The G4S 2.0 project represents an important opportunity to perform fundamental physics measurements with the two Galileo-FOC satellites DORESA and MILENA in elliptic orbits. In this paper, we discuss the possibility to improve the current constraints on local position invariance via a new measurement of the gravitational redshift, taking into account both a new model of the satellites and more in-depth considerations on non-gravitational perturbations.

BepiColombo, the forthcoming ESA (cornerstone) mission to Mercury, will include a comprehensive set of experiments - called Radio Science Experiments (RSE) in order to measure the gravitational field and rotational state of the planet and its rotation and to perform precise tests of Einstein's theory of general relativity versus other metric theories of gravity. Among the onboard instruments, a fundamental role in the RSE will be played by ISA (Italian Spring Accelerometer). This paper is devoted to the description of the main on-ground ISA internal actuators calibration and the obtained accuracy which is necessary to guarantee the accelerometer performance in order to reach the very ambitious objectives of RSE.

BepiColombo is a joint ESA/JAXA mission devoted to study the planet Mercury through two orbiters (MPO and MMO) to be launched in 2017. Among the main objectives, the European MPO aims at measuring the gravitational field of Mercury with unprecedented accuracy, through a careful reconstruction of the spacecraft orbit. The use of a very high sensitive tri-axial accelerometer, named ISA, will improve the orbital determination through an accurate sensing of the non-gravitational accelerations experienced by the spacecraft, mainly due to the solar radiation.The development of the three accelerometers, aluminium-made and constituted by electro-mechanical transducers, faced different issues to reach the required performance.One of the most relevant topic was the zero-g positioning, i.e. the measure of the sensing mass rest position when the sensor is in free-fall conditions (named briefly zero-g), condition that would be observed in orbit. The sensor offers the best performance when the sensing mass operates around this equilibrium position. Therefore this position needs to be identified and the mass has to be located there to guarantee the requirements imposed by the measurement of the non-gravitational accelerations. The group of Experimental Gravitation at IAPS/INAF in Rome developed an experimental procedure and a set-up to measure the zero-g position, carrying out a measurement campaign. This procedure will be applied to measure the zero-g positioning of ISA flight models. (C) 2016 Elsevier B.V. All rights reserved.

The key role of the Italian Spring Accelerometer (ISA) in the radio science measurements of the ESA BepiColombo mission to Mercury is to remove, a posteriori, the non-gravitational accelerations acting on the Mercury Planetary Orbiter (MPO) due to the very strong radiation environment around Mercury. This paper is devoted to describe the on-ground actuator calibration procedure along with the facility assembled to carry it out. Such a calibration is necessary to guarantee the accelerometer performance and hence to reach the very ambitious objectives of the Radio Science Experiment (RSE) of the ESA mission.

A cryogenic differential accelerometer has been developed to test the weak equivalence principle to a few parts in 10(15) within the framework of the general relativity accuracy test in an Einstein elevator experiment. The prototype sensor was designed to identify, address, and solve the major issues associated with various aspects of the experiment. This paper illustrates the measurements conducted on this prototype sensor to attain a high quality factor (Q ∼ 10(5)) at low frequencies (<20 Hz). Such a value is necessary for reducing the Brownian noise to match the target acceleration noise of 10(-14) g/√Hz, hence providing the desired experimental accuracy.

