Airbus Defence and Space GmbH and Hisdesat Servicios Estrategicos S.A. partnered to create the WorldSAR Constellation, offering premium X-band radar imaging with the additional benefits from a true constellation made of satellites with identical performance. The Constellation is composed of the PAZ mission from Hisdesat and the TerraSAR mission (defined by TerraSAR-X and TanDEM-X satellites) from Airbus.

The WorldSAR Constellation, operational since the launch of PAZ in 2018, has been possible thanks to commercial corporate investments together with public anchor customers and Public-Private-Partnerships in Germany and Spain.

As the missions are fully compatible, the Constellation delivers SAR data and InSAR layer stacks with double revisit rate –even across mission- and improved operational reliability.

Since the launch, several new features have been added to the offer to meet the growing demands of the end-user community –including Copernicus- like new imaging modes for premium imagery performance and improved timeliness. With respect to the last point,
in collaboration with service providers around the globe, a network of partner antennas has been set up in order to improve the access to the Constellation. This network continues to grow, and today enables Near Real Time access within Europe and a range of selected areas around the globe.

As unique feature, the TanDEM mission has provided the CopDEM used by Copernicus today; in addition, for CCM new features are being made available to provide an impression for a CopDEM Evolution: access to a new global 5 m WorldDEM Neo (update based on new data takes) and Elevation 1 based on Pleaides-NEO.

Growth plans for the Constellation future will also be presented.

Planet is a Copernicus Contributing Mission (CCM) with its three optical constellations: SkySat (VHR1), PlanetScope (VHR2) and with the archive of the retired RapidEye constellation (HR1).
The mission of Planet is to image the entire Earth every day, and make global change visible, accessible, and actionable. This mission is realized thanks to the operation of the world’s largest fleet of Earth-imaging satellites, with approximately 200 satellites in operation and over 500 designed and built to date.
Planet was founded in 2010, with an agile approach to designing, building, and operating the satellites, as well as the new ways in which the datasets are offered to the end users.
The CCM on-demand portfolio offers the key Planet’s products that complement Copernicus users especially in Emergency, Security and Land services.
PlanetScope is the largest constellation imaging Earth every day, capturing over 3 million images each day with 3-4m Ground Sampling Distance (GSD). For the newest generation of PlanetScope satellites 6 of the 8 spectral bands are the same as those offered by Sentinel-2, which makes these datasets perfectly complementary for use cases, where Sentinel-2 spatial and/or temporal resolution is not sufficient alone.
Due to the fact that PlanetScope’s fresh imagery is available almost daily for the entire landmass of the Earth since 2017, it is a perfect dataset to monitor events in a continuous manner over a longer period of time and the dataset that will be always available before events take place. PlanetScope gives the possibility to analyze long-term and rapid changes in all phases of emergency and security events, including:
- For risk reduction, PlaneScope data supports mitigation of disaster risk exposure with recent and accurate modelling, informed preventative measures, and efficient deployment of resources.
- Coordinating responses, it helps to increase situational awareness.
- In recovery planning, the data enables informed decisions about quick estimation of the extent of damage and overseeing short-term and long-term recovery efforts, including construction, revegetation, and repair of critical infrastructure and systems.
Last but not least, the high frequency of PlanetScope data can be used by Copernicus Land Monitoring Services for detailed land use and land change detection, even on a near daily basis.
Planet’s CCM portfolio also offers VHR1 SkySat constellation capabilities. These satellites operate from inclined and sun-synchronous orbits and are able to provide image products with 50cm pixel size. This constellation is capable of rapid revisit and can capture 6-7 images of a particular location on earth per day. The constellation serves at equator crossing times in the morning and in the afternoon. The afternoon crossing passes offer additional acquisition windows to Copernicus users, which is especially beneficial in security and emergency use cases, where the observation of evolution of events is of high importance. Currently, Copernicus users can select the date and time window of the acquisition.
Combining both Planet types of data together offers the option to implement Tip & Cue systems, leveraging PlanetScope’s wide area monitoring capabilities and complimenting them with SkySat data which provides a more detailed view over selected areas.
As a relatively new and innovative CCM product, Planet also offers to all Copernicus users the Planet Data View Service, which enables streaming and previewing of all available Planet datasets, to discover and visually assess needed Areas of Interest (AOIs) on a global scale.
Planet follows an agile aerospace approach, which means that the PlanetScope and SkySat constellations and datasets are constantly being improved and created to complement the existing offer. It also means that the Copernicus users always have access to the newest data products.
Pelican, a next-generation fleet of satellites for VHR imagery, begins launching in 2022 and will be operational in 2023. When fully operational, the Pelican constellation replenishes and upgrades Planet’s existing high resolution SkySat fleet with better spatial resolution, more frequent image revisit times, and reduced reaction time and latency.
For the expected evolution of the Copernicus Contributing Missions, Planet offers not only new data types (i.a. SkySat Video, SkySat Stereo images, Basemaps, Planet Fusion Product) but also new data delivery models, such as data subscriptions to specific AOIs (“Area Under Management”) and data bundles to make use of the data economies of scale and New Space capabilities.

