Ricerc@Sapienza

The IUCN (International Union for Conservation of Nature) Red List categories and criteria are the most widely used framework for assessing the relative extinction risk of species. The criteria are based on quantitative thresholds relating to the size, trends, and structure of species’ distributions and populations. However, data on these parameters are sparse and uncertain for many species and unavailable for others, potentially leading to their misclassification or classification as data deficient.

Data from the CYGNSS mission, originally conceived to monitor tropical cyclones, are being investigated here for land applications as well. In this paper, a methodology for soil moisture (SM) retrieval from CYGNSS data is presented. The approach derives Level 3 gridded daily SM estimations, over the latitudinal band covered by CYGNSS, at a resolution of 36 km × 36 km, using the CYGNSS reflectivity over land, coupled with ancillary vegetation and roughness information from the SMAP mission.

The monitoring of waste disposal sites is important in order to minimize leakages of biogas, produced by anaerobic digestion and potentially explosive and detrimental to the environment. In this research, UAV-based thermal imaging has been proposed as a diagnostic tool to monitor urban landfills. Since the anaerobic decomposition produces heat along with biogas, thermal anomalies recorded over the soil are likely to be associated with local biogas escaping from the landfill terrain and leaving a local thermal print.

In this contribution, we analyze the bistatic scattering generated by agricultural soils, which can be characterized by a strong anisotropic component of the rough surface profile. A novel spectral representation is proposed in conjunction with a numerical solution of the scattering based on the well-known small-slope approximation. Comparisons are given with different modeling. The investigation provides interesting and novel information on the phenomenology of the bistatic scattering from the anisotropic soil.

The capabilities of bistatic radar observations to estimate the wind field over the ocean are investigated in this paper. The work is based on the analysis of simulated data obtained through a well-established electromagnetic model, which accounts for the anisotropy of the ocean's spectrum and of second-order effects of the scattering phenomenon. Both co-polarized and cross-polarized C-band numerical data, obtained considering monostatic and bistatic configurations, are exploited to investigate on the existence of optimal configurations able to minimize the wind vector error estimation.

The electromagnetic scattering generated by agricultural tilled soils can be affected by a strong anisotropic component of the rough-surface profile. An accurate and reliable modeling of the normalized radar cross section, under both monostatic and bistatic geometries, is particularly important and desirable, especially for the correct estimation of the soil moisture content by means of satellite-based observations.

The design of a K-band radial leaky-wave antenna is presented for polarization diversity applications. The antenna structure is constituted by an annular, radially periodic, and metallic strip grating printed on top of a single-layer grounded dielectric slab. The integrated feeding system is defined by a 2 × 2 array of planar slot sources for cylindrical surface-wave excitation.

We present and discuss an electromagnetic model for the description of the coherent scattering from bare soils illuminated by a radar system under arbitrary bistatic geometries. The scattering problem is solved under the Kirchhoff approximation (KA) accounting for both the sphericity of the wavefront of the incident wave and the radiation pattern of the transmitting and receiving antennas. We propose here a general formulation and solution of the scattering problem applicable to an arbitrary bistatic geometry.

Algal blooms of the water are an important variable for the analysis of freshwater ecosystems, which are relevant not only for human populations but also for plant and animal diversity. Monitoring algal blooms from space allows for a continuous and automatic control without the necessity of water sampling and human intervention. However, it is a very challenging task, which becomes particularly difficult when dealing with cyanobacteria blooms.

Millimetre-wave radiometers will be on board of the future operational Eumetsat Polar System Second Generation (EPS-SG) satellites with the primary objective to support weather and climate models. These radiometers, and in particular the Ice Cloud Imager (ICI), will provide channels from 183 up to 664 GHz at a spatial sampling of 16 km, greatly enhancing ice cloud retrieval capability at global scale to validate and improve microphysics parameterization.