A New Tool for Airborne Gravimetry Survey Simulation

Daniele Sampietro,Ahmed Mansi,Martina Capponi

doi:10.3390/geosciences8080292

Daniele Sampietro, Ahmed Mansi + Show 1 more

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https://doi.org/10.3390/geosciences8080292

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Abstract

Airborne gravimetry represents nowadays probably the most efficient technique to collect gravity observations close to the Earth’s surface. In the 1990s, thanks to the development of the Global Navigation Satellite Systems (GNSS), which has made accurate navigational data available, this technique started to spread worldwide because of its capability to provide measurements in a fast and cost-effective way. Differently from other techniques such as shipborne gravimetry, it has the advantage to provide gravity measurements also in challenging environments which can be difficult to access otherwise, like mountainous areas, rain forests and polar regions. For such reasons, airborne gravimetry is used for various applications related to the regional gravity field modelling: from the computation of high accurate local geoid for geodetic applications to geophysical ones, specifically related to oil and gas exploration activities or more in general for regional geological studies. Depending on the different kinds of application and the final required accuracy, the definition of the main characteristics of the airborne survey, e.g., the planar distance between consecutive flight tracks, the aircraft velocity, etc., can be a difficult task. In this work, we present a new software package, which would help in properly accomplishing the survey design task. Basically, the developed software solution allows for generating a realistic (from the observation noise point of view) gravimetric signal, and, after that, to predict the accuracy and spatial resolution of the final retrievable gravimetric field, in terms of gravity disturbances, given the flight main characteristics. The proposed procedure is suited for airborne survey planning in order to be able to optimize the design of the survey according to the required final accuracy. With the aim to evaluate the influence of the various survey parameters on the expected accuracy of the airborne survey, different numerical tests have been performed on simulated and real datasets. For instance, it has been shown that if the observation noise is not properly modeled in the data filtering step, the survey results degrade about 25%, while not acquiring control lines during the survey will basically reduce the final accuracy by a factor of two.

Highlights

In recent decades, the airborne gravimetry technique has become more and more important for the acquisition of local gravity field data [1,2]
Thanks to this technological advancement, apart from the classical stabilized platform system, various measuring systems started to be deployed like the Strapdown Inertial Navigation System, which is based on a set of three orthogonal accelerometers and three gyroscopes or the system based on a combination of Global PositioningSystem (GPS) and Inertial
We move to a second simulation scenario: we considered in this case an area in Central Italy that extends between 11.95–12.65◦ East and 41.15–41.85◦ North, and we tried to retrieve the survey parameters minimizing the flight time, but always assuring an accuracy better than 1 mGal, i.e., simulating a possible scenario for the design of an airborne survey for exploration activities or regional geological investigations

Summary

Introduction

The airborne gravimetry technique has become more and more important for the acquisition of local gravity field data [1,2] This is due to the fact that it permits investigating large areas, of about 100 km× 100 km, by a few days survey and at a relatively low cost, if compared to other techniques, such as ground point-wise measurements, which can be quite time consuming and expensive. Another advantage of using this technique is linked to the possibility of performing. Thanks to this technological advancement, apart from the classical stabilized platform system, various measuring systems started to be deployed like the Strapdown Inertial Navigation System, which is based on a set of three orthogonal accelerometers and three gyroscopes or the system based on a combination of GPS and Inertial

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