Estimation of the Argentinean Vertical Datum Parameter with Respect to the International Height Reference Frame (IHRF)

Abstract

AbstractOne of the current goals of the International Association of Geodesy (IAG) through its Global Geodetic Observing System (GGOS) is the unification of the existing local vertical datums towards the realization of the International Height Reference System (IHRS), i.e. the International Height Reference Frame (IHRF). To achieve this goal, one possible solution is to compute the offset between the equipotential surface of the Earth’s gravity field realized by the conventional $$W_0^{\text{IHRF}}$$ W 0 IHRF value of the IHRS and the unknown geopotential value of the local vertical datum. This offset is known as vertical datum parameter. In this study, the determination of the vertical datum parameter of the Argentinean National Vertical Reference System 2016 (SRVN16) using two approaches is presented. The first approach is based on the Geodetic Boundary Value Problem (GBVP). The second approach combines geopotential numbers obtained with levelling and gravity with geopotential numbers derived from a quasigeoid model. Both methods require GNSS/Levelling data and a high-precision gravimetric quasigeoid model. The quasigeoid model was computed using the remove-compute-restore technique and applying a Fourier representation of Molodensky’s integral formula. The vertical datum parameter estimation was carried out in a flat area in the Buenos Aires province due to the availability of high-quality gravity observations and benchmarks with GNSS/Levelling-derived height anomalies, all located near the tide gauge station used to define the Argentinean vertical datum. Estimation results with the first and second approach were $$-0.46 \pm 1.78 \text{ m}^2\text{s}^{-2}$$ − 0.46 ± 1.78 m 2 s − 2 and $$-0.46 \pm 1.37\ \text{m}^2\text{s}^{-2}$$ − 0.46 ± 1.37 m 2 s − 2 , respectively. The vertical datum parameter can be further used to integrate SRVN16 into the IHRF.