New concepts for airborne gravity measurement

2001 ◽  
Vol 5 (6) ◽  
pp. 413-424 ◽  
Author(s):  
Fethi Abdelmoula
Geophysics ◽  
1984 ◽  
Vol 49 (3) ◽  
pp. 311-311
Author(s):  
Sigmund Hammer

Dr. Steenland’s principal criticism arises from an unfortunate overstatement, in my paper, of the precision and anomaly resolving power of the Carson Airborne Gravity method. This criticism is well deserved. My calculation of the probable error of an airborne gravity measurement was based on many thousands of Δg gravity differences at grid‐line intersections, but it made the implicit assumption that the two reported gravity values at each grid intersection were independent. This is incorrect because the grid system of intersection differences is used for controls in the data processing. A realistic value for the probable error of an airborne gravity measurement is of the order of 1 mgal (standard deviation of 1.5 mgal). The associated resolving power for gravity anomalies, above this magnitude, is of the order of 2 to 3 miles (3 to 5 km) at flight speed of 50 knots. Smaller anomalies may be resolved at lower speeds.


2018 ◽  
Vol 17 (1) ◽  
pp. 7-15
Author(s):  
Niraj Manandhar ◽  
Shanker K.C.

Gravimetric geoid plays the important role in the process of local/regional geoidal undulation determination. This approach uses the residual gravity anomalies determined by the surface gravity measurement using the gravimeter together with best fit geopotential model, with the geoid undulations over the oceans determined from the method of satellite altimetry. Mass distribution, position and elevation are prominent factors affecting the surface gravity. These information in combination with geopotential model helps in satellite orbit determination, oil, mineral and gas exploration supporting in the national economy. The preliminary geoid thus computed using airborne gravity and other surface gravity observation and the accuracy of computed geoid was likely at the 10-20cm in the interior of Nepal but higher near the border due to lack of data in China and India. The geoid thus defined is significantly improved relative to EGM –08 geoid.


1990 ◽  
Vol 17 (11) ◽  
pp. 1941-1944 ◽  
Author(s):  
John Brozena ◽  
John LaBrecque ◽  
Mary Peters ◽  
Robin Bell ◽  
Carol Raymond

2021 ◽  
Vol 13 (20) ◽  
pp. 4157
Author(s):  
Guoqing Ma ◽  
Tong Gao ◽  
Lili Li ◽  
Taihan Wang ◽  
Runxin Niu ◽  
...  

Airborne (or satellite) gravity measurement is a commonly used remote sensing method to obtain the underground density distribution. Airborne gravity gradiometry data have a higher horizontal resolution to shallower causative sources than airborne gravity anomaly, so joint exploration of airborne gravity and its gradient data can simultaneously obtain the anomaly feature of sources with different depths. The most commonly used joint inversion method of gravity and its gradient data is the data combined method, which is to combine all the components into a data matrix as mutual constraints to reduce ambiguity and non-uniqueness. In order to obtain higher resolution results, we proposed a cooperate density-integrated inversion method of airborne gravity and its gradient data, which firstly carried out the joint inversion using cross-gradient constraints to obtain two density structures, and then fused two recovered models into a result through Fourier transform; finally, data combined joint inversion of airborne gravity, and gradient data were reperformed to achieve high-resolution density result using fused density results as a reference model. Compared to the data combined joint inversion method, the proposed cooperate density-integrated inversion method can obtain higher resolution and more accurate density distribution of shallow and deep bodies meanwhile. We also applied it to real data in the mining area of western Liaoning Province, China. The results showed that the depth of the skarn-type iron mine in the region is about 900–1300 m and gives a more specific distribution compared to the geological results, which provided reliable data for the next exploration plan.


Geophysics ◽  
1988 ◽  
Vol 53 (2) ◽  
pp. 245-253 ◽  
Author(s):  
John M. Brozena ◽  
Mary F. Peters

The Naval Research Laboratory (NRL) has developed a prototype airborne gravity measurement system. The core of the system is a LaCoste and Romberg air‐sea gravity meter mounted on a three‐axis stable platform. Corrections to the gravimeter data for altitude and variations in altitude are determined from a combination of highly precise radar and pressure altimeters. The original prototype system was designed for use over oceanic areas. We recently incorporated the pressure measurement to extend use of the airborne system to terrestrial regions where occasional radar altitudes over points of known topographic height can be obtained. The radar heights are used to relate the pressure altitudes to absolute altitudes and to determine the slopes of the isobaric surfaces. Vertical accelerations due to horizontal velocity over a curved, rotating earth (the Eötvös correction) and precise two‐dimensional positions are determined from a Texas Instrument P-code global positioning system. The updated system was tested over eastern North Carolina and the Outer Banks, an area that is difficult to survey by conventional means. Over one‐third of the region consists of low lying swampy terrain and another one‐third is the shallow water of the Pamlico and Albemarle Sounds. Neither the land method nor the shipboard gravity surveying method is well suited for these types of areas. Flying at an altitude of 600 m at 375 km/hr, we were able to cover an area over [Formula: see text] with a nominal track spacing of 9 km by 9 km in less than 18 hours of flying time. A comparison by the Defense Mapping Agency showed a 2.8 mGal rms and a −0.2 mGal mean difference between ground truth data and the airborne data at grid points when both data sets were interpolated to a common 9 km grid.


2014 ◽  
Vol 5 (4) ◽  
pp. 68-72 ◽  
Author(s):  
Yan Xincun ◽  
Ouyang Yongzhong ◽  
Sun Yi ◽  
Deng Kailiang

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