An analytic method for the determination of distant terrain corrections

Geophysics ◽  
1982 ◽  
Vol 47 (10) ◽  
pp. 1453-1455 ◽  
Author(s):  
Z. F. Danés
Keyword(s):  
Gravity Field ◽  
Analytical Methods ◽  
Gravity Data ◽  
Analytic Method ◽  
Topographic Map ◽  
Terrain Corrections

Terrain corrections of gravity data are by far the most awkward and time‐consuming reductions needed in exploration geophysics. The terrain must be subdivided into small prisms; the average elevation of each prism must be found on a topographic map; the gravity field of each prism must be determined by analytical methods; and the contributions of all the prisms must be added up.

Study of the accuracy of monthly time-variable satellites gravity field estimates

2021 ◽  
Author(s):  
Hugo Lecomte ◽  
Severine Rosat ◽  
Mioara Mandea
Keyword(s):  
Gravity Field ◽  
Large Scale ◽  
Gravity Data ◽  
European Space Agency ◽  
Field Measurements ◽  
Time Variable ◽  
Research Centre ◽  
Data Products ◽  
Level 2

<p>The GRACE and GRACE Follow-On (GRACE-FO) missions have been providing monthly time-variable gravity field estimates since 2002 with a one-year gap between 2017 and 2018. The Level 2 data products are available through several processing centers with independent computation strategies. The Center of Space Research (CSR), the German Research Centre for Geosciences (GFZ) and the Jet Propulsion Laboratory (JPL) as part of the GRACE/GRACE-FO Science Data System (SDS) process gravity data with RL06 standards. The French National Centre for Space Studies (CNES) and the Graz University of Technology delivered GRACE gravity fields models respectively named <em>CNES/GRGS RL05</em> and <em>ITSG-GRACE2018</em>. Besides GRACE data, the European Space Agency (ESA) delivers Level 2 data products for the Swarm mission. Swarm data enables the evaluation of gap-filling methods between the GRACE and GRACE-FO missions. These datasets are very valuable inputs in studying the Earth's deep interior and could open new windows into the study of core-mantle boundary processes and core dynamics.</p><p> </p><p>Earth's core dynamical processes inferred from geomagnetic field measurements are characterized by large-scale patterns. Studying them via gravity field observations involves the use of spherical harmonic coefficients up to degree and order 10. Particular attention needs to be dedicated to Stokes coefficients that are affected by problematic reconstruction effects such as C<sub>2,0</sub> or C<sub>3,0</sub>. The comparison of time-series from various processing centers with Satellite-Laser Ranging (SLR) gravity products and hydrological loading models provides information on the consistency between different solutions and the accuracy of space gravity field measurements. The correction of hydrological and glacial isostatic adjustment (GIA) effects is an additional source of error in the determination of the gravity field. For example, the actual uncertainty of the GIA model over North America might lead to an error of 10% for some Stokes coefficients. Mismodelling in the seasonal loading could also affect the retrieved Stokes coefficients.</p><p> </p><p>This study firstly provides a comparison of existing gravity field solutions and their accuracy. Secondly, a detailed analysis of different error sources provides us with better estimates of the current limits in the determination of elusive signals coming from the deep Earth's interior. It also offers the possibility to better describe the external sources and then to minimize their contribution to the signal we are interested in.</p>

GRAVITY SURVEYS IN HEAVY SAND DUNES

Geophysics ◽  
1961 ◽  
Vol 26 (4) ◽  
pp. 490-498 ◽  
Author(s):  
G. C. Colley
Keyword(s):  
Gravity Data ◽  
Sand Dunes ◽  
Aerial Photographs ◽  
Dune Sand ◽  
Motor Transport ◽  
Advantages And Disadvantages ◽  
Terrain Corrections

The paper discusses the problems involved in desert surveys under the headings of “Access” and “Correction of Gravity Data.” The types of sand formation are described. In planning a survey the importance of reconnaissance, aerial photographs, and the provision of suitable equipment are stressed. The advantages and disadvantages of motor transport, light aircraft, helicopters, and the operational procedures used with each are discussed. Terrain corrections are necessary on most stations and suggestions are given for their determination. The different densities of the dune sand and the “floor” introduce a problem in the determination of the Bouguer Correction. A method is given whereby close estimates of the sand thickness can be found by contouring on the “floor” or on minimum elevations. The resulting Bouguer values after computation are as regular as those found in areas of small elevational changes.

