Umbra SAR Constellation

Quick facts

Overview

Related Resources

Summary

Mission Capabilities

Each Umbra satellite houses a centre-fed parabolic mesh reflector SAR antenna, designed for high bandwidth and efficiency in order to operate seamlessly from data tasking to delivery. The planned full constellation will harmonise 32 SAR sensors operating in low Earth orbit (LEO) to support critical and persistent observation of the Earth for sectors including intelligence, defence, emergency response, disasters, urban planning, and maritime.

Performance Specifications

The satellites prioritise two imaging modes: Spotlight mode, which facilitates high resolution, multi-look SAR imagery; and Extended Dwell mode, designed for extended observations of fixed targets. Extended Dwell mode facilitates additional imaging capabilities including SAR video, low-noise, and Colour Sub-aperture imagery. Both imaging modes capture 5 km x 5 km scenes as standard, with resolutions as low as 0.25 m.

The Umbra SAR satellites orbit in a Sun-synchronous orbit of 560 km altitude and 97.4-degree inclination. The high agility of the satellites allows for revisit periods less than one hour for latitude bands ± 67 degrees.

Space and Hardware Components

The high agility and dwell capabilities of the Umbra SAR satellites is a result of their ability to squint - the steering of a radar beam to cover different perspectives. Each microsatellite features a 70 kg mass, five year design life, and fits on an Evolved Expendable Launch Vehicle, or EELV, Secondary Payload Adapter (ESPA).

Overview

Umbra is a US-based commercial space company, established in 2015, that offers vertically-integrated services to governments and commercial partners through high spatial and temporal resolution SAR imagery, as well as custom mission solutions. Umbra provides end-to-end space-based intelligence data services, including persistent all-weather, day-and-night radar monitoring to support diverse operational needs.

Umbra has developed and currently operates a synthetic aperture radar (SAR) constellation capable of  delivering high quality SAR imagery to commercial and government customers for rapid, actionable insights. The mission emphasizes global coverage and frequent revisit capability to support sustained situational awareness at scale. The constellation facilitates critical and persistent monitoring applications across intelligence, defence, emergency response, disaster management, urban planning, and maritime domains. Umbra’s mission is designed to complement existing Earth observation systems by providing reliable radar data where optical sensing is constrained, enabling continuous monitoring of dynamic and contested environments. Umbra has also secured strategic partnerships and government contracts that integrate its SAR data into broader intelligence and Earth observation frameworks. 

The Umbra constellation is planned to contain 32 satellites, with its first, Umbra-01 launched in June 2021. The constellation also includes tandem pairs designed to enable advanced imaging modes, and is being scaled to increase coverage, revisit frequency, and data availability. SAR instruments use a powerful active remote sensing technology that can image through the cover of night, clouds, smoke, and rain, unlike optical instruments which are limited to unobstructed sunlit conditions. This all-weather, all-illumination capability allows the mission to deliver reliable, persistent monitoring and change detection across a wide range of environments supporting intelligence, environmental, and operational decision-making with high-resolution SAR products integrated into commercial and government workflows. 1) 2) 17) 3) 16) 21)

Spacecraft

Each satellite uses a 300-watt solid-state power amplifier (SSPA) to drive the radar transmit signal, delivering sufficient power for high-quality imaging performance. The spacecraft employs a stabilized platform with three-axis attitude control using reaction wheels and magnetorquers for precise pointing and maneuvering. The onboard avionics architecture is based on radiation-tolerant components to support operation in low Earth orbit. Umbra satellites include onboard processing capabilities to manage radar data before downlink. Thermal control is achieved through passive radiators and thermal coatings designed to maintain operational temperatures across varying orbital conditions. The communication system uses S-band and X-band frequencies for telemetry, command, and data downlink, with secure links to ground stations.

