Honouring our Advisor Dr. Anthony Freeman on receiving the CBE

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I'm truly honoured to introduce Dr. Anthony Freeman, freshly appointed Commander of the Order of the British Empire (CBE) for advancing UK-US Space and Earth Science.

Dr. Freeman, a member of our Advisory Board, has been one of our closest collaborators since our early days - guiding the systems team on SAR System Design and software processing. But his involvement has been far more integral. He chairs our internal review boards, and works hands on with the team, especially on new innovations like our drone-based SAR system.

What stands out the most is not just his brilliance, but his generosity - with his time, his insights, and his mentorship. He has been instrumental in our progress, as an organization and as individual engineers. Today, we’d like to celebrate his career and achievements and share with the world a glimpse of all that he has accomplished.

Dr. Anthony Freeman spent nearly four decades at NASA’s Jet Propulsion Laboratory, along the way perfecting a deceptively simple idea: make a radar antenna “listen as it sweeps,” unlocking 100s of kilometer-wide images without losing meter-class detail.

That concept, SweepSAR, now forms the heart of NASA-ISRO’s NISAR satellite, slated for launch from India next month. Dr. Freeman’s journey from bus-hopping schoolboy in northern England to CBE-decorated radar visionary offers a master-class in curiosity, persistence and quiet technical audacity.

From Dukinfield to JPL

Growing up in Dukinfield, an industrial town near Manchester, Dr. Freeman won a scholarship to Stockport Grammar School and routinely took three buses each way for classes - an early lesson in perseverance that is evocative of JPL’s motto, “Dare Mighty Things.” He earned degrees in mathematics and astrophysics at the University of Manchester, cut his teeth working on radar systems at Marconi in Chelmsford, and in 1987 accepted an invitation to join the Radar Section at NASA-JPL.

The Wide-Swath Puzzle

By the early 1990s, synthetic aperture radar faced a physics wall: you could map a broad swath or obtain fine resolution, but not both. ScanSAR widened coverage at the cost of blurry pixels, while phased arrays delivered crisp images at eye-watering power and mass. Dr. Freeman, in his role as a radar systems architect at JPL, framed the dilemma in a 2009 IEEE paper that challenged engineers to “break the tyranny of swath versus resolution.”

Inventing SweepSAR

Brainstorming with German Aerospace Center (DLR) colleagues, Dr. Freeman asked what would happen if the receive beam were electronically steered to follow the echo from a reflector antenna as the satellite moved - a bit like sweeping a broom across a floor.

The name honors his family goldendoodle, Sweep - a touch that hints at Dr. Freeman’s understated humor.

Sweep, the family goldendoodle, that bears the name.

Lab demonstrations showed SweepSAR could slash peak transmit power and data-rate penalties compared with conventional ScanSAR, convincing NASA headquarters to back the concept for flight.

Bringing SweepSAR to Space: NISAR

Dr. Freeman was the program lead during the early formulation phase for NISAR (NASA-ISRO Synthetic Aperture Radar), the first satellite to carry dual-frequency L- and S-band SweepSAR instruments. The 2,800-kg observatory will orbit 747 km above Earth, mapping nearly every landmass and ice sheet twice every 12 days with centimeter-level change detection - critical for tracking earthquakes, glacier flow, and biomass loss.

International collaboration is central: ISRO supplies the S-band radar and launches from Satish Dhawan Space Centre, while NASA provides the L-band system and the deployable mesh reflector. Together, they represent the largest radar antenna ever flown on a NASA Earth-science mission.

Mentor, Innovator, and CBE

Beyond SweepSAR, Dr. Freeman led JPL’s Innovation Foundry from 2012 to 2019, a skunkworks where mission concepts are stress-tested early to fail fast and learn quicker. He also chaired JPL’s “CubeSat Kitchen Cabinet”, championing a CubeSat initiative that seeded many of JPL’s small-sat missions and now informs PierSight’s own ocean-monitoring constellation. He also found time to publish, including an influential paper on “Design Principles for SmallSat SARs”, presented at the annual SmallSat conference in the US.

The UK recognised these contributions in the 2025 New Year Honours, naming him a CBE “for services to UK/US relations in space and Earth science.” Local press in California’s Central Coast celebrated the award, noting his pride in SweepSAR and his plans to keep mentoring young engineers even in retirement.

