This paper presents the findings related to the design solution options for a next-generation C-band Synthetic Aperture Radar (SAR) mission, developed to address the Harmonized User Needs (HUN) in Earth observation (EO) data as defined by several departments of the Government of Canada. The work analyses various mission solution options, including multi-satellite constellations, and their performance to evaluate feasibility and assess their compliance with the HUN as well as minimize the associated lifecycle costs, technical risks, implementation schedule, and programmatic challenges. This mission concept contributes to the advancement of space-based surveillance solutions aligned with Canada’s long-term strategic objectives to ensure service continuity for Earth Observation and national security applications. Systematic user needs analysis helped to reveal the importance of high-resolution (1–5 m), enhanced interferometric, polarimetric SAR interferometry (PolInSAR) and other capabilities. Two satellite constellation configurations are proposed: (1) a three-medium-satellite setup with a tandem pair, and (2) a five-large-satellite system incorporating tandem and optimal orbits. Employing High-Resolution Wide Swath (HRWS) imaging modes and full polarimetric capability. Performance simulations indicate low Noise Equivalent Sigma Zero (NESZ) with wide swath width fully addresses driving needs for sea ice and ocean monitoring, covering most of the Canadian areas of interest, with the revisit time of less than 4–6 hours. Orbit optimization ensures high revisit rates, enabling novel interferometric SAR (InSAR) capabilities with observations separated by only a few hours. This mission concept, considering two options with three medium and with five large satellites, respectively, offers a flexible, scalable, and strategically impactful solution for Earth Observation (EO) service continuity and technological leadership for Canada until 2050 and beyond.

In 2015, the International Telecommunication Union (ITU) World Radio Conference (WRC) extended the bandwidth available for civil X-band Synthetic Aperture Radar (SAR) satellites from 600 MHz to 1200 MHz. The objective of such extension was to achieve widespread socio–economic benefits enabling very high-resolution imaging, comparable to electro-optical sensors from space. Airbus and DLR played a significant role in achieving such a result, conducting significant technical studies to justify the utilisation of a higher bandwidth and making sure to establish limitations to protect incumbent services, such as radio-astronomy. On November 2, 2015 WRC-15, decided to extend the frequency band allowed for conducting active Earth Exploration Satellite Services (EESS(Active)), from 9 300 - 9 900 MHz to 9 200 - 10 400 MHz Such identification enables in principle to achieve an imagery resolution as fine as 12.5 cm. [1, 2] However, at WRC-19 International Mobile Telecommunication (IMT) spectrum demands targeted the 10.0-10.5 GHz frequency range. The objective was to identify such a range for terrestrial mobile networks (i.e., 5G) demonstrating incumbent services in band and adjacent (respectively, Earth exploration-satellite service (EESS)(Active) and EESS(Passive)) would not be affected. Official technical studies have been conducted between 2020 and 2023 to verify the possibility of coexistence between the 5G emissions and the SAR receivers. Such studies have shown that 5G deployment would cause significant impact on the performances of spaceborne or aeronautical SAR in all baseline scenarios. This paper examines the importance of protecting the 10-GHz frequency band for SAR applications, highlighting the challenges, the actual effects of 5G into SAR imagery and exploring the solutions to ensure SAR protection for continuing providing reliable and effective benefits for humanity.

TerraSAR-X radar technology is credited to be the most accurate radar sensor being utilized for innovative applications [1][2]. Extending this success, this paper presents a soon to be launched constellation of TerraSAR-X like X band SAR sensors. The injection of the PAZ satellite (owned and operated by Hisdesat S.A. of Spain) in Q4 2015 into the TerraSAR-X and TanDEM-X orbit will bring a unique radar constellation to the market. The benefits of this planned constellation mission shall be enormous leading to as short as possible revisit times with a promise of excellent quality and reliability. The constellation shall offer products ranging from very high resolution data for IMINT community to large wide swath scans for maritime services industry. On-top of the traditional constellation benefits, this program also demonstrates a novel approach to coordinate international space missions for all stakeholder benefits. In this paper we intend to present the following aspects of the constellation: Constellation Concept of Operations (CONOPS); Capability of the 25cm Staring SpotLight Mode in Comparison to traditional 1m radar imagery; The Unique Airbus DS access solution to access the constellation.

The last two decades have seen an unprecedented development in the satellite-based Earth observation industry. The combination of an increasing number of operational satellites, the higher resolution of the acquired data and the advances in the processing techniques have enabled a wider adoption of satellite data and the development of a diverse range of products and applications. Although the market is still strongly biased toward electro-optically derived imagery a rising tide of acceptance and usage of satellite derived Synthetic Aperture Radar (SAR) data can be noticed over the last few years. This trend is a result of the increasing availability of commercial SAR satellite data, development of sophisticated processing and analysis tools and industry driven training effort conducted to familiarize image analysts with the specifics of SAR imagery, its interpretation and its utility.

Since early 2007 the TerraSAR-X Mission provides X-Band data and services on an operational basis. Recent improvements and evolutions of the program comprise the introduction of new SAR imaging modes and the upcoming constellation with the Spanish PAZ satellite. The next major milestone in the German X-Band SAR roadmap will be the TerraSAR-X Next Generation (TerraSAR-X NG) Mission. The Mission is designed to guarantee the TerraSAR-X data and service continuity for commercial and public users beyond the year 2025 taking benefit of a 9.5 years satellite lifetime [1]. The TerraSAR-X NG Mission and potential extensions will be subject to a partnership model, WorldSAR, in which partners can participate through co-investment, subscription, and ownership of additional satellites operated in constellation.

The TerraSAR-X Next Generation (TerraSAR-X NG) mission is intended to take the TerraSAR-X data and service continuity well beyond 2025 taking benefit of a 9.5 years satellite lifetime [1]. The Space Segment, initially a single spacecraft, will be launched into the TerraSAR-X reference orbit while first generation TerraSAR-X systems will still be operational. The TerraSAR-X NG Mission will benefit from an advanced SAR sensor technology allowing a spatial resolution down to 0.25 meter depending on allowable chirp bandwidth in the future. Besides advanced Very High Resolution Modes TerraSAR-X NG will provide heritage modes enabling TerraSAR-X data continuity and improved wide swath modes to support large area applications. In addition the TerraSAR-X NG Mission will feature full polarimetry and improved near real time capabilities. The TerraSAR-X NG Mission and potential extensions will be subject to a partnership model, “WorldSAR”, in which partners can participate through co-investment, subscription, and ownership of additional satellites operated in constellation.

The TerraSAR-X2 Mission is intended to insure the TerraSAR-X service continuity from 2016 onwards and to provide new very high resolution products with improved performance parameters to the user community. The TerraSAR-X2 Mission will benefit from an advanced SAR sensor technology allowing a spatial resolution down to 0.25 meter depending on selected and allowable chirp bandwidth in the future. Besides the advanced Very High Resolution Modes the TerraSAR-X2 satellite will provide heritage modes that allow direct continuity of TerraSAR-X data and improved wide swath modes to support large area applications. In addition the TerraSAR-X2 Mission will feature full polarimetry and improved near real time capabilities. The TerraSAR-X2 Mission and potential extensions will be subject to a partnership model, “WorldSAR”, in which partners can participate through co-investment, subscription, and up to ownership of additional satellites operated in constellation. Service continuity through TerraSAR-X2 is intended to be ensured from 2016 until 2025, taking benefit of a 9.5 years satellite lifetime.