Airbus is facing one of its most important periods since a decade, shaping our future with a constellation of 6 VHR satellites with 2 Pleiades at 50cm and 2 Pleiades Neo at 30cm resolution (and 2 more to come). We are preparing this new era, upgrading all our systems with an important human and technological investment. . From tasking our satellites to the delivery of our products, we are improving all the steps deeply linked to the information system and our digital cloud-based platform One Atlas.
Following the successful launch of the first two Pléiades Neo satellites in 2021, Europe now has autonomous and sovereign very high resolution optical capabilities with 30cm resolution.
Beyond the fact that it’s 100% European, what makes Pléiades Neo so unique? It consists of 4 EO satellites, providing 30cm optical imagery, entirely funded and operated by Airbus Defence and Space. After more than 30 years of experience in satellite imagery services, it seemed like the logical way forward. In addition, Pléiades Neo is also the result of a whole new approach in terms of image quality and satellite capability. It has required rethinking the way we design satellites and exploit their services to answer a growing demand for increasingly large areas, complex requirements as well as last minute adaptations in tasking according to weather conditions and angles. All of that whilst ensuring best in class resolution with impeccable image quality.
Highestprecision with massive acquisition
Firstly Pléiades Neo provides 30cm native resolution meaning that the image shot by the satellite is the actual image you receive in terms of resolution. The image therefore provides an incredible amount of details that don’t appear on lesser resolution imagery, for instance: you can make clearly see road markings, traces in the sand, cables on construction sites, details of what is being loaded on docks, even people gatherings, distinct animals and people thanks to their shadows. The geolocation accuracy which measures the exact position of an object on an image, is 5m CE90.
And if one considers precision isn’t enough, in terms of acquisition capacity, the constellation is able to acquire up to 2 million square kilometers, every single day. Two million square kilometers at 30cm resolution fully dedicated to customers, every day.

Introducing intraday revisit
It is also the first time Airbus provides an intra-day revisit capability within the same constellation. Indeed depending on the incidence angle of the satellite and the latitude of the Area Of Interest (AOI), Pléiades Neo can provide between 2 and 4 revisits per day. More particularly the tests that have been conducted over several areas and shown a minimum of 2 revisits per day and a maximum of 3, providing over 28 days a total of 64 revisits. And that’s just with two of the four satellites fully operational today.
Ultimate reactivity tasking and image delivery
Work plans are updated every time a satellite enters into S-band contact, be it every 25 minutes (an orbit is 100min, 1h40), or 15 times per day per satellite. It represents around 60 plans uploaded every day at the constellation level.
Work plan are also pooled. This means that when an image is to be collected by one satellite, the related acquisition request is removed from the tasking plans of the other satellites.
These multiple and synchronised work plans per day enable easy handling of last-minute tasking requests – which can be placed up to 15min before S-band contact- as well as integration of the latest weather information, for an improved data collection success rate.
In addition, Airbus Defence and Space’s network of ground receiving stations, enabling an all-orbit contact and thus ensuring near real-time performances worldwide and rapid data-access, ensure the highest standards in terms of reactivity of our service.
Images are downlinked at each orbit, automatically processed and quickly delivered to the customer, allowing faster response when facing emergency situations.

New spectral bands
In terms of spectral bands, Pléiades Neo will acquire simultaneously the panchromatic channels and 6 multispectral bands, which are:
- Deep Blue
- Blue
- Green
- Red
- Red-Edge
- Near Infrared
Red-Edge and Deep-Blue are two additional bands, compared to its predecessor Pléiades, which unveil complementary information for respectively vegetation and bathymetry applications. In urban environments, deep blue provides details of what is reflected in the shadows of the skyscrapers, therefore enabling far richer applications in working on e.g. smart cities and the monitoring of construction sites. Red-Edge can further enhance our understanding of vegetation and bring the processing of biophysical parameters to a completely new level and support the most efficient and respectful use of our precious natural resources on the Planet.

Finally, the tasking of a VHR satellite orbiting 600 km above the earth has never been easier. OneAtlas, our digital platform, allows the users to draw their AOI, choose Pléiades Neo as optical sensor and choose the date of acquisition while accessing the whole Airbus imagery archive.

By providing more data, more detailed, more rapidly and in a more accessible way, Pléiades Neo becomes the best support for Copernicus Contributing Missions.

