4. Estimating Geodetic Parameters from GNSS

There are several parameter types in geodesy that have to be estimated, but whose values are interesting only for some special studies. GNSS phase ambiguities, clock parameters, and troposphere are examples of such parameter types. Moreover, if the user is interested only in one or particular type of parameters, all the others can be ignored after estimating them. On the basis of the definition of geodesy, (Geodesy, is the Earth science of accurately measuring and understanding Earth’s geometric shape, orientation in space, and gravitational field. The field also incorporates studies of how these properties change over time and equivalent measurements for other planets (https://​en.​wikipedia.​org/​wiki/​Geodesy).) geodetic parameters include, but are not limited to, station position coordinates and velocities; satellite position coordinates and velocities; baseline vectors; heights and height systems; the Earth’s orientation and its geocenter, the geoid, and other related quantities from gravity field measurements. These geodetic quantities (parameters) are derived (estimated) using precise measurements and the exact science of geodesy, for which GNSS is one of the widespread, globally accessible tools. This chapter is a quick overview of the concepts.