Thanks to technical innovations the new SAR (Synthetic Aperture RADAR) systems can improve their performance. In particular, the well-known constraint relating SAR image resolution to swath has been analyzed in literature and several ways have been proposed and implemented to offer simultaneously high resolution and wide swath products. The paper will present the main techniques to overcome these constraints, such as space sharing, time sharing and angular sharing. Starting from these logics, new solution have been introduced in the CSG (COSMO-SkyMED di Seconda Generazione) system in terms of innovative techniques improving the portfolio of CSG system modes performance, size, flexibility and available information. CSG FM#3 and FM#4 will offer a new solution (Thales patent pending) thanks to the combined use of angular sharing and time sharing, called DIstributed Sparse Sampling for SAR Strip (DI4S). The key aspects of DI4S mode are described in this paper, as well as the main results already obtained with the non-standard acquisitions of the in orbit CSG PFM and FM#2 satellites.

COSMO-SkyMed Seconda Generazione represents the follow-on mission of COSMO-SkyMed currently operating with the full constellation in orbit, characterized by the capability to guarantee operational continuity and all improvements in terms of architectural enhancements at both Ground Segment and Integrated Logistic Support and Operations segment level. By exploiting the peculiar characteristics of flexibility and expandability of the CSK system, CSG will preserve and enhance the ability of Customers and Users to fulfill their mandates [1]. The key words of CSG mission are: CSK mission follow-on, continuity of service, performance improvement, operative versatility and interoperability with external systems.

COSMO Second Generation (CSG) system has been conceived, according to the requirements stated by ASI and I-MoD, at the twofold need of ensuring operational continuity to the currently operating “first generation” COSMO-SkyMed (CSK) spacecraft constellation, while achieving a generational step ahead in terms of functionality and performance. The improved quality of the imaging service is among the foremost characteristics of CSG (see [5]), providing the End Users with new/enhanced capabilities in terms of higher number of images and increased image quality (i.e. larger swath, and finer resolution) with respect to COSMO-SkyMed (first generation) spacecrafts currently in operation, along with additional capabilities (e.g. full polarimetric SAR acquisition mode). The greater operative versatility in system resources management is one of the key aspects of the design approach. Some examples are the satellite agility both at platform and antenna level, used to increase the density of acquisitions in a fixed region, the capability to adapt operative profiles to system environment (e.g. sun illumination, downlink scenarios), service request planning process not only function of the priority but also able to maximize the system resources exploitation.

COSMO-SkyMed is the most important Italian Earth Observation space program. The program is funded by the Italian Ministry of Research and Italian Ministry of Defence (I-MoD) and conducted by the Italian Space Agency (ASI) in conjunction with I-MoD. COSMO Second Generation (CSG) system has been conceived, according to the requirements stated by ASI and I-MoD, at the twofold need of ensuring operational continuity to the currently operating "first generation" COSMO-SkyMed (CSK) spacecraft constellation, while achieving a generational step ahead in terms of functionality and performances. In order to ensure such continuity, the new CSG satellites will be ready for operations timely to replace the previous generation satellites whenever they are being progressively phased out at the end of their lifetime.In the current days, after having defined the mission fundamentals of the CSG space borne imaging radar system, the detailed design of both space and ground segments elements has been undertaken. In this frame this paper delineates the key concepts of the CSG system in terms of service improvement and relation with CSK.The improved quality of the imaging service is among the foremost characteristics of CSG, providing the End Users with new/enhanced capabilities in terms of higher number of images and increased image quality (i.e. larger swath, and finer resolution) with respect to COSMO-SkyMed (first generation) spacecraft currently in operations, along with additional capabilities (e.g. full polarimetric SAR acquisition mode) and a greater operative versatility in programming and sharing the system resources among different typologies of Users that request images of different characteristics.Further, while describing the above mentioned topics, this paper shows the key aspects of the CSG engineering approach adopted in order to conceive CSG, that starting from the User requirements ends with the design of the lowest-level system building blocks. Besides, key elements both at space and ground segments are highlighted within this paper.

A primary scope of Mars exploration is the research of underground water. Knowledge of water and ice quantity and distribution has enourmous impacts on our understanding on gelogic, hydrologic and climate evolution of Mars and of its origin. To this aim, high resolution observations of geophysical parameters can address these items expecially when conducted by means of penetrating radar systems orbiting around the planet, due to their intrinsic capabilities to detect underground water/ice. In this framework, SHARAD (SHAllow RADar) on-board NASA’s Mars Reconnaissance Orbiter (MRO) assumes a key role within Mars exploration activities. SHARAD is a wideband radar sounder transmitting at a centre frequency of 20 MHz within 15-25 MHz spectral range. SHARAD has been launched on August ’05 and will start its nominal observation phase from November ’06. To guarantee its operations, commands and data analysis and processing, the SHARAD Ground Data System (GDS) has been designed and developped. SHARADA GDS is a ground system equipped with ad-hoc sw tools to allow instrument operations and data processing during the two-year mission duration. The present paper is focused on SHARAD GDS description of its architecture and of instrument planning, commanding and data processing sofwtare tools.

Mars' polar regions are covered with ice-rich layered deposits that potentially contain a record of climate variations. The sounding radar SHARAD on the Mars Reconnaissance Orbiter mapped detailed subsurface stratigraphy in the Promethei Lingula region of the south polar plateau, Planum Australe. Radar reflections interpreted as layers are correlated across adjacent orbits and are continuous for up to 150 kilometers along spacecraft orbital tracks. The reflectors are often separated into discrete reflector sequences, and strong echoes are seen as deep as 1 kilometer. In some cases, the sequences are dipping with respect to each other, suggesting an interdepositional period of erosion. In Australe Sulci, layers are exhumed, indicating recent erosion.