GEOSAT-2, formerly known as DEIMOS-2, provides 75-cm resolution products with best-in-class accurate and top quality VHR imagery. The multi-spectral capability includes 4 channels in visible and near infrared spectral range (red, green, blue, and NIR) with a radiometric resolution of 10 bits, having both mono, tessellation and stereo-pair imaging modes.

GEOSAT-2 has been providing support to both CORE and ADDITIONAL requests for Copernicus program as Contributing Mission since its launch in 2014, with the aim of providing the maximum flexibility for the successful fulfilment of the Copernicus services objectives. All services proposed by GEOSAT have proved to be flexible to ESA requirements updates during all these years, including the PAT scenario for enhanced reactiveness and data availability to emergency situations.

Being one of the two European VHR contributing missions, GEOSAT-2 has contributed to the latest 3 cloud-free VHR optical coverage of 39 European States (EEA-39) acquired within predefined windows corresponding to the vegetation season, i.e. VHR_IMAGE_2015, VHR_IMAGE_2018 and VHR_IMAGE_2021. Additionally, several GEOSAT-2 datasets have been provided following the ESA operational requirements for standard and emergency VHR imagery, including provision of metadata compliant with INSPIRE directive. Complemented by a 24/7 Customer Service Desk provision, together with the Data Privacy, Issue and Security management associated to data provision, GEOSAT-2 will continue to offer a great value to Copernicus services needs during the forecoming extension phases of the CSCDA contract.

The extensive portfolio offered by GEOSAT benefits worldwide customers and partners by providing reliable solutions that significantly accelerate decision-making in a great variety of fields, from Land to Marine, and specially focused on Emergency services for a quasi-real time service data provision on a worldwide scale. The combination of a enhanced super-resolution product (up to 40cm) with reliable and swift value-added products delivered in less than 30 minutes would provide a unique set of services available for Copernicus services.

European Space Imaging (EUSI) has been a Copernicus Contributing Mission Entity since GMES Data Warehouse Phase I in 2011. The company operates its own multi-mission ground station at the German Aerospace Centre (DLR) near Munich (Germany) that enables EUSI to directly task the Maxar WorldView constellation of currently 4 optical very high resolution (VHR) satellite sensors with a spatial resolution of 0.5 to 0.3m at Nadir, as the satellites pass over Europe. The direct tasking capabilities allow for last-minute order entry with short lead times, as well as the consideration of the real time weather situation shortly before the satellite pass to maximise the acquisition yield in terms of cloud-free imagery per satellite revisit. Additionally, EUSI can directly downlink the performed acquisitions for rapid production and dissemination to its customers as fast as 30 minutes.

In partnership with Maxar, EUSI offers eligible Copernicus users access to worldwide tasking of the WorldView constellation and a global VHR satellite imagery archive of more than 125 petabytes, dating back as far as 1999. Both offerings are made on a 24/7 basis through a dedicated emergency ordering desk. Additionally, tasking and archive data requests from Copernicus users are managed at highest priority to ensure fast response and order turnaround times. Thanks to these premium services and space assets, European Space Imaging and Maxar have developed to a major provider of optical VHR remote sensing data with a resolution of 0.5m and better to the Copernicus programme over the past years, notably to the Copernicus core services for Security, Emergency Management and Land Monitoring.

The presentation will provide an overview of European Space Imaging’s VHR imaging capabilities as well as an outline of the company’s contribution to the Copernicus program so far, in particular major milestones and achievements with regards to service and earth observation (EO) data provision. Furthermore, EUSI’s ongoing contribution to the evolution of the CCM activity will be addressed. On the one hand, this evolution consists of the introduction of new EO data ordering and delivery interfaces, like a REST API and the adoption of the OGC Sensor Planning Service (SPS) protocol to further standardize and automate the EO data request management process. On the other hand, with the upcoming Maxar WorldView Legion satellite constellation new VHR imaging assets will be launched and also made available to the Copernicus programme and its users. The constellation, for which the first launch is currently planned for the first half of 2022, will be composed of 6 identical VHR imaging satellites with a panchromatic and 8 band multispectral instrument capable of collecting at a spatial resolution of 0.29m at Nadir. While 2 of the Legion satellites will be placed into conventional sun-synchronous orbits, the other 4 will fly in mid-inclined orbits to facilitate a revisit of the complete WorldView satellite constellation over the same target in mid-latitude areas of up to 15 times per day from morning to late afternoon. These new intra-day monitoring capabilities as well as the significantly increased large area mapping capacity at highest spatial resolution that the 6 Legion satellites are going to add to the existing WorldView constellation, will be outlined too.

