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
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.
Fig.2 µTAG system
The hardware, instruments or sensors integrated range from commercial computers, microcontrollers, MEMs devices, IMUs (from navigation to consumer grade), GNSS receivers, cameras or LIDAR sensors. Software is developed typically using C or C++, on regular, real-time or deterministic operating systems.
Other GeoLab noticeable tasks include camera calibration, using self-developed software and the GeoLab imaging sensors calibration field facility (see Fig 3.) or the participation in surveying campaigns.
Fig.3 Calibration field
Some of the projects where the cooperation of the lab personnel has been of some importance are GINSEC, PERIGEO, GAL, DECIVEL, FLUXPYR, GeoTRAM, and CLOSE-SEARCH.
Abridged list of available equipment:
GB SAR Interferometric system, model Ibis L/S, manufactured by IDS Pisa –Italy including:
- IBIS radar sensor (Ku band coherent transceiver).
- Antennas (3) with different gain.
- Power supply unit.
- 2 lead sealed batteries 12V 70 Ah.
- 3 gel lead sealed batteries 12 V 12 Ah.
- Panasonic CF-19 laptop with power unit.
- Linear Rail with motor.
- Height varying mechanical module.
- Elevation pointing system.
- Optical Telescope.
- Positioning frame.
Self-developed acquisition systems for trajectory determination purposes.
- mTAG (PC104+ technology for real-time determination of time, position, velocity and attitude. The mTAG system acquires from IMUs, GNSS receivers, barometer and magnetometer sensors)
- µTAG (Microcontroller technology for real-time acquisition of a single GNSS receiver and up to two industrial grade IMUs)
- VISIONA (Small computer technology for real-time acquisition of digital cameras and LIDAR sensors)
Inertial Measurement Units (IMUs)
- Navigation grade ( IMAR FJI )
- Tactical grade (Litton LN200 and IGI IIE)
- Industrial grade (EVAL-ADIS 16488 and two Epson S4E5A0A0A1)
GNSS receivers and antennas:
- Javad TR-G3T GNSS receiver – L1/L2/L5E
- Novatel OEM-V GNSS receiver (x2) – L1/L2/L5E
- Trimble 5700 GNSS receiver (x2) – L1/L2
- Novatel GNSS antennas (x4) – L1/L2
- Trimble Zephir antennas (x2) – L1/l2
- Aviation GNSS antenna – L1/L2/L5
Other sensors:
- Magnetometer
- Barometer
- Odometer
Cameras and lens:
- Prosilica GE4900c industrial color camera – 16 Mpx
- Prosilica GC2450 industrial monochromatic camera – 5 Mpx
- Sony NEX-5N Evil camera – 16 Mpx
- Sony lens (x2) – E-mount
- Carl Zeiss lens – F-mount
- Nikon lens – F-mount
Geodetic and surveying instruments / equipment
- Trimble total station
- Levels
Digital Photogrammetric station