Power is provided by deployable solar arrays coupled with rechargeable lithium-ion batteries to ensure continuous operation through eclipse periods. 25)

Launches

Orbit

The Umbra SAR constellation orbits in a Sun-synchronous, 560 km orbit, inclined at 97.4 degrees. Umbra achieves an approximate repeat cycle of seven days. Despite this repeat capacity, the satellites’ ability to squint permits observations outside of the observation track, and a rapid revisit time around the globe. 2)

Mission Status

• November 28, 2025: Umbra 11 was launched aboard a Falcon 9 rocket by SpaceX, as part of the Transporter 15 Rideshare mission. The launch took place at 18:44 UTC from Vandenberg Space Force Base, SLC-4E, in California. 22) 24)
• July 31, 2024: Umbra announced a new service dedicated to developing SAR satellites for customers, leveraging the company’s ‘vertically integrated’ structure. Umbra’s Mission Solutions line aims to offer custom satellite solutions ranging from satellite platforms and payloads to full constellations. 6)
• April 30, 2024: Umbra progressed to phase II of the Defense Advanced Research Projects Agency (DARPA) Distributed Radar Image Formation Technology (DRIFT) programme. The programme aims to advance satellites flying formation and data collection techniques with Umbra SAR satellites. Developments in Umbra’s SAR capabilities offer the US Government with new radar opportunities and applications. 7) 8)

Phase II of the programme will involve a multi-month data collection campaign, consisting of bistatic and multistatic datasets for DARPA analysis. Phase II will conclude with a dedicated in-orbit demonstration of Umbra’s multistatic capabilities.

• March 7, 2024: Umbra announced the upcoming release of bistatic SAR imagery, from the constellation’s first tandem pair of satellites, Umbra-07 and -08, which launched in November 2023. Umbra plans to release the remainder of the planned 32-satellite constellation in pairs, which would form a cluster formation capable of multistatic SAR imaging. These enhanced capabilities will serve applications for surveillance, elevation modelling, high resolution imaging, and moving target indication. 9)

Bistatic SAR involves using a spatial separation between the instrument’s transmitter and receiver, which reduces the risks of jamming and creates interferometric applications, known as InSAR. InSAR is a crucial tool for monitoring dynamic events like Earthquakes and for automatic target detection and classification. 10)

Read more about InSAR here.

• March 1, 2024: Umbra announced the free and public release of over 3,000 SAR images in the last year. Since the company’s Open Data Programme’s launch in March 2023, over $4 million of SAR imagery has been released to the public for free. 11)
• October 2, 2023: Umbra was selected as a provider for NASA’s Commercial Satellite Data Acquisition (CSDA) programme, in a five-year contract to acquire SAR data for NASA research. Umbra offers the highest commercially-available SAR imagery, providing NASA with all-weather and time imagery for augmentation with NASA’s existing data collection. 12)
• September 4, 2023: Umbra announced a new partnership with European Space Imaging (EUSI), to develop high resolution optical and SAR European remote sensing products. Optical and SAR imagery around Europe and North Africa at 30 cm and 25 cm resolutions, respectively, can be accessed from one source. EUSI can now harmonise optical and SAR data to guarantee acquisitions irrespective of weather or time of day. This collaboration will develop the companies’ capabilities for emergency response, maritime, and defence applications. 13)
• August 7, 2023: Umbra acquires the highest resolution commercial SAR satellite image, at an astonishing 16 cm x 16 cm. This resolution (as of August 2023) will permit observations of the Earth’s surface details with unparalleled accuracy. 14)

• April 18, 2023: Umbra released first light imagery from Umbra-06, which was acquired less than 48 hours after launch. 15)

• June 25, 2021: Umbra successfully launched the constellation’s first satellite, Umbra-01, initially named the Umbra SAR 2001 radar-imaging microsatellite, onboard SpaceX’s Falcon 9 Transporter-2 mission. The mission launched from Cape Canaveral, Florida. 16)

Sensor Complement

Synthetic Aperture Radar (SAR) System

Umbra’s SAR instrumentation is designed for high spatial and temporal resolution imaging applications, which requires a high bandwidth and efficiency in order to operate seamlessly from tasking to delivery. Specifications for the constellation’s SAR instrument are presented in Table 4 below.

Imaging Modes

The Umbra SAR Constellation features imaging modes suited to a variety of observations, with a number of modes in development that will expand the constellation’s capabilities. 3)

Spotlight Imaging

Spotlight imaging is a SAR imaging mode commonly used to make high spatial resolution observations, whereby the beam direction is focused onto the target area as the spacecraft moves in orbit. This mode permits the extraction of fine topographical details from a scene, as the spacecraft squints at a desired viewing angle. The dwell time is governed by the desired ground plane resolution. A longer dwell creates a longer synthetic aperture and therefore a better resolution. 3) 20)

The standard scene size for Umbra spotlight imagery is 5 km x 5 km, with an additional 10 km x 10 km extended scene size product. A typical Spotlight observation will consist of either single, two, or multiple ‘looks’ - the number of acquisitions gathered as the satellite squints over a target. Spotlight imagery is offered at resolutions between 0.25 and 1 m, at either HH or VV polarisations.

