The landslide monitoring system consists of a network
of measurement units, denoted as sensor nodes, which are
situated directly on a sliding slope, tightly connected to the
moving terrain. In order to get reliable values concerning
the threat of large mass movements, the positions of the
sensor nodes are permanently monitored. This is achieved by
using GPS observations, acquired by GPS receivers attached to
the measurement units. The GPS observations (pseudorange,
Doppler, and phase measurements), together with data of other
sensors are transmitted to the data processing facility, denoted
as base station, which is located in the vicinity of the sensor
nodes but in a geological stable area. The combination of
sensor nodes and base station is denoted as sensor network.
An overview of the system is given in Fig.