Geo Lab.

The laboratory of the Geomatics Division provides the equipment required to boost research in the division’s field of work.

The laboratory is equipped not only with common equipment like oscilloscopes or signal generators but also with a wide variety of “GEO” sensors and instruments, as for instance, an interferometric radar, Inertial Measurement Units (IMUs), Global Navigation Satellite System (GNSS) receivers or imaging sensors.

One of the main measuring systems available at GeoLab is an interferometric radar system, applied for remote sensing monitoring in several national and international research projects. This apparatus is a commercial system, and can be used in two different measuring configurations. The first one is as a Real Aperture Radar (RAR), with acquisition performances aimed at sampling vibrations in the range of 01. Hz to 100 Hz. In this setup the transceiver is mounted on a fixed tripod and it is used to monitor the dynamical behavior of structures as: bridge, tower, tall buildings etc. The second one is using it as a Ground Based Synthetic Aperture Radar (SAR). In this case the transceiver moves along a linear rail, and for each mechanical scanning it is able to provide a SAR image of a few kilometer square areas, to monitor slow deformations of the terrain, slopes, landslides or dam, mines etc., every approximately eight minutes. The main characteristics of the radar transceiver are here resumed. The transceiver is a Continuous Wave step-frequency radar operating in Ku band, with a Radio Frequency band selectable between 17.1 GHz and 17.3 GHz. The Maximum EIRP is 26dBm. Antennas can be changed: three pairs with different gain and pattern are available. A picture taken during a GBSAR data collection is shown in fig.1.

 

 

Fig. 1: Picture of the radar system in GB SAR configuration during a measurement campaign in Barcelona.

Fig. 1: Picture of the radar system in GB SAR configuration during a measurement campaign in Barcelona

As accessories of the radar system, different sets of radar reference reflectors (Corner Reflectors) are available. Data acquired through the interferometric radar systems can be processed by means of software tools available from the system provider or through original home developed processing tools at the division.

Besides the usual tasks performed in a technical laboratory, the GeoLab personnel works also in the integration of hardware, instruments, sensors and software for data acquisition and processing purposes. Such tasks have led to the birth of several generations of a Trajectory, Attitude and Gravimetry provider system (TAG, mTAG, µTAG see fig. 2). The self-developed TAG family systems have proven extremely useful to support the positioning and navigation division’s fields of research. This technology, as well, has been instrumental to increase the participation of the division in research, advanced development and technology transfer projects.