Extended Dwell Imaging

Umbra’s Extended Dwell data product is an extension of the Spotlight imaging mode that tracks a fixed scene for a longer period of time to generate a range of SAR imagery formats. Such imagery includes Dwell Spotlight, a low-noise and high resolution image; Colour Sub-Aperture, a processed image that utilises the unique reflectance spectral fingerprints of man-made objects; and SAR video, a collection of SAR images acquired during an extended dwell observation. 4)

The standard scene size for extended dwell is 5 km x 5 km, at 1 m resolution and either HH or VV polarisation.

Future Imaging Modes

Umbra also plans to implement imaging further imaging modes to the constellation, including Stripmap, Mosaic, and Scan. Stripmap mode is geared towards gathering imagery across wide swaths, up to hundreds of square kilometres while maintaining high resolution. 3)

Mosaic imagery will enable Spotlight imagery to be stitched together to form a large and contiguous scene. This mode will facilitate observations over large areas at no resolution cost.

Scan mode is designed for observations covering large areas at a lower resolution, suitable for oceanography and ship monitoring applications.

Ground Segment

Umbra SAR Data Products

Umbra intends to provide only SAR data products, not insights and analytics.

Umbra offers a wide range of levels and formats of SAR data products, which are described in detail in the Umbra Product Specification Guide. Umbra data can be tasked and acquired through the company’s Canopy tool. 5)

Alternatively, freely available SAR data can be accessed through the company’s Open data programme, which consists of multi-looked spotlight observations of over 1000 locations.

The data products offered by Umbra are broadly classified into Detected and Complex products. Detected products solely use the radar signal amplitude, which defines the strength of pixel values in a greyscale image - the most common SAR visualisation. Complex products make use of the phase of a radar signal for interferometric techniques and applications like InSAR. 3)

Umbra’s Open Data Program monitors more than 20 global locations for change detection and time-series analysis, with weekly updates to support users exploring SAR data over time. Spotlight mode data in the Open Data catalogue is offered at multiple resolutions, including 25 cm, 35 cm, 50 cm, and 1 m, as well as multi-looked spotlight imagery across hundreds of global sites. All Open Data products are provided under a Creative Commons license to allow broad reuse and experimentation. 26)
Umbra’s Open Data catalogue comprises a substantial volume of freely available imagery and metadata. The open repository contains over 17 TB of files, organised with naming conventions that identify the capture time, satellite, and product type. The delivered files include multiple formats such as Compensated Phase History Data (CPHD), Sensor Independent Complex Data (SCID), Geo‑Ellipsoid Corrected Data (GEC), and Sensor Independent Derived Data (SIDD), many of which can be opened natively in GIS software like QGIS or ArcGIS Pro. 27)

Umbra’s ground segment comprises commercial ground stations operated by Kongsberg Satellite Services (KSAT) and AWS Ground Stations, supporting both SAR payload data downlink and telemetry, tracking & command (TT&C) communications. Mission control is based at Umbra’s headquarters in Santa Barbara, California, with provisions for mobile backup and 24/7 operations, ensuring continuous constellation monitoring and control. Regulatory authorizations are in place or being updated for these ground stations to communicate with the Umbra system. 25)

References  

1) “Umbra Satellites,” Umbra Product Guide, URL: https://help.umbra.space/product-guide/umbra-satellites 

2) “Umbra Product Guide,” URL: https://help.umbra.space/product-guide

3) Garcia LP, Furano G, Ghiglione M, Zancan V, Imbembo E, Ilioudis C, Clemente C, Trucco P. Advancements in on-board processing of synthetic aperture radar (SAR) data: enhancing efficiency and real-time capabilities. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing. 2024 Jun 3.

