# A New Tool for Airborne Gravimetry Survey Simulation

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## Abstract

**:**

## 1. Introduction

^{2}) at a spatial resolution of 5–6 km [1]. 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 Measurement Units, used to determine all the components of the gravity vector [5,6,7,8]. Nowadays, even if different research groups were able to show that strapdown systems can basically produce the same gravity quality of the stabilized platform one [1,9,10] (also for production-oriented campaigns under challenging conditions), the latter is still considered as the standard technique, especially for geophysical applications.

## 2. Methodology

^{3}kg

^{−1}s

^{−2}, M is the Earth mass ($5.972\times {10}^{24}$ kg), a is the Earth semi-major axis (taken here equal to 6,378,137 m), ${P}_{\ell m}$ is the fully normalized associate Legendre function of degree m and order ℓ, and $\left(\lambda ,\phi ,r\right)$ are the geocentric coordinates of the point in which $\delta {g}_{GGM}$ should be computed.

- observation along the same flight line are correlated, while observations of different flight lines are supposed to be independent;
- the observation noise is zero mean and stationary, namely ${\mu}_{\nu}=0$ and ${C}_{\nu \nu}={C}_{\nu \nu}\left(d\right)$, where d is the distance between two points on the same flight line.

## 3. Numerical Tests

^{2}and a correlation length of about $0.05\xb0$ corresponding to $5.2$ km.

## 4. Conclusions

## Author Contributions

## Funding

## Acknowledgments

## Conflicts of Interest

## References

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**Figure 2.**The proposed processing scheme to estimate the final predicted accuracy of a simulated airborne survey.

**Figure 4.**Empirical covariance retrieved from the CarbonNet dataset by means of the crossover analysis (red points), and theoretical covariance used to simulate data (light blue solid line).

**Figure 5.**Reference field (

**left**) and simulated observations (

**right**).The black line represents the shoreline, where the land is located in the northwest and the sea in the south. Unit [mGal].

**Figure 6.**Difference between the estimated field and the reference one (

**left**) and predicted accuracy from the simulated data (

**right**). The black line represents the shoreline, where the land is located in the northwest and the sea in the south. Unit [mGal].

**Figure 7.**Signal power spectrum (green line), compared with the theoretical power spectrum of a white noise with standard deviation equal to $0.67$ mGal (red line), 1 mGal (blue line), and $1.4$ mGal (black line).

Test ID | Aircraft Velocity [m/s] | Traverse Lines Spacing [m] | Control Lines Spacing [m] | Flight Time Time [h] | Accuracy Mode Mode [mGal] |
---|---|---|---|---|---|

1 | 50 | 1000 | 10,000 | 52.9 | 0.67 |

2 | 65 | 1000 | 10,000 | 40.5 | 0.95 |

3 | 75 | 1000 | 10,000 | 35.1 | 0.96 |

4 | 85 | 1000 | 10,000 | 30.9 | 1.05 |

5 | 100 | 1000 | 10,000 | 26.3 | 1.03 |

6 | 50 | 2500 | 10,000 | 22.7 | 1.10 |

7 | 50 | 5000 | 10,000 | 12.6 | 1.22 |

8 | 50 | 7500 | 10,000 | 9.2 | 1.37 |

9 | 50 | 10,000 | 10,000 | 7.5 | 1.44 |

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**MDPI and ACS Style**

Sampietro, D.; Mansi, A.H.; Capponi, M.
A New Tool for Airborne Gravimetry Survey Simulation. *Geosciences* **2018**, *8*, 292.
https://doi.org/10.3390/geosciences8080292

**AMA Style**

Sampietro D, Mansi AH, Capponi M.
A New Tool for Airborne Gravimetry Survey Simulation. *Geosciences*. 2018; 8(8):292.
https://doi.org/10.3390/geosciences8080292

**Chicago/Turabian Style**

Sampietro, Daniele, Ahmed Hamdi Mansi, and Martina Capponi.
2018. "A New Tool for Airborne Gravimetry Survey Simulation" *Geosciences* 8, no. 8: 292.
https://doi.org/10.3390/geosciences8080292