COSMO Second Generation

State of art technologies and system innovations for Earth Observation servicing excellence

Enrico Zampolini Faustini / Matteo Piemontese

1° Workshop nazionale : “La missione COSMO-SkyMed: stato dell’arte, Applicazioni e Prospettive future

ASI (Roma) 13-15 November 2017 COSMO Second Generation (CSG): a strategic national asset (1 of 2)

The CSG program pursues the national strategic objectives of : Ensure continuity of the SAR Earth Observation servicing from 2019 onward, while providing a significant improvement of performances Even though the COSMO-SkyMed (CSK) constellation (first generation) is still in operations, it should be pointed out that the first CSK satellite (FM-1) has already passed the 10 years of flight operations, whilst the other CSK satellites will soon reach this post: FM-2 this year, FM-3 in 2018 , and FM-4 in 2020 . The CSK satellite lifetime requirement is 5 years, thus augmenting the risk of a sudden occurrence of unrecoverable failures or of a significant degradation of performances, with necessity of deorbiting one or more CSK satellites

Consolidate and enlarge the Italian leadership on SAR observation from space, today recognized worldwide thanks to COSMO-SkyMed in a context of international competition, several Countries at largest economy are making big investments in future space radar systems for Earth Observation, e.g.: for EOSAT and SARah systems (follow-on of TerraSAR-X e SARLupe system, respectively), Canada (i.e. RadarSAT-3), South Korea (i.e. KoreaSAT-6), etc.

- 2 - 15/11/2017 COSMO Second Generation (CSG): a strategic national asset (2 of 2)

(Consolidate and enlarge the Italian leadership on SAR … contd.) Nowadays, emerging countries (e.g. Turkey, Argentina, , Turkmenistan, Finland … ) are showing more and more interest in SAR observation domain, envisaging themselves in different roles, either in promoting partnerships for using third party’s SAR systems (already existing and/or nearly coming ones), or becoming owner of a national proprietary SAR satellite system . Thus the Italian leadership on SAR space systems allows to keep a strategic prevalence on an increasing market of high technology. It will also preserve and enlarge business opportunities for Italian Industries, not only for those devoted to space, but also for a large variety of national companies, also including Small- Medium Enterprises (PMI) aimed at keeping and growing the high technology know-how in micro-electronics, chemistry, science of materials, fine mechanics, robotics, software and simulations, system engineering etc. Accomplish the international agreements undertaken by for constituting international partnerships of strategic interest … in Earth Observation domain, such as the international partnerships for CSG (e.g. Poland, Finland ..); the MUSIS-CIL cooperation program subscribed by Italian and French Defenses, of which CSG is the space radar component of federated constellations for SAR and electro-optical observation of the Earth from space, aimed at producing and exploiting multi-sensor imaging data for Defense use. - 3 - 15/11/2017 Toward the COSMO Second Generation (CSG) system in operations

Launch of Launch of CSG PFM satellite CSG FM-2 satellite with SOYUZ with VEGA (from Kourou ) (from Kourou ) End of Final in-flight Mission Critical Commissioning System Design Review with CSG PFM Acceptance Kick Off (M-CDR)

st Start of CSG Detailed Launch 1 st 1 satellite Launch 2nd 2nd satellite development Design and COSMO 2G in operations COSMO 2G in operations program C-D-E1 qualification phases Detailed Design models System Production and Commissioning and phase qualification phase pre-operative phase 2013 2014 2015 2016 2017 2018 2019 2020

COSMO Second Generation configured with the first two satellites

- 4 - 15/11/2017 COSMO Second Generation: key features compared to CSK

Orbit Sun synchronous @ 619Km Repeat Cycle 16 days Accessibility +/- 90° latitude Access Area 20° - 60° Daily Imaging capability per 520 standard images (dual pol) satellite (CSK 450 single pol)

Onboard Data Storage 1400 Gbit (CSK = 320 Gbit) 520 Mbps Downlink data rate (CSK = 310 Mbps) 2240 Kg Satellite Mass (CSK = 1860 Kg) Peak power consumption 20 KW during acquisitions (CSK = 12 KW) Projected satellite life time 7 years at full performance (CSK = 5 years)