Nowadays, climate and meteorology assumed a fundamental role in manifold domains with the aim to understand how they affect life in modern society. Such a new sensitivity is the result of a major awareness of the Earth health and the need of better understanding the increasing climatic and meteorological changes recently observed. Actually, in the last years several satellite missions, single and cooperative, have been proposed and developed by NASA, ESA and JAXA. They aim at studying the overall atmosphere, its main elements and their close relations. On the other hand, in a different domain such as telecommunications, the low frequency bands crowding and the increase of broadband services diffusion has created the premises for the development of studies on the characterization and the development of telecommunications in the millimetric band not yet explored for this purpose (Q-V bands-35-75 GHz, W band-75-110 GHz). Actually, nowadays satellite telecommunications at Ka band can be considered a standard for broadband services. Higher frequencies such as Q-V bands are currently employed for military applications (SICRAL satellite of the Italian Defence Ministry) and soon for scientific applications (TDP#5 payload on-board the ESA Alphabus platform [1]). W band can be considered as the most important scientific frontier within the broadband satellite communications, since no satellite system operating at such a frequency has been developed, just studies such as DAVID and WAVE [2][3][4]. In the last years these fields registered a convergence of research activities towards the use of electromagnetic radiation at millimetre wavelengths, i.e. the EHF band (Extremely High Frequency, 30-300 GHz). In telecommunications the use of carriers at higher frequency implies theoretically the possibility of using wide bandwidth and hence greater data rate in down link. In the field of weather and climate satellite observations, the technology advancements of the last 10 years make available several sensors (radar, lidar, radiometers, etc.) in the 30-300 GHz band. They allow, by means of observations unpredictable some years ago, for broadening the knowledge of meteorological and climatological phenomena and the improvement of predictive models. However, the capability of collecting large data volumes leads to a related capability of transmitting the data to ground within reduced visibility windows. An integrated TeLeCommunication-Earth Observation approach (TLC-EO) could satisfy both needs. ARES (Advanced Research and Engineering for Space), a consortium constituted both by scientific institutions (the University of Rome Tor Vergata) and industrial partners (Rheinmetall Italy and TECS, TEchnological Consulting Services) carried out a feasibility study to investigate an innovative satellite devoted both to Earth remote sensing and to high frequency telecommunications. Both payloads are based on the common use of millimetric band to exploit the favourable characteristics of such high frequencies. The study is called PLATON (PayLoad for Advanced Telecommunication, Observation and Navigation) [5].

In the last years EHF (Extremely High Frequency / 30-300 GHz) band is acquiring more and more interest in different fields, such as telecommunications, radar applications and Earth observation, due to advantageous characteristics. Actually, the higher operating frequency with respect to traditional ranges (Ka and lower) allows the achievement of some advantages: no crowding in frequency and hence reduced interference, large bandwidth availability, reduced antenna and electronic components size, and more security in point-to-point links due to smaller beamwidth. Moreover, the increase of frequencies allows the realization of, with respect to lower bands, high resolution applications, as radar images and Earth Observation sensors. However, although W band is an attractive range, it is yet an experimental frontier since no telecommunication mission has been carried out and the technology development at this frequency is still poor, costly and relatively not ready. However, some specific applications, such as radar and radio-astronomy, and just for some frequencies (typically around 94-96 GHz), make an exception. Considering this context, a very significant and preliminary step to useful W band exploitation for terrestrial and satellite telecommunications is represented by the analysis and the validation of a terrestrial link operating at these frequencies with the capability of carrying out transmission/reception experiments. In this frame, the University of Rome, "Tor Vergata" in collaboration with the company Rheinmetall Italy is carrying out an experiment based on the establishment of a W band point-to-point terrestrial link over a distance of some kilometers between the University of Rome "Tor Vergata" (Rome) and Villa Mondragone (Frascati, near Rome). The work aims at showing an overview of the preliminary design of the experimental W band terrestrial air link. It will be very useful mainly for two reasons: firstly, in order to provide a test-bed for evaluating atmospheric effects (fading and scintillation, along with amplitude, phase, and polarization distortion) that could compromise the performance of satellite-to-ground communications systems operating at these frequencies; and secondly to verify performance of W band critical technology. The last part of the work investigates the possibility of using, in addition to the traditional approach, Impulse Radio Ultra Wide-Band (IR-UWB) technology for realizing very high bit-rate point-to-point Line Of Sight (LOS) last mile links beyond 60 GHz. This paper will firstly provide a preliminary orographic and propagation analysis of the terrestrial link. Then, a detailed insight into link architecture and transmitter/receiver schemes will be reported taking into account constraints related to the characteristic of the available HardWare (H/W) in Rheinmetall Italy. Finally, an accurate link budget for dimensioning the system in terms of maximum link capability will be reported.

