Evaluation of Terrestrial and Airborne Gravity in Determining Gravity Anomalies and the Geoid in Colorado, USA

Every point on Earth has a specific gravity and gravity potential value. Surfaces that connect points with equal gravity potential are referred to as equipotential or level surfaces. Among these, the geoid—an equipotential surface that closely approximates mean sea level—plays a fundamental role in the study of the Earth's gravity field within the framework of physical geodesy. However, gravity measurements obtained on the Earth's physical surface cannot be used directly; they must first be transformed into gravity anomalies to enable meaningful geophysical and geodetic analysis.

This paper evaluates the free-air and simple Bouguer gravity anomalies derived from both terrestrial and airborne gravity measurements. The consistency between terrestrial and airborne gravity-derived anomalies is also examined to assess the advantages of integrating multi-source datasets for regional gravity field modeling. Moreover, the study investigates how the selection of gravity anomaly type affects the accuracy, resolution, and overall reliability of the gravimetric geoid in a mountainous area of the Colorado test region. The results contribute to a better understanding of gravity anomaly behavior in complex topographic environments and provide insights into improving regional geoid determination strategies.