Application of global geopotential models to high-precesion levelling processing

2017 ◽  
Vol 926 (8) ◽  
pp. 2-9
Author(s):  
V.V. Popadyev ◽  
D.A. Kuliev
Keyword(s):  
Field Model ◽  
Direct Evaluation ◽  
Gravity Field Model ◽  
Bouguer Anomalies ◽  
Free Air ◽  
Geopotential Models ◽  
Integral Characteristics ◽  
Indirect Evaluation ◽  
Gravity Map ◽  
High Degree

The article studies the properties of the high-degree gravity field model EGM-2008 in the calculation of integral characteristics at large distances several times greater than the spatial resolution of the model. As an example of an indirect evaluation of a high-degree model, a gravimetric correction was computed into the sum of the measured elevations along the line of the high-precision I class leveling of the Krasnovodsk – Chardzhou line located in Turkmenistan. Using the calculator ICGEM, the Bouguer anomalies were calculated at each point of the line, then the attraction of the Bouguer layer (used heights are from catalog) excluded for the transition to free-air anomalies. In parallel, for a direct evaluation of the model, a regular grid of Bouguer anomalies with a step of 2 angular minutes within line area was also obtained, which were then compared with the anomalies from the gravity map J-40 of scale 1

scholarly journals Analisis Continuous Wavelet Transform (CWT) Anomali Residual Medan Gravitasi Di Situs Geologi Karangsambung Kebumen Jawa Tengah

2019 ◽  
Vol 2 (2) ◽  
pp. 61
Author(s):  
Wahyu Hidayat ◽  
Wrego Seno Giamboro
Keyword(s):  
Wavelet Transform ◽  
Continuous Wavelet Transform ◽  
Continuous Wavelet ◽  
Gravity Method ◽  
Rock Density ◽  
Bouguer Anomalies ◽  
Central Java ◽  
Free Air ◽  
Data Survey ◽  
High Degree

Gravity method is a passive geophysical method that provides information on the distribution of rock density below the surface. The gravity method has a weakness at the level of ambiguity in determining the depth of the anomaly. This study aims to determine the depth of the anomaly using Continuous Wavelet Transform (CWT) analysis to overcome the value of ambiguity, so that the results obtained have a high degree of accuracy. The research method is data survey / acquisition and data analysis. This research was conducted in Karangsambung Kebumen, Central Java with the acquisition of gravitational data as many as 56 measurement points. The results of data acquisition then analyzed included reading to mGal, tool height correction, drift, tides, latitude, free air correction, Bouguer correction, and field correction. The results of this correction obtained Complete Bouguer Anomalies (ABL) values which were then reduced to flat fields and regional-residual anomaly filters. The next step is CWT analysis by making incisions on residual anomaly maps. The results showed that the source of the anomaly was between ± 39.2 - 122.9 meters.

Gravity map of Brazil: 1. Representation of free-air and Bouguer Anomalies

1993 ◽  
Vol 98 (B2) ◽  
pp. 2187-2197 ◽  
Author(s):  
Nelsi Côgo de Sá ◽  
Naomi Ussami ◽  
Eder Cassola Molina
Keyword(s):  
Bouguer Anomalies ◽  
Free Air ◽  
Gravity Map

scholarly journals Assessment of high-degree reference models and Recent Goce/Grace Global Geopotential Models over Sudan based on the GPS/Leveling data

2021 ◽  
Vol 936 (1) ◽  
pp. 012035
Author(s):  
Anas Sharafeldin Mohamed Osman ◽  
Ira Mutiara Anjasmara ◽  
Abdelrahim Ruby ◽  
Zahroh Arsy Udama
Keyword(s):  
Gravity Field ◽  
Gravity Data ◽  
Airborne Gravity ◽  
Accuracy Evaluation ◽  
Geoid Model ◽  
Gravity Field Model ◽  
Reference Models ◽  
Geopotential Models ◽  
Gps Leveling ◽  
High Degree

Abstract Nowadays, Global Geopotential Models (GGMs) can be used as a reference to develop more detailed regional/local geoids, or they can be used to provide geoid heights on their own. Since 2000, several GGMs have been released, and they are mainly derived from satellite gravity measurements, satellite-only models, terrestrial gravimetry, altimeter-derived gravity data in marine areas, and airborne gravity data. With a precise geoid model, ellipsoidal heights obtained from GPS can be converted to orthometric heights, which is reasonably quite needed in Geodesy, Civil Engineering, etc. These heights reflect changes in topography as well as local variations in gravity. This paper evaluates some of the latest releases of high degree reference models and the satellite-only global gravity field model over Sudan using 19 GPS/Leveling stations. We have been selected 6 GGMs based on Gravity field Goce and Grace, and they released in 2020, 2019, 2014, 2008, and 1996 as shown in the International Centre for Global Earth Models website (ICGEM). The accuracy evaluation of the GGM models have been discussed, the accurate GGMs over Sudan are XGM2019e_2159 and GOCO05s, which have indicated -0.019 and 0.046 meters, respectively. The evaluation results produce valuable information to academia and geoid modeling research topics in Sudan, which shows the precise model from the selected GGMs in Sudan by using the available GPS/Leveling data.

