Comparison of MAGSAT and low-level aeromagnetic data over the Canadian Shield: implications for GRM

1985 ◽  
Vol 22 (9) ◽  
pp. 1241-1247 ◽  
Author(s):  
J. Arkani-Hamed ◽  
D. W. Strangway ◽  
D. J. Teskey ◽  
P. J. Hood
Keyword(s):  
Magnetic Anomaly ◽  
Canadian Shield ◽  
Geological Mapping ◽  
Aeromagnetic Data ◽  
Research Mission ◽  
Geological Features ◽  
Order Of Magnitude ◽  
Band Limited ◽  
Anomaly Map ◽  
The One

Band-limited magnetic anomalies over the Canadian Shield, for wavelengths of ~500–2200 km, derived from the magnetometer satellite (MAGSAT) data correlate peak for peak with the corresponding anomalies derived from the aeromagnetic data. This suggests that the anomalies detected by MAGSAT are physically meaningful. A new potential field satellite, Geopotential Research Mission (GRM), has been proposed to fly at about 160 km altitude. The magnetic anomaly map that can be derived from the GRM data is expected to have a resolution about an order of magnitude higher than the one derived from MAGSAT data. A magnetic anomaly map of the Canadian Shield, which is expected to derive from the GRM data, is shown based on the aeromagnetic data. The map delineates many major geological features quite clearly and illustrates the importance of the GRM mission for global geological mapping.

Presentation of magnetic anomaly map data by stereo projection of magnetic shadowgrams

1985 ◽  
Vol 22 (2) ◽  
pp. 311-314 ◽  
Author(s):  
John Broome ◽  
Réjean Simard ◽  
Dennis Teskey
Keyword(s):  
Magnetic Anomaly ◽  
Geological Mapping ◽  
Geological Survey ◽  
Magnetic Data ◽  
Stereo Pair ◽  
Magnetic Intensity ◽  
Fine Detail ◽  
Anomaly Map ◽  
Map Data ◽  
Shaded Relief

Coloured magnetic maps published at the 1:1 000 000 scale by the Geological Survey of Canada have been found to be useful aids in support of regional geological mapping and compilation projects. However, because of the quantization into colour intervals, some of the fine detail contained in the original magnetic data is lost. These smaller features can be brought out quite effectively with the shaded relief technique, although there is an attendant loss of amplitude information, which can be recovered by means of stereo-shadowgrams. A second shadowgram is produced by offsetting the original shadowgram by an amount proportional to the magnetic intensity of each data point and then the offset and original shadowgrams are viewed as a stereo pair. An example of the effectiveness of these techniques is the detail that can be seen on the shadowgrams and stereo-shadowgrams for the Lockhart River (IMW NP 12/13) and the Thelon River (IMW NQ 12/13/14) map sheets.

U.S. National Magnetic Anomaly Survey Specifications Workshop Report

Geophysics ◽  
1979 ◽  
Vol 44 (5) ◽  
pp. 991-992
Author(s):  
William J. Hinze
Keyword(s):  
Magnetic Anomaly ◽  
North American ◽  
Executive Committee ◽  
Ad Hoc ◽  
Magnetic Data ◽  
Aeromagnetic Data ◽  
Workshop Report ◽  
The North ◽  
Anomaly Map ◽  
The U.S

The National Magnetic Anomaly Map (NMAM) Committee, which was formed as an ad hoc committee in 1975 by the SEG Executive Committee, has recommended a multistage program for improving the aeromagnetic data of the U.S. On behalf of the geoscience community, the committee and the U.S. Geological Survey are currently engaged in the preparation of a photo‐composite map of the U.S. derived from publicly available data plus regional magnetic data contributed from the private sector. This map is at present being compiled and is to be pulished by the U.S.G.S. at a scale of [Formula: see text]. Eventually, utilizing this map, the committee plans to assist in the preparation of a North American magnetic anomaly map to supplement the North American tectonic map and the proposed continental gravity anomaly map.