- 5 - 15/11/2017 Summary of CSG main improvements and innovations w.r.t. CSK SPACE SEGMENT INNOVATIVE ELEMENTS capable to enhance: imaging performance (e.g. UHR) and quality, new imaging products characteristics and new SAR acquisition modes related to innovations performed on SAR sensor central electronics and SAR antenna satellite platform performances (e.g. more agility in attitude maneuvering, powered data handling and transmission data rate) operative profiles (acquisitions per day) and dynamic management of on-board resources satellite dependability on prolonged lifetime duration

IMPROVED SYSTEM SERVICING: new architecture and innovative design solution of CSG elements (ground centers, system tools, operative elements) will greatly improve servicing efficiency and reliability, especially for civilian use, without degrading the efficiency of governmental access to services at high priority, through: A brand-new Mission Planning System based on a priority-based algorithm capable to plan with great efficiency User’s acquisition requests ranked at several priority levels a high level of automation in CSG system architecture and operations support tools will contribute to reduce the system operative and maintenance costs during lifetime An efficient schema of CSG on-demand services (e.g. Very Urgent service, Last Minute Planning, requests subscription, on-demand area coverage) and CSG pre-programmed monitoring (Reserved Orbital Segment) as well - 6 - 15/11/2017 The SAR standard imaging modes: the CSG improvements compared to CSK New diversified modes and larger performances

(**) all values are in azimuth and range Ultra-High Resolution Very High Resolution (UHR) Resolution in range is worst case at lower incidence angle VHR (sub-metric) Governmental use Governmental use Several Sp-2 modes all VHR and Dual Pol. (**) Sp-2A res. ≤ 0.35 x 0.55 m Swath ≥ 3.1 x 7.3 Km Sp-2B res. ≤ 0.63 x 0.63 m Swath ≥ 10 x 10 Km Sp-2C res. ≤ 0.80 x 0.80 m Swath ≥ 5 x 10 Km Civilian and Defense use

- 7 - 15/11/2017 Key elements for CSG innovations: the SAR active antenna (1 of 2)

The SAR Antenna Subsystem (SAS) is one of the CSG elements that compound the majority of technology and design innovations characterizing the CSG mission

SAR antenna characterizing Parameter COSMO Second Generation (CSG) COSMO-SkyMed (CSK) SAR antenna sizes (m2) 5,7 x 1,4 5,7 x 1,4 Mass (Kg) 810 Kg 600 Kg Absorbed power (KW) 17 kW 11 kW RRF peak power (KW) 9 kW 5 kW Operative bandwidth (% of increasing) 300% * CSK reference CSK reference Double or quadruple simultaneous Polarization Single selectable polarization SAR antenna electronic structure 10 Macro-tiles 40 Tiles Number of T/R modules 2560 1280 Chip HPA in pHEMT (pseudo-morphic High Chip HPA in BJT (Bipolar Electron Mobility Transistor) Junction Transistor) Basic Technologies for T/R modules Core chip in Enhanced Depletion Mode --

Number of power suppliers 40 80 Number of digital controllers 10 40 RF calibration Active through core chip Trough passive path Spatial Resolution (NIRSS grade) of imaging UHR VHR modes for governmental use

- 8 - 15/11/2017 CSG improvements due to SAR sensor innovations Multiple polarization of CSG SAR modes: improvements w.r.t. CSK

CSK normally operates in Single Mode Polarization. In addition, CSK supports the "Ping-Pong" (PP), burst mode which is a capable to acquire the same CSK Single-Pol (HH case) scene with two polarizations (cross- or co- polarized). This approach creates a reduction of resolution (i.e. for PP mode is 15 m against the 3 m of the CSK Ping-Pong (HH, HV cases) Stripmap mode) as well as a partial incoherence due to the fact that the same target is viewed at different times  impact interferometric analysis Thanks to SAR antenna innovations, CSG introduces the Dual-Pol and Quad- Pol capabilities: CSG Dual Pol can simultaneously acquire two polarities, being extensible in all SAR operating modes (not only burst modes) with no degradation in performances (e.g. resolution, swath) and coherence. CSG Dual-Pol (HH, HV case) CSG Quad Pol makes use of pairs of Dual Pol interleaved acquisitions at double PRF. In this way, the resolution does not degrade, whilst the swath of CSG quad-pol becomes 15 km vs. 40 km of the Stripmap mode. In addition, the CSG quad-pol mode ensures the full coherence. CSG Quad-Pol (HH, HV, VH, VV cases) - 9 - 15/11/2017 CSG improvements due to SAR sensor innovations The CSG “non-standard” mode (DI2S Multi-Swath Spot-Spot acquisition)