Current uses of intracranial vessel wall imaging for clinical practice: a high-resolution MR technique recently available

2020 ◽  
Vol 78 (10) ◽  
pp. 642-650
Author(s):  
Felipe Torres PACHECO ◽  
Luiz Celso Hygino da CRUZ JUNIOR ◽  
Igor Gomes PADILHA ◽  
Renato Hoffmann NUNES ◽  
Antônio Carlos Martins MAIA JUNIOR ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Vessel Wall ◽  
Vascular Diseases ◽  
Vascular Wall ◽  
Vessel Wall Imaging ◽  
Clinical Settings ◽  
Direct Evaluation ◽  
Intracranial Vessel ◽  
Indirect Evaluation ◽  
Wall Imaging

ABSTRACT Intracranial vessel wall imaging plays an increasing role in diagnosing intracranial vascular diseases. With the growing demand and subsequent increased use of this technique in clinical practice, radiologists and neurologists should be aware of the choices in imaging parameters and how they affect image quality, clinical indications, methods of assessment, and limitations in the interpretation of these images. Due to the improvement of the MRI techniques, the possibility of accurate and direct evaluation of the abnormalities in the arterial vascular wall (vessel wall imaging) has evolved, adding substantial data to diagnosis when compared to the indirect evaluation based on conventional flow analyses. Herein, the authors proposed a comprehensive approach of this technique reinforcing appropriated clinical settings to better use intracranial vessel wall imaging.

Documentation et gestion du patrimoine archéologique de la chaîne montagneuse tuniso-libyenne via l'utilisation des nouvelles technologies : résultats préliminaires

2021 ◽  
pp. 1-16
Author(s):  
Héla Mekki
Keyword(s):  
New Technologies ◽  
Management Plan ◽  
Archaeological Sites ◽  
Mountain Range ◽  
Direct Evaluation ◽  
Nouvelles Technologies ◽  
Data Assessment ◽  
Conservation Plan ◽  
Indirect Evaluation ◽  
Management And Conservation

Abstract The mountain range formed by Jebels Matmata, Demmer and Nefoussa which links the two countries, Tunisia and Libya, is strewn with archaeological remains that are little known today, due in part to the rugged terrain which makes it difficult to see them. This issue has been helped by the use of new technologies, in this case remote sensing and QGIS software. Archaeological evidence has been uncovered and more than 3,900 sites and monuments have been detected on the sides of these mountains. In addition to the inventory of unknown archaeological sites, the main aim of the work was to draw up a management and conservation plan to provide, with an order of priority, a strategy for the safeguard and conservation of the mountain heritage. This management plan was only possible through a correlation of three data: assessment of values, identification of threats, and study of the state of conservation. These components were studied using an indirect evaluation based on satellite imagery and direct evaluation through field visits.

A 1.5km-resolution gravity field model of the Moon

2012 ◽  
Vol 329-330 ◽  
pp. 22-30 ◽  
Author(s):  
C. Hirt ◽  
W.E. Featherstone
Keyword(s):  
Gravity Field ◽  
Field Model ◽  
The Moon ◽  
Gravity Field Model

scholarly journals EVALUATION AND TAILORING OF GLOBAL GEOPOTENTIAL MODELS IN THE DETERMINATION OF GRAVITY FIELD IN SERBIA

2020 ◽  
Vol 14 (1) ◽  
Author(s):  
Oleg Odalović ◽  
Danilo Joksimović ◽  
Dušan Petković ◽  
Marko Stanković ◽  
Sanja Grekulović
Keyword(s):  
Global Navigation Satellite Systems ◽  
Satellite Systems ◽  
Average Value ◽  
Free Air ◽  
Geopotential Models ◽  
Normal Heights ◽  
Discrete Values ◽  
Global Navigation Satellite

Within this paper, we evaluated the quality of three Global Geopotential Models entitled: EGM96,EGM2008, and GOCO05c. The models were evaluated by using 1001 terrestrial discrete values ofheight anomalies determined by Global Navigation Satellite Systems and normal heights, which weconsidered to be true values within this research. In addition to the quality evaluation, we tailoredthe models by using more than 80000 free air anomalies. The results obtained from the evaluationand tailoring indicate that by using the GOCO05c it is possible to determine a set of anomaly heightsacross Serbia, which are in agreement with terrestrial values with an average value of -7 cm, thestandard deviation of ±9 cm and with the range of 44 cm.

scholarly journals The combined global gravity field model XGM2019e

2020 ◽  
Vol 94 (7) ◽  
Author(s):  
P. Zingerle ◽  
R. Pail ◽  
T. Gruber ◽  
X. Oikonomidou
Keyword(s):  
Gravity Field ◽  
Field Model ◽  
Gravity Field Model ◽  
Global Gravity ◽  
Global Gravity Field Model
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