Toward high-quality magnetic data survey using UAV: development of a magnetic-isolated vision-based positioning system

GPS Solutions ◽  
2021 ◽  
Vol 25 (1) ◽  
Author(s):  
Xiao Hu ◽  
Daniel Olesen ◽  
Per Knudsen
Keyword(s):  
Magnetic Data ◽  
Positioning System ◽  
High Quality ◽  
Data Survey

Limitations on digital filtering of the DNAG magnetic data set for the conterminous U.S.

Geophysics ◽  
1993 ◽  
Vol 58 (9) ◽  
pp. 1281-1296 ◽  
Author(s):  
V. J. S. Grauch
Keyword(s):  
Spatial Frequency ◽  
North American ◽  
Digital Filtering ◽  
Magnetic Data ◽  
Data Sets ◽  
Frequency Content ◽  
Long Distance ◽  
High Quality ◽  
Data Set ◽  
The U.S

The magnetic data set compiled for the Decade of North American Geology (DNAG) project presents an important digital data base that can be used to examine the North American crust. The data represent a patchwork from many individual airborne and marine magnetic surveys. However, the portion of data for the conterminous U.S. has problems that limit the resolution and use of the data. Now that the data are available in digital form, it is important to describe the data limitations more specifically than before. The primary problem is caused by datum shifts between individual survey boundaries. In the western U.S., the DNAG data are generally shifted less than 100 nT. In the eastern U.S., the DNAG data may be shifted by as much as 300 nT and contain regionally shifted areas with wavelengths on the order of 800 to 1400 km. The worst case is the artificial low centered over Kentucky and Tennessee produced by a series of datum shifts. A second significant problem is lack of anomaly resolution that arises primarily from using survey data that is too widely spaced compared to the flight heights above magnetic sources. Unfortunately, these are the only data available for much of the U.S. Another problem is produced by the lack of common observation surface between individual pieces of the U.S. DNAG data. The height disparities introduce variations in spatial frequency content that are unrelated to the magnetization of rocks. The spectral effects of datum shifts and the variation of spatial frequency content due to height disparities were estimated for the DNAG data for the conterminous U.S. As a general guideline for digital filtering, the most reliable features in the U.S. DNAG data have wavelengths roughly between 170 and 500 km, or anomaly half‐widths between 85 and 250 km. High‐quality, large‐region magnetic data sets have become increasingly important to meet exploration and scientific objectives. The acquisition of a new national magnetic data set with higher quality at a greater range of wavelengths is clearly in order. The best approach is to refly much of the U.S. with common specifications and reduction procedures. At the very least, magnetic data sets should be remerged digitally using available or newly flown long‐distance flight‐line data to adjust survey levels. In any case, national coordination is required to produce a consistent, high‐quality national magnetic map.

Reduction to the pole at low latitudes by Wiener filtering

Geophysics ◽  
1989 ◽  
Vol 54 (12) ◽  
pp. 1607-1613 ◽  
Author(s):  
R. O. Hansen ◽  
R. S. Pawlowski
Keyword(s):  
Frequency Domain ◽  
Synthetic Data ◽  
Wiener Filtering ◽  
Magnetic Data ◽  
Noise Power ◽  
Low Latitude ◽  
High Quality ◽  
Computational Load ◽  
Low Latitudes ◽  
Reduction To The Pole

Using simple estimates of the signal and noise power from gridded magnetic data, we design regulated frequency‐domain operators for reduction to the pole at low magnetic latitudes. These operators suppress the artifacts along the direction of the magnetic declination associated with the conventional reduction‐to‐the‐pole procedure, with negligible increase in computational load. The new procedure is applied to produce high‐quality reductions to the pole for noisy low‐latitude synthetic data and for magnetic data from the Dixon Seamount.

scholarly journals A Survey on Healthcare Systems using Internet of Things

2021 ◽  
Vol 37 ◽  
pp. 01015
Author(s):  
Chitra Ramesh ◽  
Jayalakshmi Sekar
Keyword(s):  
Internet Of Things ◽  
Analytical Approach ◽  
Healthcare Systems ◽  
The Internet ◽  
High Quality ◽  
Interesting Issue ◽  
Reference Table ◽  
The Public ◽  
Data Survey ◽  
The Internet Of Things

The Internet of Things allows things to become active users, facilitating interaction with things and the sharing of data between them. The most interesting issue in the science world, the public sector and industry in the IoT is unavoidable. It ensures a seamless relationship between doctors and patients that results in medical treatment with high quality results. This is accomplished by constant surveillance of patients through the use of sensors. The collected data is registered for potential uses and used for analytics. The analytical approach offers the opportunity for disease detection in healthcare results. This paper concerns the Internet of Things in healthcare and explores the different algorithms used in it. The system involved in analytics of healthcare and data sources involved in analytics are further clarified. Finally this paper demonstrates the Internet of Things and Big Data survey of healthcare systems with a reference table.

