A new numerical procedure has been developed for removing tidal and atmosph
eric effects from Earth deformation measurements. It was developed in order
to manage semi-automatically sequences that are usually difficult to analy
se such as very long records, slow earthquakes and volcanic eruptions. Even
ly and unevenly spaced time sequences can be analysed for tidal deformation
as well as for long-term drift and atmospherically induced terms, even if
there are large gaps in the data set. Its performance has been tested by an
alysing two experimental sequences, one including slow earthquakes and the
other an eruption. The results have been compared with those obtained by us
ing the two most widely used codes.