The recently allocated 71-76 GHz and 81-86 GHz bands provide an opportunity for Line Of Sight (LOS) links for directional point-to-point “last mile” links. An efficient use of this spectrum may allow wireless to finally “catch up” with wires, leading to systems such as “multi-Gigabit wireless Ethernet,” and “wireless fiber.” However, the transmission at such a frequency range is characterized by several additional challenges compared to lower frequency bands, from the technological and propagation point of view, which makes difficult to use them efficiently. In this scenario, IR-UWB technology might offer some more degrees of freedom for the design of a highly integrated, low cost transceiver. This work has at its core the design and BER (Bit Error Rate) performance evaluation of an IR-UWB architecture based on an 85 GHz (this frequency belongs to W band/75-110 GHz) up-conversion stage of train of Gaussian pulses having a duration lower than 1 ns. Finally, we compare performance of this architecture with the ones of a more traditional continuous wave communications system with FSK (Frequency Shift Keying) modulation. Simulation results show that BER performance, in presence of RF non-linearities, for an IR-UWB transceiver architecture operating at W band (with same data rate and bandwidth) are better than a coherent BFSK scheme working in a similar scenario.

Advancements pursued in the last tenths of years in technology have been applied to medicine encouraging therapy and diagnostic procedures more and more sophisticated. The development of new biocompatible materials able to be integrated in human body needed to cure tissues and organs damaged is a very promising area of application to be investigated. However, information about biocompatible materials is at present widespread around the world, not standardized and fragmented. This paper presents a project aimed at solving those questions through the implementation of a World Biomaterial Bank based on an intelligent database.

Considering the convergence of research activities in the field of telecommunications and weather-climate observations toward the use of millimetre wavelengths, ARES (Advanced Research and Engineering for Space), a consortium constituted both by the University of Rome Tor Vergata and industrial partners (Rheinmetall Italy, TECS/TEchnological Consulting Services), has recently submitted a proposal for a feasibility study to investigate an innovative payload devoted both to Earth remote sensing and to high frequency telecommunications. Both the payload applications are based on the common use of millimetric band to capitalize on the favorable characteristics of such high frequencies. The study is called PLATONE (PayLoad ad Alta tecnologia per Telecomunicazioni ed Osservazione integrato con ricevitore software radio di NavigazionE, Italian acronym standing for the greek word PLATON, PayLoad for Advanced Telecommunication, Observation and Navigation). This paper aims at presenting the preliminary results of PLATONE study and its main objectives, outlining the main trade-offs that will be considered, waiting for the start of Phase A.

Since the 70s Italy has had a pioneering approach to higher frequencies, at first at Ka band (20/30 GHz) with the Sirio experience (launched in 1978), when such a range was still a frontier, and then with Italsat F1 and F2 experiments in the 90s [1], studying Q and V bands in addition to Ka one as well. After those experiences, Italy through the Italian Space Agency (ASI) was one of the first European countries that have made an effort toward the exploitation of Q/V band in telecommunications. In 2004 ASI funded a feasibility study (phase A), called TRANSPONDERS, Italian acronym for “research, analysis and study of Q/V payloads for telecommunications”, aimed at studying and designing a payload to be used to fully characterize the channel at Q/V bands and to test novel adaptive interference/fading mitigation techniques such as ACM (Adaptive Coding and Modulation). Finally, the feasibility and performance of preliminary broadband services in such frequencies can be verified through this study .A new phase has recently started (April 2008), called TRANSPONDERS-2 and leaded by Space Engineering S.p.A., to continue the achievements gained during the first phase. In this scenario, it is mandatory to identify pre-operative experimental missions aiming at fully verifying the feasibility of future Q/V bands satellite telecommunication applications. The experimental goals are mainly to test the effectiveness of Propagation Impairment Mitigation Techniques (PIMTs) [2] in such frequency bands and the minimization of implementation risks for operative system characterized by a series of technological challenges.

