G. Artese

POIS, a Low Cost Tilt and Position Sensor: Design and First Tests

An integrated sensor for the measurement and monitoring of position and inclination, characterized by low cost, small size and low weight, has been designed, realized and calibrated at the Geomatics Lab of the University of Calabria. The design of the prototype, devoted to the monitoring of landslides and structures, was aiming at realizing a fully automated monitoring instrument, able to send the data acquired periodically or upon request by a control center through a bidirectional transmission protocol. The sensor can be released with different accuracy and range of measurement, by choosing bubble vials with different characteristics. The instrument is provided with a computer, which can be programmed so as to independently perform the processing of the data collected by a single sensor or a by a sensor network, and to transmit, consequently, alert signals if the thresholds determined by the monitoring center are exceeded. The bidirectional transmission also allows the users to vary the set of the monitoring parameters (time of acquisition, duration of satellite acquisitions, thresholds for the observed data). In the paper, hardware and software of the sensor are described, along with the calibration, the results of laboratory tests and of the first in field acquisitions.

Compact wireless GPS/inertial system

This paper reports the state of works in the development of a wireless, low-cost, inertial-georeferencial system, designed to evaluate the obtainable performance in aerial photogrammetry direct georeferencing applications. It integrates an advanced tri-axial inertial sensor with a GPS and a wireless module. A low-cost camera has been also interfaced. The information management is carried out by two 8bit microcontrollers; synchronization, data handling and communication between them and the functional blocks is managed in order to optimize the data transmission throughput. In building the prototype, particular effort has been spent to minimize size and weight and to increase battery autonomy. A PC interface, allowing for parameters control and data logging, completes the system. The reported preliminary testing results point out the system potentialities and let to foresee a wide field of applications.

GPS Measurements in the Neapolitan volcanic area

Abstract The surveillance of the Neapolitan volcanic area (Mt. Vesuvius, the Phlegrean Fields and the island of Ischia) represents the principal activity of the Osservatorio Vesuviano. Such an activity is carried out also through the study of ground deformations. This study deals with the use of the GPS as a powerful topographic technique. In the last two years, three GPS networks in the above mentioned area were established, with 8 vertices at Mt. Vesuvius, 20 vertices in the Island of Ischia and 30 vertices in the Phlegrean Fields. In Mt. Vesuvius area a GPS test was carried out, in order to verify the possibility of the installation of a network of GPS permanent stations. In the island of Ischia, three different GPS techniques (Static, Fast Static and RTK-Real Time Kinematics) have been used to get a first set of coordinates and to carry out a comparison between these in small extension areas. GPS data of the Phlegrean Fields are still in processing. The results for Mt. Vesuvius area and the island of Ischia are hereby presented and discussed.