SPARX, a MIMO Array for Ground-Based Radar Interferometry

Abstract

Ground-Based SAR Interferometry (GB-InSAR) is nowadays a proven technique widely used for slope monitoring in open pit mines and landslide control. Traditional GB-InSAR techniques involve transmitting and receiving antennas moving on a scanner to achieve the desired synthetic aperture. Mechanical movement limits the acquisition speed of the SAR image. There is a need for faster acquisition time as it plays an important role in correcting rapidly varying atmospheric effects. Also, a fast imaging radar can extend the applications to the measurement of vibrations of large structures. Furthermore, the mechanical assembly put constraints on the transportability and weight of the system. To overcome these limitations an electronically switched array would be preferable, which however faces enormous technological and cost difficulties associated to the large number of array elements needed. Imaging Multiple-Input Multiple Output (MIMO) radars can be used as a significant alternative to usual mechanical SAR and full array systems. This paper describes the ground-based X-band MIMO radar SPARX recently developed by IDS GeoRadar in order to overcome the limits of IDS GeoRadar’s well-established ground based interferometric SAR systems. The SPARX array consists of 16 transmit and 16 receive antennas, organized in independent sub-modules and geometrically arranged in order to synthesize an equally spaced virtual array of 256 elements.

Antenna Array for Ku-Band MIMO GB-SAR

“…Our proposed MIMO antenna has the highest gain, narrowest elevation HPBW, widest azimuth HPBW, and simplest structure. The number of transmitting and receiving elements is the highest, with the exception of [28]. However, our proposed antenna is superior in gain and radiation pattern characteristics.…”

Multi-Monostatic Interferometric Radar with Radar Link for Bridge Monitoring

“…The radar used is a modified version of IBIS-FM MIMO [12], developed by IDS Georadar, Pisa, Italy. Figure 6a shows the IBIS-FM MIMO with four antennas connected.…”

“…Monti-Guarnieri et al [9] operated two radars simultaneously to detect the displacement vector of corner reflectors fixed to a pipe. The recent introduction of multiple input, multiple output (MIMO) for spaceborne radar [10], for ground-based radar [11][12][13], and in biomedical contexts [14] has prompted the creation of new solutions. Deng et al [15] deployed three ground-based multiple input, multiple output (GB-MIMO) radar systems to measure 3D deformation of a movable corner reflector.…”

Special Issue “Synthetic Aperture Radar (SAR) Techniques and Applications”

“…The special issue includes also three interesting papers [8][9][10] dedicated to ground-based SAR (GBSAR) systems.…”

“…The first one [8] is a communication describing the Imaging Multiple-Input Multiple-Output (MIMO) ground-based interferometric radar developed in order to overcome the main limitations of traditional GBSAR systems, which are based on the mechanical movement of the antenna. The proposed system reduces data acquisition time, thus both limiting the atmospheric artefacts and extending the application to vibration measurements.…”