Thanks to CSG innovations, in particular to the new design of the SAR antenna that enhances the “electronic agility” in image acquisition, CSG will provide a new “non standard” SAR mode, that is the Discrete Stepped Swath (DI2S) Multi-Swath Spot-Spot mode capable to simultaneously acquire a couple of Spotlight images on two distinct swaths. The DI2S MS mode can: rise the number of acquirable images on a given area that, otherwise, could not be taken through standard modes because of time gap violation Acquire two Spotlight images with: same azimuth position images shifted in azimuth same range and shifted in azimuth

- 10 - 15/11/2017 CSG improvements due to satellite platform innovations CSG Avionics devices for high agility: the Control Moment Gyro (CMG) (1 of 2)

The CSG satellite carries on a new generation of platform avionic devices that will significantly increase the satellite agility. This new actuator takes advantage of the gyroscopic effect produced by a rotor and a "gimbal“, designated as Control Moment Gyro Assembly (CMGA), consisting of three drive Actuator Units (CMG AU), two operative and the third in cold redundancy, all governed by the Control Unit (CMG CU).

The CMG spin rotor gimbals about an axis fixed in the spacecraft body, applying a torque to the spacecraft by changing the direction of the rotor’s angular momentum, not its magnitude. As such, the CMG acts differently from a reaction wheel (RW), which applies a torque to the satellite by accelerating the rotor (i.e. applying an angular momentum  magnitude variation). Thus, with respect to a RWs, the CMG devices are more efficient in terms of produced torque, whose value can be compared to that obtained using thrusters, without introducing the typical thruster disadvantages like thrust value predictability, reproducibility and low resolution for precise satellite attitude maneuvers- Indeed CMG allows to produce a continuous high torque along with a very good accuracy. Through the combined actions of one or more CMG, it will be possible to rotate the satellite of a specific angle, stabilize the orientation to snap a picture and continue like this until the interested zone has been passed over

- 11 - 15/11/2017 CSG application improvements due to high agility avionics devices Right-to- left looking fast slew and theatre scenarios

CSG will implement key applications improvements due to Control Moment Gyro (CMG) devices for high agility satellite platform: (1) Reduction of the transition time to pass from right to left looking and vice versa, hence shortening the access time to targets successively placed along the satellite flight path, (2) Keeping the satellite pointing to a target area during a flyby by rapidly moving the platform in the pitch-roll plane.

Right-left looking

- 12 - 15/11/2017 CSG application improvements due to high agility avionics devices A new SAR “non-standard” mode: Spotlight acquisitions on Theatre Scenario

More acquisitions in a given target scene (“theatre”): The CSG system, by exhibiting a very high satellite agility performance in attitude maneuvering, will be able to perform squinted SAR acquisitions keeping the pointing to a target area during a flyby by rapidly moving the platform in pitch-roll plane.

This allows the CSG system to serve more requests in a defined area; otherwise not feasible to be served because in conflict for time gap violation.

The Theatre Scenario definition will be a dynamic process built step-by- step according to User’s acquisition requests

- 13 - 15/11/2017 Conclusions

The evolution of COSMO Second Generation is deeply rooted into the experience gained in COSMO-SkyMed, because of:

The CSK solutions are still cutting-edge, in terms of reliability, imaging performances and quality obtained in dual (Defense and Civilian) use

More than 10 years of operative servicing constitutes a great return of experiences and lesson learned that have been capitalised in defining the new CSG system architecture and operative concepts aimed at greatly improving efficiency and reliability of the on-demand services that will be provided to a large variety of users, in a complex context as a dual-use priority-based system, as COSMO system actually is;

The technologies (on both space and ground segments) necessary for building up the CSG dual-use features today and in the coming future are mastered on the basis of the industrial know-how and a consolidated expertise operations-proven

The technology expertise is complemented by flight-proven operative practices of dual-use system that, together, constitute the consolidated know how and heritage of CSK

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