Since 2004, afterwards the US announcement, a renewed spirit of exploration has pushed space agencies in the world to promote new programs and studies devoted both to return to the Moon and to prepare a human mission toward Mars. Main objectives of this new phase of the space exploration is to collect as many as possible science data of the two planetary bodies and to acquire and test the technological basis on which to found the human challenge to the red planet. Within this context, Italy through the Italian Space Agency has recently funded a study for Moon remote sensing named MAGIA (Italian acronym standing for mission for lunar altimetry, gravimetry and geochemistry), and currently carried out by Rheinmetall Italy as prime contractor. The mission foresees the development of different payloads for Moon study, including an innovative radar-altimeter-radiometer (RAR) operating at millimeter wavelengths (95 GHz). This paper, after introducing the MAGIA mission, focuses on the preliminary activity, currently ongoing, of radar designing and dimensioning along with the trade-off carried out.

Ultra-WideBand (UWB) technology is very attractive since it offers a different approach to wireless communication compared to conventional narrow band systems. Global interest in this technology is high. This paper reports on the state of the art of UWB wireless technology and highlights key UWB features to apply UWB concepts in EHF frequencies, considering technological constraints and challenges on the realization of tx-rx architectures. In particular, the idea is to employ the UWB features exploiting the huge availability of bandwidth at high frequencies and overcoming the power emission limits, compliant with lower frequency communications (FCC standard) but not applied to W band. This could be a possible solution to increase transmission datarate and coverage ranges in order to support the new incoming communications needs. The analysis has been focused on W band UWB pulses generation and two different architectures have been analyzed and compared in terms of performance and complexity.

Broadband technologies are taking a predominant role in the emerging information society. In particular, broadband satellite communication systems, with their global access and broadcasting capabilities, are well suited to answer to the requirements of the information society. This paper focuses on the efforts that are currently spent toward the development of EHF (Extremely High Frequency) satellite communications systems. In particular, Q/V (35-75 GHz) and W (75-110 GHz) bands, represent an almost ldquofreerdquo spectrum resource that could be used to realize the so-called satellite gigabit-connectivity, in order to support innovative broadband applications. This paper presents the most important features of an experimental Q/V band satellite network based on the Alphasat TDP#5 (technology demonstration payload), an ongoing project, funded by the Italian space agency, that aims at carrying out communication and propagation experiments over a Q/V band satellite link.

The increasing needs of European observation and telecommunication satellite services, with respect to operations efficiency, require the development of an advanced in-orbit infrastructure for data relay services. The function of a data relay satellite is to forward data between two elements with which it has established a direct communication link. Currently the infrastructure is based on the ESA ARTEMIS satellite that has been operative since 2003 and that will be at end-of-life by the end of 2010. In this frame Thales Alenia Space Italia (TAS-I) and University of Rome "Tor Vergata" (TOR) are conceiving the new European Second Generation Data Relay Satellite System (E2GDRSS) based on state of the art and innovative space technologies and telecommunication techniques. This paper presents the main design options according to preliminary trade-off analysis, which will represent the baseline to the design of the full system.

Nowadays W band (75 - 110 GHz) is an experimental frontier since no satellite telecommunication mission has been developed and the technology at these frequencies is still poor and relatively not ready. In this framework, a preliminary useful step toward the W band exploitation in satellite telecommunications is represented by the analysis and the validation of a terrestrial link operating at these frequencies with the capability to carry out transmission/reception experiments. Such experiment could give important feedback from the technology point of view and also for the channel characterization. In this frame, the University of Rome Tor Vergata in collaboration with the company Rheinmetall Italy is carrying out an experiment to investigate a W band terrestrial point-to-point link over a distance of around 15 km. Many technological issues must be faced. In this paper, we present an overview of preliminary design of an experimental W band terrestrial air link identifying main critical elements.