The values of those different amounts are related of the following form: ZTD = ZHD + ZWD and all those amounts here presented refer the surface physics of the Earth on continental areas and to mean sea level on oceanic ones.
To obtain the values of the forecasts for any point within the area covered by the product, download the package interpolator for Windows or Linux and download the binaries for the time of interest.
NOTICES:New interpolators available on Windows and Linux systems using the 15km Eta model forecasts every 3 hours on South America.