4) “Umbra Products,” Umbra Product Guide, URL: https://help.umbra.space/product-guide/umbra-products

5) “Umbra launches worlds most capable commercial radar-imaging satellite,” Umbra Press Release, June 25, 2021, URL: https://umbra.space/blog/umbra-launches-worlds-most-capable-commercial-radar-imaging-satellite/

6) “Dwell Overview,” Umbra Remote Sensing, URL: https://umbra.space/remote-sensing/dwell/

7) “Satellite: UMBRA,” WMO OSCAR, URL: https://space.oscar.wmo.int/satellites/view/umbra

8) “Krebs, Gunter D, “Umbra-SAR 2001,” Gunter's Space Page, Retrieved August 16, 2024, from https://space.skyrocket.de/doc_sdat/umbra-sar-2001.htm

9) “Umbra offers the world’s most capable SAR satellites to customers,” Umbra Press Release, July 31, 2024, URL: https://umbra.space/blog/umbra-offers-the-worlds-most-capable-sar-satellites-to-customers/

10) Gierull CH, “Bistatic synthetic aperture radar,” Defence R&D Canada - Ottawa, November 2004, URL: https://people.ece.ubc.ca/~yewn/papers/DRDCbistatic.pdf

11) “DARPA selects Umbra for their DRIFT program,” Umbra Press release, May 22, 2023, URL: https://umbra.space/blog/darpa-selects-umbra-for-their-drift-program/

12) “Umbra Unveils Bistatic SAR Data from its Tandem Pair of Satellites,” Umbra Press release, March 7, 2024, URL: https://umbra.space/blog/umbra-unveils-bistatic-sar-data-from-its-tandem-pair-of-satellites/ 

13) Gierull CH, “Bistatic synthetic aperture radar,” Defence R&D Canada - Ottawa, November 2004, URL: https://people.ece.ubc.ca/~yewn/papers/DRDCbistatic.pdf 

14) “Umbra Releases Over $4 Million in Free SAR Data,” Umbra Press Release, March 1, 2024, URL: https://umbra.space/blog/umbra-releases-over-4-million-in-free-sar-data/ 

15) “NASA selects Umbra for its CSDA Program,” Umbra Press Release, October 3, 2023, URL: https://umbra.space/blog/nasa-selects-umbra-for-its-csda-program/ 

16) “Umbra partners with EUSI to offer SAR imagery to European remote sensing projects,” Umbra Press Release, September 4, 2023, URL: https://umbra.space/blog/eusi-partners-with-umbra-to-offer-sar-imagery-to-european-remote-sensing-projects/ 

17) “Umbra Space releases highest resolution commercial satellite image,” Umbra Press Release, August 7, 2023, URL: https://umbra.space/blog/umbra-generates-the-highest-resolution-commercial-satellite-image-ever-released/ 

18) “Umbra achieves first light in under 48 hours,” Umbra Press Release, April 18, 2023, URL: https://umbra.space/blog/umbra-achieves-first-light-in-under-48-hours/ 

19) Lacomme et al, “Electronically Steered Antennas,” Air and Spaceborne Radar Systems, William Andrew Publishing, 2001, Pages 457-467, URL: https://doi.org/10.1016/B978-189112113-5.50028-0 

20) “Canopy,” Umbra Canopy, URL: https://docs.canopy.umbra.space/docs/introduction 

21) Space Voyage Ventures Team, “Umbra Space: Advanced SAR Satellite Solutions and Innovations”, Space Voyage Ventures, September 7, 2025, URL: https://spacevoyageventures.com/umbra-space  

22) Gunter’s Space Page, “Umbra-SAR 2001”, URL: https://space.skyrocket.de/doc_sdat/umbra-sar-2001.htm  

23) WMO OSCAR, “UMBRA”, URL: https://space.oscar.wmo.int/satellites/view/umbra  

24) Clark Stephen, “SpaceX launches 140 spacecraft on Transporter-15 rideshare mission”, SpaceFlightNow, November 28, 2025, URL: https://spaceflightnow.com/2025/11/28/live-coverage-spacex-to-launch-140-spacecraft-on-transporter-15-rideshare/  

25) Jung Gabrielle, “Orbital Debris Assessment Report - For Umbra Satellite Constellation”, June 16, 2021, Umbra, URL: https://fcc.report/IBFS/SAT-LOA-20210616-00080/9512306.pdf  

26) Umbra, “Open data program”, URL: https://umbra.space/open-data/  

27) Litwintschik Mark, “Umbra's Open Satellite Feed”, tech Blog, April 18, 2024, URL: https://tech.marksblogg.com/umbra-open-data-free-satellite-imagery.html