Stefano Lischi

Advanced Polarimetric Doppler Weather Radar Simulator

The Advanced Polarimetric Doppler Weather Radar Simulator (APDWRS) capable of generating I&Q time series voltages for a ground based fully-polarimetric Doppler weather radar is described in this paper. The Weather Research and Forecast (WRF) model is used in conjunction with the T-Matrix code to generate radar signals according to the propagation-modified covariance matrix. Mixtures of rain, hail, graupel and snow hydrometeors relative to a realistic weather phenomenon are considered. The polarimetric and Doppler observables estimated from the simulated radar signals showed a good agreement with those found in previous observations.

3D InISAR-based target reconstruction algorithm by using a Multi-Channel ground-based radar demonstrator

A 3D reconstruction algorithm for non cooperative moving targets is proposed in this paper. This method exploits interferometric ISAR imaging (InISAR) to estimate the heights of the dominant scatterers with respect t o the Image Projection Plane. In particular, the interferometric phases measured from two orthogonal baselines are used to reconstruct t he third dimension from 2D-ISAR images. Some aspects that make such approach effective in a real scenario have been faced and their problems solved. In order to verify the effectiveness and the reliability of this technique, data from a suitably designed Multi-Channel ground-based radar has been used.

Validation of the Advanced Polarimetric Doppler Weather Radar Simulator with Polar55C real observations

A preliminary validation of the Advanced Polarimetric Doppler Weather Radar Simulator (APDWRS) with real data is described in this paper. The APDWRS is used to reproduce an observation of a severe storm event which took place on the 15th of October 2012 over the Tyrrenian coast. One PPI scan performed by the dual polarization C-band Polar 55C weather radar at 17:30 UTC is simulated using APDWRS with meteorological data from the Weather Research and Forecast (WRF) model as input. The validity of the simulation is then compared both in the spatial domain and statistically observing the differences in the relationships between observables in real and simulated case.

Low Cost FMCW Radar Design and Implementation for Harbour Surveillance Applications

The prototype of a low power radar with a coverage range from some hundred meters to a few kilometres is presented in this paper. A Frequency Modulate Continuous Wave (FMCW) X-band solution has been chosen from the architectural point of view, and an hybrid realization has been adopted. In fact, one of the main target of the design was to demonstrate the feasibility of high sensitivity radar sensor implemented in a low cost technology. Some original solutions have been adopted to reach this target. The radar prototype is composed by a radio frequency front end, entirely realized by using commercial components, and by a DSP platform implemented by using open source software. The prototype has been realized and tested. The main interesting results are: (i) the low cost of the radio frequency front end; (ii) the high sensitivity of the sensor which resulted capable of monitoring the movements of object and peoples in a range of some hundred meters with a transmitted power as low as a few mW; (iii) a very low level of EM pollution; (iv) a coverage range of 1 mile with an output power of 2 W; (v) the detection of range and velocity for targets with a radar cross section larger than 1 m inside the coverage range. The main application will be as a node of a radar network for harbour surveillance.

Soft 3D-ISAR image reconstruction using a dual interferometric radar

A soft 3D reconstruction algorithm for non cooperative moving targets is proposed in this paper. This method exploits a dual interferometric ISAR system (InISAR) to estimate the heights of the dominant scatterers with respect to the Image Projection Plane (IPP). In particular, the interferometric phases measured from two orthogonal baselines are used to reconstruct both the third dimension from 2D-ISAR images and the IPP. A Cross-Channel Coherence-based detection is used in order to take into account only the areas of the target with meaningful interferometric phase. In order to verify the effectiveness and the reliability of this technique, a Multi-Channel ground-based radar has been used.

Precipitation sensing experiment with a prototype dual-polarization weather radar for civil aircraft

The European Commission initiative CleanSky launched several project activities aimed at improving flight route planning in the presence of unforeseen events, such as rapidly evolving thunderstorms occurring along the route, both to increase the safety and comfort of flight and to keep emissions as low as possible. Improving meteorological instrumentation onboard and supporting the pilot in interpreting such goals are important to achieve this goal. Potential improvements to aircraft weather radar related to the use of dual opalization technology were investigated along several CleanSky projects. Two experimental campaigns, were carried out in 2016 within the X-WALD project with a prototypal radar using a low-power X-band dual-polarization radar mounted in the nose of two different aircrafts in the Netherlands and in Italy. Results from these campaigns and comparison of data collected on board with ground-based instrumentation are presented.

The X-WALD project: First measurements in Europe with an avionic polarimetric weather radar

The X-WALD project was launched to run ad hoc airborne measurements finalized to investigate the potentials of polarimetry in weather radars for civil aircrafts. In this contribution, the outcome of the project will be presented, and in particular the results of two measurements campaigns, carried out in The Netherlands and in Italy, using a low-power X-band fully polarimetric radar mounted in the nose of two different aircraft.