How Effective Are Eye-Tracking Data in Identifying Problematic Questions?

2019 ◽  
Vol 38 (6) ◽  
pp. 793-802
Author(s):  
Cornelia E. Neuert
Keyword(s):  
Eye Tracking ◽  
Cognitive Effort ◽  
Quality Data ◽  
Promising Technique ◽  
High Quality ◽  
High Quality Data ◽  
Survey Questions ◽  
Data Limitations ◽  
Data Survey ◽  
Practical Implications

To collect high-quality data, survey designers aim to develop questions that each respondent can understand as intended. A critical step to this end is designing questions that minimize the respondents’ burden by reducing the cognitive effort required to comprehend and answer them. One promising technique for identifying problematic survey questions is eye tracking. This article investigates the potential of eye movements and pupil dilations as indicators for evaluating survey questions. Respondents were randomly assigned to either a problematic or an improved version of six experimental questions. By analyzing fixation times, fixation counts, and pupil diameters, it was examined whether these parameters could be used to distinguish between the two versions. Identifying the improved version worked best by comparing fixation times, whereas in most cases, it was not possible to differentiate between versions on the basis of pupil data. Limitations and practical implications of the findings are discussed.

scholarly journals Improved compilationof Antarctic Peninsula magnetic data by new interactive grid suturing and blending methods

1999 ◽  
Vol 42 (2) ◽  
Author(s):  
A. Johnson ◽  
S. Cheeseman ◽  
J. Ferris
Keyword(s):  
Magnetic Data ◽  
Data Sets ◽  
Gridded Data ◽  
Remote Region ◽  
Considerable Effort ◽  
High Quality ◽  
Blending Method ◽  
Bellingshausen Sea ◽  
Antarctic Continent ◽  
The Antarctic

The utility of aeromagnetic and other geoscientific compilations on a range of scales, is well established for a wide variety of geological investigations. Aeromagnetic compilations, currently underway for the Antarctic continent are vital to take full advantage of existing aeromagnetic surveys and for planning new surveys of this relatively unknown continent. Grid compilation is often a time-consuming and subjective task, which requires considerable effort from the geoscientist involved. A new interactive grid compilation tool, GridKnit™, is presented, which enables the operator to rapidly combine gridded data sets with high quality results. The system offers two methods: a conventional blending method and a new suturing method. The blending method distributes the errors between grids over the area of overlap, effectively 'feathering' one grid into the other. The suturing method uses an analysis of the wavelengths of the data mismatches to correct each grid by an amount proportional to that wavelength. Each method has been applied to data sets from the Bellingshausen Sea-Alexander Island area of Antarctica to produce the first coherent magnetic map of this remote region.

scholarly journals Reducing Magnetic Noise of an Unmanned Aerial Vehicle for High-Quality Magnetic Surveys

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Boris Sterligov ◽  
Sergei Cherkasov
Keyword(s):  
Combustion Engine ◽  
Ore Deposits ◽  
Geological Mapping ◽  
Magnetic Data ◽  
Magnetic Survey ◽  
Aeromagnetic Data ◽  
High Quality ◽  
Plain Area ◽  
Aerodynamic Modeling ◽  
Aerial Vehicle

The use of light and ultralight unmanned aerial vehicles (UAVs) for magnetic data acquisition can be efficient for resolving multiple geological and engineering tasks including geological mapping, ore deposits’ prospecting, and pipelines’ monitoring. The accuracy of the aeromagnetic data acquired using UAV depends mainly on deviation noise of electric devices (engine, servos, etc.). The goal of this research is to develop a nonmagnetic unmanned aerial platform (NUAP) for high-quality magnetic surveys. Considering parameters of regional and local magnetic survey, a fixed-wing UAV suits geological tasks better for plain area and copter type for hills and mountains. Analysis of the experimental magnetic anomalies produced by a serial light fixed-wing UAV and subsequent magnetic and aerodynamic modeling demonstrates a capacity of NUAP with internal combustion engine carrying an atomic magnetic sensor mounted on the UAV wings to facilitate a high-quality magnetic survey.

scholarly journals Advances in Optomechatronics: An Automated Tilt-Rotational 3D Scanner for High-Quality Reconstructions