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

Analytical Methods for Determination of Balofloxacin in Tablets

2012 ◽  
Vol 2 (8) ◽  
pp. 66-68
Author(s):  
Shreya Nayak ◽  
◽  
Sanjay Pai P.N. Sanjay Pai P.N.
Keyword(s):  
Analytical Methods

The relationship between musty-odor-causing organisms and water quality in Lake Biwa

1995 ◽  
Vol 31 (11) ◽  
pp. 153-158 ◽  
Author(s):  
M. Kajino ◽  
K. Sakamoto
Keyword(s):  
Water Quality ◽  
Data Analysis ◽  
Green Algae ◽  
Analytical Methods ◽  
Lake Biwa ◽  
Blue Green Algae ◽  
Odor Compounds ◽  
Musty Odor ◽  
The Relationship

Musty odor has occurred annually in Lake Biwa since 1969. Osaka municipal waterworks, which is located downstream of Lake Biwa, has made many efforts to treat musty-odor compounds produced in Lake Biwa from spring through autumn. With the development of analytical methods for the determination of musty-odor compounds, we have been able to confirm that planktonic blue-green algae are the major causes of the musty-odor occurrences. The relationship between the growth of blue-green algae and the water quality was not so apparent. However, through our data analysis focusing on the relationship between musty-odor occurrences due to Phormidium tenue or Oscillatoria tenuis and some nutrients in Lake Biwa, we found that the concentration of nitrate in water may be an important parameter for the estimation of growth of the algae and the musty-odor behavior.

A Review of Analytical Methods for the Determination of Tibolone: Pharmacokinetics and Pharmaceutical Formulations Analysis and Application in Doping Control

2020 ◽  
Vol 17 (1) ◽  
pp. 31-39
Author(s):  
Marilene Lopes Ângelo ◽  
Fernanda de Lima Moreira ◽  
Ana Laura Araújo Santos ◽  
Hérida Regina Nunes Salgado ◽  
Magali Benjamim de Araújo
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Analytical Methods ◽  
Estrogenic Activity ◽  
Biological Fluids ◽  
Pharmaceutical Formulations ◽  
Doping Control ◽  
Specific Effects ◽  
In Doping

Background:: Tibolone is a synthetic steroid commercialized by Organon under the brand name Livial (Org OD14), which is used in hormone therapy for menopause management and treatment of postmenopausal osteoporosis. Tibolone is defined as a selective tissue estrogenic activity regulator (STEAR) demonstrating tissue-specific effects on several organs such as brain, breast, urogenital tract, endometrium, bone and cardiovascular system. Aims:: This work aims to (1) present an overview of important published literature on existing methods for the analysis of tibolone and/or its metabolites in pharmaceutical formulations and biological fluids and (2) to conduct a critical comparison of the analytical methods used in doping control, pharmacokinetics and pharmaceutical formulations analysis of tibolone and its metabolites. Results and conclusions: : The major analytical method described for the analysis of tibolone in pharmaceutical formulations is High Pressure Liquid Chromatography (HPLC) coupled with ultraviolet (UV) detection, while Liquid Chromatography (LC) or Gas Chromatography (GC) used in combination with Mass Spectrometry (MS) or tandem mass spectrometry (MS/MS) is employed for the analysis of tibolone and/or its metabolites in biological fluids.

Electroanalysis of Tricyclic Psychotropic Drugs using Modified Electrodes

2019 ◽  
Vol 15 (4) ◽  
pp. 423-442 ◽  
Author(s):  
Mona Habibi-Kool-Gheshlaghi ◽  
Farnoush Faridbod ◽  
Mahya Karami Mosammam ◽  
Mohammad Reza Ganjali
Keyword(s):  
Psychotropic Drugs ◽  
Analytical Methods ◽  
Electrochemical Techniques ◽  
Modified Electrodes ◽  
Electroanalytical Methods ◽  
Drug Assays ◽  
Medical Importance ◽  
Tricyclic Rings ◽  
Easy Operation

Background: Tricyclic psychotropic drugs are defined as a tricyclic rings of the dibenzazepine group with the presence of sulfur and nitrogen atoms. They have been prescribed for antidepressive therapy over the years. Due to their medical importance, many analytical methods have been developed for their monitoring. However, benefits of electrochemical techniques such as costeffectiveness, fast, easy operation and non-destructiveness make them appropriate analytical methods for drug assays. Electrochemical determinations of pharmaceuticals require suitable working electrodes. During years, many electrodes are modified by a variety of modifiers and several sensors were developed based on them. In this regard, nanomaterials, due to their remarkable properties, are one of the most important choices. Objective: Here, the application of electroanalytical methods in the determination of electroactive tricyclic psychotropic drugs will be reviewed and the nanomaterials which are used for improvements of the working electrodes will be considered.

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