Introduction

RADARSAT-2 has been a Copernicus Contributing Mission since 2011. During this time, RADARSAT-2 has acquired more than 24,000 images in support of Copernicus, mostly in support of Core Services, in particular for maritime and sea ice monitoring. RADARSAT-2 has also supported Copernicus Security Services and Emergency Management Services, including emergency activation in response to floods, storms and wildfires. The quality of RADARSAT-2 products and the reliability and operational responsiveness of the RA-DARSAT-2 system have been key reasons for the success of RADARSAT-2 as a Copernicus Contributing Mission.

Building upon the substantial heritage of the RADARSAT program, MDA is now developing SARNext, a next generation commercial SAR mission that will provide continuity for current users of RADARSAT-2, including Copernicus and other European customers, and better address emerging needs of the geointelligence market. SARNext combines best in breed features of RADARSAT-2 and the RADARSAT Constellation Mission (RCM) to provide enhanced capabilities to existing and new users. Significant SARNext innovations result in improved access, better revisit, broader swath coverage, lower noise, less data compression, faster data rates, and finer resolution. As of April 2022, SARNext development is approaching the mission level critical design review.

This paper will provide a high-level description of the current design of the SARNext mission including orbit, imaging geometry, modes, and operations. Some mission features described here may be subject to change.

SARNext Orbit

To better address strong commercial demand for SAR imagery at low to mid latitudes, SARNext will use a medium inclined (53.5) orbit rather than a near polar orbit, as used by many previous SAR missions. The orbit altitude (~600 km) is similar to that of RCM. A repeat cycle of just under 10 days has been selected to balance full access between ± 62.5° latitude (89% global access) with revisit time, incidence angle diversity and change detection latency. This medium inclined orbit is not sun-synchronous. The local time at nadir will decrease by about 20 minutes per day. The novel orbit inclination and varying local time will change how and when we observe the world with SAR.

The shift to an inclined orbit raises challenges on power and thermal management of the satellite payload and platform. These challenges are being resolved through both satellite design and concept of operations.

Imaging Geometry and modes

SARNext will provide left- and right-looking imaging with a 700 km accessible swath. Incidence angles range between 25 deg and 64 deg. Due to increased power, aperture and downlink, SARNext modes are designed to provide marked improvements in resolution, swath width and sensitivity as compared to equivalent RADARSAT-2 and RCM modes.

SARNext imaging modes include:
- ScanSAR modes designed specifically for detecting vessels of minimum length 50 m (500 km swath), 25 m (450 km) and 15 m (250 km) in sea state 5
- General purpose ScanSAR modes ranging between 30 m and 140 m resolution and 250 km and 700 km swath, for wide area marine applications such as oil spill detection
- Stripmap modes providing 8 m (120 km – 180 km), 5 m (100 km - 180 km) and 3 m (50 km) resolution
- A Spotlight mode providing 3 m × 1 m resolution (10 km × 7 km) [ground range x azimuth]
The attached Figure lists swath widths of these imaging modes. Single, dual and compact-polarisation will be available with all modes except for high incidence vessel detection modes, which are only available with single polarisation.

SARNext Operations

In keeping with RADARSAT heritage, SARNext will be used extensively for maritime surveillance and other time critical applications, for example, land intelligence and disaster response.

SARNext will support Near Real Time (NRT) applications with high reliability of tasking, acquisition, downlink, processing, image quality and delivery. The system design allows for fast tasking, and simultaneous imaging and downlink with guaranteed priority collections. SARNext tasking will make frequent use of left/right slews to better respond to customer orders. End users can task and receive the imagery they need when they need them.

SARNext will support Fast Tasking under one hour through the Canadian Headquarters System and an extensive network of Global Ground Stations. Downlink will also use this same network as well as dedicated client network stations. SARNext will provide a 15-minute Vessel Detection Service when in contact with any of the Global Ground Stations. A global AIS service will be integrated for NRT Dark Target Detection.

With 20 minutes of imaging capacity per orbit, SARNext is also capable of pre-planned systematic collections for monitoring applications (e.g., forestry, mining, pipelines) including interferometry. SARNext will be maintained in an orbital tube suitable for interferometric exploitation of stripmap and spotlight data. Given the wide coverage of stripmap modes we do not see a need for SARNext to support ScanSAR interferometry. Interferometric observations from the inclined SARNext orbit will be along line of sight vectors that are not available from near polar orbiting SARs. Hence, SARNext will measure novel and complementary surface movement components, potentially supporting full 3-D monitoring of surface movement.

Conclusion

SARNext will provide continuity of C-band SAR data for current RADARSAT-2 users with significant enhancements in terms of frequency and extent of coverage at mid to low latitudes, image quality and responsiveness of operations.