed solution.</p><p>Secondly, to solve the problem that specific a-priori information like earth gravity field model must be involved in LEO’ reduced dynamic OD, the simultaneous solution method, which is specially on the relation with the kinematic OD and reduced dynamic OD, is used and the carrier-range, which can be recovered from phase observations once the kinematic OD process using Integer Ambiguity Resolution (IAR) technology is carried out, is naturally applied to this method. With the experiments based on the data over a period of the year of 2010, comes some evacuations, including the external checks on the accuracy of the orbits and the analysis on the earth gravity model. The numerical results show that, compared to the JPL reference orbits, the 3D RMS is below 3.0cm and the RMS is below 2.0cm for each component. As for the accuracy of gravity field model, compared to some contemporary significant earth gravity model, the model of the single month solution behaves very well below the 60 degree of the gravity field’s coefficients, while over the 60 degree, only the UTCSR model quite corresponds to the model computed by this method. Therefore, due to the promotion of the orbital accuracy and gravity field model, we suggest that the recovered carrier-range should be implemented in the simultaneous method for the better product solution of the LEO’s missions.</p>

Sign in / Sign up

Export Citation Format

Share Document