Band-limited global scalar magnetic anomaly map of the Earth derived from Magsat data

1986 ◽  
Vol 91 (B8) ◽  
pp. 8193 ◽  
Author(s):  
J. Arkani-Hamed ◽  
D. W. Strangway
Keyword(s):  
Magnetic Anomaly ◽  
The Earth ◽  
Band Limited ◽  
Anomaly Map

Theoretical studies on the one- and two-photon absorption of tetrabenzoporphyrins and phthalocyanines

2004 ◽  
Vol 82 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Xin Zhou ◽  
Ai-Min Ren ◽  
Ji-Kang Feng ◽  
Xiao-Juan Liu
Keyword(s):  
Dipole Moment ◽  
Cross Sections ◽  
Density Functional ◽  
Transition Dipole Moment ◽  
Photon Absorption ◽  
Transition Dipole ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Order Of Magnitude ◽  
The One

The one-photon absorption (OPA) properties of tetrabenzoporphyrins (TBPs) and phthalocyanines (Pcs) were studied using the semiempirical ZINDO method and time-dependent density functional theory (TDDFT), respectively. The compared results confirmed that the semiempirical ZINDO method was reasonably reliable when calculating the OPA of tetrabenzoporphyrins and phthalocyanines. On the basis of the OPA properties obtained from the ZINDO method, two-photon absorption (TPA) properties of two series of molecules were investigated, using ZINDO and sum-over-states (SOS) methods. The results showed that the TPA cross-sections of all molecules were in the range of 220.6 × 10–50 – 345.9 × 10–50 cm4·s·photon–1, which were in the same order of magnitude as the values reported in the literature. The relatively larger δ(ω) value for Pcs with respect to that for corresponding TBPs originates from larger intramolecular charge transfer, which can be characterized by the difference of dipole moment between S0 and S1 and the transition dipole moment between S1 and S5.Key words: two-photon absorption, ZINDO, sum-over-states, tetrabenzoporphyrin, phthalocyanines.

Observations of the Earth’s resources

1969 ◽  
Vol 308 (1493) ◽  
pp. 173-182 ◽  
Keyword(s):  
Mineral Exploration ◽  
Geological Mapping ◽  
The Other ◽  
Ground Control ◽  
Great Contribution ◽  
Know How ◽  
Control Information ◽  
The World ◽  
The One ◽  
Effective Development

In attempting to present some observations on the kind of information on the Earth’s resources which may be obtained from spacecraft and space satellites, I think I should explain that I speak as a geographer with research interests in the field of biogeography/geobotany where I have been concerned with the use of vegetation in mineral exploration work and in the assessment of land potential for agricultural and other uses. In the course of this work I have come to appreciate major problems of regional or even continental dimensions and have become aware of the great potential offered by suitably equipped Earth resources satellites for providing information which would assist their solution. At the same time I have come to recognize the great contribution which Earth resources satellites can make in the fields of agriculture, forestry and conservation, topographical and geological mapping, hydrology, oceanography, land use and urban planning, to mention but a few. As a setting for my subsequent remarks I would like to state what I believe to be the relative positions of the U. S. A. and the U. S. S. R. on the one hand and this country and certain West European countries on the other with regard to the acquisition of information from Earth resources satellites. America and Russia have led the world in space research. They have the resources, the facilities and the technical know-how for placing spacecraft and satellites in orbit. For the effective development of Earth resources satellites, however, ground control information is essential. Here this country, together with member and former member countries of the Commonwealth possesses a body of people scattered through universities, government departments and organizations, commerce and industry whose firsthand knowledge of remote terrain in many parts of the world is unrivalled. This knowledge harnessed into an Earth resources satellites programme could enable this country to make a leading contribution to the development of the less developed parts of the world and at the same time materially assist the economy of this country.

scholarly journals Magnetic anomaly map (residual total field), Geraldton, Ontario

1988 ◽  
Author(s):  
Keyword(s):  
Magnetic Anomaly ◽  
Total Field ◽  
Anomaly Map
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