The determination of the height of a structure above mean sea level is necessary for many applications such as the construction of canals, dams and coastal defenses and maps. Traditionally, heights are observed using geodetic levelling by measuring height differences between several points, benchmarks, along lines that cover the country. These levelling lines start at the tide gauge that defines the zero height.

Geodetic levelling can achieve millimeter accuracy, but it is a costly and time-consuming process. Currently the best approach at national level is the creation of geoid undulation models that permit to have consistent heights all over the entire territory of a country directly estimated from GNSS observations.

These models should be connected to tide-gauges to establish a physical reference to the geoid undulation model. MIRASpaco has experience in the installation of tide-gauges together with the determination of the height difference between the water level and nearby geodetic benchmarks to define the vertical datum.

Services offered by MIRASpaco:

• Gravity campaigns;
• Geoid Computation;
• Installation of tide gauges.