Potential of Using Airborne Geophysical Survey Data for Geodetic Applications

Abstract

The new realization of the Brazilian Height Reference System (RVRB) in 2018, aiming at its modernization, incorporated gravimetric data on the geometric leveling lines. Thus, the vertical coordinates are geopotential numbers, part referred to Imbituba Vertical Datum (DVB-I), part referred to Santana Vertical Datum (DVB-S). Complementary to the modernization process It is also necessary to physically connect the two network segments and refer them to the International Height Reference System (IHRS). However, RVRB still has technical limitations such as: heterogeneous spatial distribution; existence of extensions making their integral adjustment unfeasible; and insufficient gravimetric observations associated with leveling lines. Due to the difficulty of access in the RVRB segment connection area, it is necessary to look for alternatives for measuring or predicting gravity values. In this context, properly performed airborne gravimetry allows the obtaining of gravimetric data compatible with the precision, resolution and spatial distribution requirements necessary for geodesy. Thus, we sought to verify the potentialities of the geodetic use of gravimetric functional provided by Airborne Geophysical Survey conducted in the States of Amapá and Pará. Then, with a specific methodology, using: gravity values ​​observed at flight height; altitude values ​​from a Digital Altitude Model (DEM) and functional values ​​obtained from a Global Geopotential Model (GGM). New values ​​were calculated and compared with those available in the contracted survey database. It was concluded that the aerial lift functional is not suitable for geodetic applications, while the functional ones calculated with geodetic specifications in the present work overcome these deficiencies.