Photonics ◽  
2018 ◽  
Vol 5 (4) ◽  
pp. 42 ◽  
Author(s):  
Silvia Logozzo ◽  
Maria Valigi ◽  
Gabriele Canella
Keyword(s):  
Degrees Of Freedom ◽  
Vision System ◽  
Research Work ◽  
Positioning System ◽  
Performance Tests ◽  
Performance Parameters ◽  
3D Scanner ◽  
High Quality ◽  
3D Vision ◽  
System A

3D vision systems are more and more required in a large variety of applications and mostly for mechanical and medical purposes. This paper presents the study and realization of a prototype of a structured light automated tilt-rotational 3D vision system for high-quality reconstructions of components of various sizes and in cases of freeform and complex surfaces. The main goal of this research work was to develop an instrument with the following main novelties: configurability for different object sizes, high precision and resolution levels and ability to automatically generate the mesh representing the full scanned objects without any intervention of the operator by means of a 2 degrees of freedom automated tilt-rotational mechanical positioning system. A detailed analysis of the instrument and the procedures and results of the performance tests are presented, together with the examination of possible strategies to obtain a better performance, especially by the calibration and the synchronization between the optical and the mechanical systems. As a result, the prototype and the performance parameters resulting from the experimental campaigns, are reported.

Some problems of objective-prism spectra classification

1966 ◽  
Vol 24 ◽  
pp. 51-52
Author(s):  
E. K. Kharadze ◽  
R. A. Bartaya
Keyword(s):  
Short Wave ◽  
High Quality ◽  
Stellar Spectra ◽  
Objective Prism

The unique 70-cm meniscus-type telescope of the Abastumani Astrophysical Observatory supplied with two objective prisms and the seeing conditions characteristic at Mount Kanobili (Abastumani) permit us to obtain stellar spectra of a high quality. No additional design to improve the “climate” immediately around the telescope itself is being applied. The dispersions and photographic magnitude limits are 160 and 660Å/mm, and 12–13, respectively. The short-wave end of spectra reaches 3500–3400Å.

A non-cyanide method of electropolishing silver

1978 ◽  
Vol 36 (1) ◽  
pp. 146-147
Author(s):  
R. L. Lyles ◽  
S. J. Rothman ◽  
W. Jäger
Keyword(s):  
Electron Microscopy ◽  
Sulphuric Acid ◽  
Methyl Alcohol ◽  
Health Hazards ◽  
Silver Alloy ◽  
High Quality ◽  
Silver Alloys ◽  
Free Sample ◽  
Specimen Quality ◽  
Standard Techniques

Standard techniques of electropolishing silver and silver alloys for electron microscopy in most instances have relied on various CN recipes. These methods have been characteristically unsatisfactory due to difficulties in obtaining large electron transparent areas, reproducible results, adequate solution lifetimes, and contamination free sample surfaces. In addition, there are the inherent health hazards associated with the use of CN solutions. Various attempts to develop noncyanic methods of electropolishing specimens for electron microscopy have not been successful in that the specimen quality problems encountered with the CN solutions have also existed in the previously proposed non-cyanic methods.The technique we describe allows us to jet polish high quality silver and silver alloy microscope specimens with consistant reproducibility and without the use of CN salts.The solution is similar to that suggested by Myschoyaev et al. It consists, in order of mixing, 115ml glacial actic acid (CH3CO2H, specific wt 1.04 g/ml), 43ml sulphuric acid (H2SO4, specific wt. g/ml), 350 ml anhydrous methyl alcohol, and 77 g thiourea (NH2CSNH2).

A High Resolution Scanning Microscope

1968 ◽  
Vol 26 ◽  
pp. 356-357
Author(s):  
A. V. Crewe ◽  
J. Wall ◽  
L. M. Welter
Keyword(s):  
High Resolution ◽  
Field Emission ◽  
Spherical Aberration ◽  
Focal Length ◽  
Spot Size ◽  
Emission Source ◽  
Field Of View ◽  
Scanning Microscope ◽  
Magnetic Lens ◽  
High Quality

A scanning microscope using a field emission source has been described elsewhere. This microscope has now been improved by replacing the single magnetic lens with a high quality lens of the type described by Ruska. This lens has a focal length of 1 mm and a spherical aberration coefficient of 0.5 mm. The final spot size, and therefore the microscope resolution, is limited by the aberration of this lens to about 6 Å.The lens has been constructed very carefully, maintaining a tolerance of + 1 μ on all critical surfaces. The gun is prealigned on the lens to form a compact unit. The only mechanical adjustments are those which control the specimen and the tip positions. The microscope can be used in two modes. With the lens off and the gun focused on the specimen, the resolution is 250 Å over an undistorted field of view of 2 mm. With the lens on,the resolution is 20 Å or better over a field of view of 40 microns. The magnification can be accurately varied by attenuating the raster current.

Sign in / Sign up

Export Citation Format

Share Document