5. Generating Time Series and Velocity Fields

When input to GLOBK as quasi-observations, h-files can be considered either individually (glred) to generate time series or as a group (globk) to estimate positions and velocities. In either case the most important decisions facing the analyst are how to edit and weight the data and how to define and realize the reference frame. In making these decisions, you need to consider what stations to include explicitly, how to treat the orbits and Earth orientation parameters (EOP), and practical constraints on computation speed and data storage. In this chapter we discuss strategies you might use to achieve your analysis objectives with the tools available in the GLOBK suite of programs. The computation of multi-year solutions may be carried out conveniently in a directory (e.g. vsoln/) parallel to the directories used for each survey or year of continuous data. At this same level, you may want to create an additional tables/ directory containing files common to all the years and the velocity solutions. If you carry out a series of multi-year analyses, then command files in additional processing directories (asoln/, bsoln/, etc.) can use the same path (../tables/) to these common files.