COMBINED USE OF SPACE-BORNE OBSERVATIONS OF NO2 AND REGIONAL CTM MODEL FOR AIR QUALITY MONITORING IN NORTHERN ITALY

The use of space-borne measurements of trace gas constituents for air quality monitoring is considerably increased during the past decade. This is due mainly to the new generation sensors able to observe large areas with good temporal resolution and due to new assimilation techniques that allow a synergetic use of information from satellite and from Chemical Transport Models (CTM). In fact the in situ sampling method used by the local environmental agencies for air quality monitoring is becoming too expensive to be further continued without a sensible reduction in the number of observing stations. In this paper we present the work that has been performed so far within the QUITSAT project funded by the Italian Space Agency. SCIAMACHY (Uv-Vis spectrometer on board ESA-ENVISAT platform from 2002) observations of earth radiance are used to retrieve NO2 tropospheric column by DOAS spectrometric technique and radiative transfer modelling for AMF computation. Such kind of product has been widely used to estimate emissions, to monitor pollution hot spot as well as cross country and intercontinental transport. Within this work we have merged the column measurements of nitrogen dioxide with the simulations of the Transport Chemical Aerosol Model (TCAM) to improve the model output at the ground level. The method used is a weighted rescaling of the model column in the troposphere according to the SCIAMACHY observations where the weights are the measurement errors and the model column variances within the satellite ground-pixel, respectively. The employed data are related to the Northern Italy area. The obtained ground concentrations of NO2 have been compared with in-situ observations performed by the regional environmental agencies. Results show good agreement mainly where well horizontal mixing is present. The ground concentration from SCIAMACHY-TCAM gives an average NO2 amount within the satellite ground-pixel of 30x60 km2 that is important information for air quality assessment on a regional and/or national scale not easy to obtain only with ground-based observations. Our conclusions thus stress also the actual potential role of satellite observations combined with regional CTM models in the context of air quality monitoring, mainly in rural area, where the ground-based observations are missing

A multi-input UV-VIS airborne GASCOD/A4r spectroradiometer for the validation of satellite remote sensing measurements

The present paper describes a UV-VIS spectroradiometer named GASCOD/A4r developed at ISAC-CNR for remote sensing measurements aboard stratospheric M55-Geophysica aircraft, flying up to 21 km. Obtained experimental data are used for retrieving of NO2, O3 and of other minor gases atmospheric content, applying the DOAS (Differential Optical Absorption Spectroscopy) method. UV actinic flux and J(NO2) are also derived. All these parameters are used for satellite data validation tasks. The specific results obtained during dedicated aircraft missions in different geographical areas have already been utilized for ENVISAT validation

Perspectives of 2D and 3D mapping of atmospheric pollutants over urban areas by means of airborne DOAS spectrometers

tants, offering numerous advantages over conventional networks of in situ analysers. We propose some innovative solutions in the field of DOAS (Differential Optical Absorption Spectroscopy) remote systems, utilizing diffuse solar light as the radiation source. We examine the numerous potentialities of minor gas slant column calculations, applying the «off-axis» methodology for collecting the diffuse solar radiation. One of these particular approaches, using measurements along horizontal paths, has already been tested with the spectrometer installed on board the Geophysica aircraft during stratospheric flights up to altitudes of 20 km. The theoretical basis of these new measurement techniques using DOAS remote sensing systems are delineated to assess whether low altitude flights can provide 2D and 3D pollution tomography over metropolitan areas. The 2D or 3D trace gas total column mapping could be used to investigate: i) transport and dispersion phenomena of air pollution, ii) photochemical process rates, iii) gas plume tomography, iv) minor gas vertical profiles into the Planetary Boundary Layer and v) minor gas flux divergence over a large area

VALIDATION OF SCIAMACHY NO 2 VERTICAL COLUMN DENSITIES WITH MT.CIMONE AND STARA ZAGORA GROUND-BASED ZENITH SKY DOAS OBSERVATIONS

ABSTRACT Ground-based zenith sky Differential Optical Absorption Spectroscopy (DOAS) measurements performed by means of GASCOD instruments at Mt. Cimone (44N 11E), Italy and Stara Zagora (42N, 25E), Bulgaria are used for validation of SCIAMACHY NO 2 vertical column density (vcd) of ESA SCI_NL product retrieved with 5.01 processor version. The results presented in this work regard satellite data for the JulyDecember 2002 period. On this base it is concluded that during summer-autumn period the overall NO 2 vcd above both stations is fairly well reproduced by the SCIAMACHY data, while towards the winter period they deviate from the seasonal behaviour of NO 2 vcd derived at both stations

Unmanned autogyro for mars exploration: A preliminary study

Starting from the Martian environment, we examine all the necessary requirements for a UAV and outline the architecture of a gyroplane optimized for scientific research and support for (future) Mars explorers, highlighting its advantages and criticalities. After a careful trade-off between different vehicles suitable for a typical mission, some parameters are established to optimize the size and performance. In the second part, the project of the Spider gyroplane and the methodolog used to balance the longitudinal masses are presented; in the third part, the parameters of the aerodynamic forces acting on the aircraft are highlighted to be able to focus them during the fluid dynamics simulations

Power Management and Reliability Analysis of Albacore: an AUV for Shallow Waters

In this paper we will examine in detail the development of the drone passing through different phases: first of all we will see its need for energy and how we can apply it through different types of batteries which therefore exploit different technologies. Secondly, we will examine the reliability of the drone itself from the point of view of the most vulnerable parts or the electronic components. This is to further advance the drone project

Beamriding Homing Systems for UAV: New Approaches and Applications

Our study stems from two specific requirements, namely to mount a homing system on the Unmanned Aerial Vehicle (UAV) that is light but at the same time very precise. This question is solved by moving the entire control infrastructure to the ground thanks to very small and low-power high-frequency transmission systems. As an additional advantage, we have that of unloading the vehicle from all the avionics specifically dedicated to homing. Our study concerns the revision and updating of beamriding systems based on radio interferometry

Unmanned autogyro for advanced SAR tasks: A preliminary assessment

This paper exposes the preliminary study for the development of an autogyro drone (UAV) which has search and rescue (SAR) tasks. We will illustrate the reasons for choosing the vehicle / autogyro first and then its peculiar architecture

Navigation equations, uncertainty and error budget in inertial navigation systems

INS systems are increasingly present on all vehicles and increasingly miniaturized. In this paper, we will examine the error budget of an inertial system through simplified navigation equations and how the error evolves over time. This is to highlight the need for external correction methods

The Geodesic Base of Piombino: The Measurement of Italy under an Historical Point of View

The cartographic unification of the Italian peninsula with the Carta Topografica d’Italia used the important work done during the pre-unification period and the last years of the XIX century. After the territorial unity of 1870 (leaving aside the appendix of the unredeemed lands of the north-east annexed after the Great War), the vision of a wider space for movement and citizenship took shape. For this reason, it is important to guard the memory and safeguard of all trigonometric points, like geodetic base lines, witnessing in the country the long and hard measurement work