Looking Ahead with PierSight

Today, Dr. Freeman advises PierSight on applying SAR principles to backpack-sized satellites that will monitor every ship, every hour, transforming oceans into a real-time data layer for safety, security, and climate stewardship.

There’s a lot we could learn from the restless curiosity that took him from rainy Dukinfield bus stops to the threshold of global, persistent Earth observation. Here at PierSight, we’re honored to have that opportunity as we take on a complex challenge.

Q&A with Dr. Freeman

What does receiving the CBE from the King mean personally and professionally?

It’s great honour of course, and one I wasn’t expecting at all from my country of origin. It’s a lovely way to mark this final phase of my career.

What was your exact role on NISAR?

I was the program lead during the early formulation of NISAR, when the system architecture (including SweepSAR) was established.

What technical hurdles must CubeSat-class SAR still overcome for global persistence?

The most obvious challenge is thermal balancing of the spacecraft, basically radiating out all the waste heat generated when the SAR is operating. A second challenge is the sheer volume of data a SAR generates. Both factors can limit the on-time of an individual CubeSat-class SAR in a constellation.

What does the future of radar-based Earth Observation look like? Say 10-15 years from now.

I think there’ll be AI deployed everywhere in the signal processing chains to extract information from the high-resolution data streams, and a lot of moderate resolution radar sensing, e.g. for soil moisture, ocean winds and currents, will be done using passive radars that exploit Signals-of-Opportunity generated by the Telecom mega-constellations (e.g. Starlink, Kuiper, OneWeb).

JPL’s Innovation Foundry fostered “fail-early” culture. What lesson should startups borrow?

We realized that if we didn’t have one or two failures along the way, we weren’t truly innovating. Also to make sure we designed in the capacity to upload software upgrades to fix on-orbit problems.

What drew you to advise PierSight?

After I met Gaurav, I saw in him a kindred spirit, who was willing to challenge the conventional wisdom. I’d advised Capella Space technically early on when they were just starting out, and I thought Gaurav and PierSight had a fresh take on how to do SAR in a SmallSat package, that I could be useful in helping guide.

You’ve mentioned an interest in sci-fi. What are a few of your favourite books or ones that you’d recommend?

My favourite sci-fi movie is Bladerunner, and my favourite book is probably Dune.

We were also lucky to get a few wonderful photos from Dr. Freeman of one of his personal passions: maintaining his classic MGB and keeping it roadworthy.

Our experience working with Dr. Freeman

“Tony is one of the most knowledgeable people I know of in the world of SAR. But what’s even more striking is his humility. Despite his stature, he’s never hesitant to say, “I don’t know,” when he isn’t confident about something. That kind of honesty is rare, especially at his level, where many feel the pressure to have all the answers. There’s so much we have learnt from him: how to say no with clarity, how to document your thoughts, and he continues to push us to do better - sometimes with a three-page memo in response to a simple question! It’s a rare gift to work with someone who’s shaped the field you’re building in. And even rarer when that someone is as humble and generous as Tony.” – Gaurav Seth, CEO and Co-founder

“We are privileged to receive guidance and support from Dr. Anthony Freeman, whose innovations in the field of Synthetic Aperture Radar are globally well known. Even after achieving so much in life, Dr. Freeman interacts with our young engineers and patiently guides them to achieve excellence in the field of SAR. His expertise and dedication inspire us to strive for excellence every day.” – Vinit Bansal, CTO and Co-founder

“From using Dr. Freeman’s decomposition methods to analyze soil on the Moon and forests on the Earth, to having him on my onboarding call at PierSight, has been a surreal experience for me. Witnessing the depth of his knowledge, his humility despite the magnitude of his achievements and the effortless authority to say ‘Oh, I have a paper on this’ to every doubt or question we had, has been inspirational on both personal and professional levels. This honor is much deserved Tony. A well-deserved chapter in a legacy that merits even more.” – Hamish D’souza, Data Science Engineer

“Dr. Freeman is a SAR legend in its absolute sense. He is a man who can say 'been there, done that' for literally every aspect of building a Synthetic Aperture Radar. Getting the opportunity to know him and work with him has been a true honour." – Ishan Khare, System Design Engineer