Obituary: Professor James Spilker, Jr

With his key contributions to the development – and subsequent enhancement – of GPS, it would be hard to exaggerate the profound impact of Professor Spilker’s work. Today, over four billion people around the world benefit from his efforts, and myriad applications stemming from his work are intricately woven into the fabric of daily life. In addition to promoting GPS technologies, Spilker also focused on education and philanthropy throughout his career, donating much of his time and money to the improvement of engineering education and the fields of aeronautics and astronautics.

Lord Browne, Chairman of the Queen Elizabeth Prize for Engineering Foundation said: “The engineering community is deeply saddened by the death of Professor James Spilker, Jr. Jim exemplified the profound impact that an engineer can have on the world and encouraged the next generation to live up to that potential.

“His work, along with that of his three fellow laureates, on the Global Positioning System remains cutting-edge nearly half a century later, and we will continue to benefit from their remarkable efforts for years to come.”

Sir Christopher Snowden, chair of the QEPrize international judging panel added: “James Spilker was a true innovator and his exceptional engineering contributions to the Global Positioning System (GPS), which were recognised by the recent award of the Queen Elizabeth Prize for Engineering, have benefited the world and inspired younger engineers.”

Early life

Spilker, legally blind from youth, did not initially apply for university after graduating from high school, instead opting to attend a nearby community college. While studying at the College of Marin, Spilker’s keen aptitude for chemistry impressed the professors, who committed to help him get into Stanford University via a scholarship. Scoring at the 99.99% level in his mathematics entrance exam, Spilker was awarded the scholarship and proceeded to earn his undergraduate degree, Master’s, and PhD in electrical engineering in just five years by the age of 23.

His first job following university was at Lockheed Research Labs, where he worked predominantly in communication theory and invented an optimal tracking receiver, called the delay-lock loop, to enable precise tracking of satellites. This later proved to be key for tracking Code Division Multiple Access (CDMA) signals from GPS satellites and improved the overall accuracy of the system. Spilker then moved to Ford Aerospace, where he designed and implemented the payload for the world’s first military satellite communications system.

In the early 1970s, Spilker, together with two other senior engineers at Ford Aerospace, formed Stanford Telecommunications Inc. In 1973 the company was contracted by Colonel Bradford Parkinson, the chief architect behind GPS. Spilker took responsibility for the work and co-invented a separating system, split spectrum mode, which allowed GPS to broadcast civilian and military signals using different frequencies.

The resulting signals were precise, resistant to jamming, and allowed multiple satellites to broadcast on the same frequency without interfering with each other. They provided sub-centimetre level accuracy, and, when later opened up to the public, gave the world access to a transformative positioning system with applications ranging from navigation and disaster relief through to climate monitoring systems, banking systems, and the foundation of tomorrow’s transport, agriculture, and industry. His team also developed and built the first receiver to process the GPS satellite signals, and they operated a special receiver in orbit to verify the continued operation of the satellites in the intense radiation of the upper Van Allen belt.

Spilker remained at Stanford Telecommunications Inc. until 1999, building the company to 1,300 staff across five US states. Stanford Telecommunications Inc. was successfully sold in 1999, allowing Spilker to return to Stanford University to share with students, faculty and the world his professional knowledge and entrepreneurial experiences and further the progress of GPS and PNT. In 2001 he was asked to join Stanford’s faculty as an adjunct professor, where he invented a newer, more accurate L5 civil signal (launched a decade later) which was more resistant to interference from space weather. He donated this signal structure to the Federal Aviation Administration (FAA), free of charge.

In 2005, Spilker co-founded the Stanford Research Center for Position, Navigation and Time (PNT) and became the co-founder and executive chairman of AOSense Corporation in 2006. In 2012, he and his wife, Anna Marie Spilker, donated US $28 million to Stanford University, gifting The James and Anna Marie Spilker Engineering and Applied Sciences Building, as well as endowing a professorship in the School of Engineering.

During his professorship, Spilker enjoyed talking to his students about the potential they have as engineers to change the world. In an interview last year with Charles Rino at the Computer History Museum, Spilker said: “As I have the opportunity to talk to our students, not only from Stanford, but other schools around the world, I think that one of my messages to them is that as they develop world-changing technology that serves the world, they should always look to see how they can create functions that serve the world and benefit humanity in all continents around the world. And I was able to do that a trifle. They will be able to do that in wondrous ways that we will not even understand at all now.”

Awards and memberships

Spilker earned an impressive collection of awards throughout his life for his pioneering work and innovation. In addition to receiving the 2019 Queen Elizabeth Prize for Engineering alongside Bradford Parkinson, Hugo Fruehauf, and Richard Schwartz, Spilker was awarded the Arthur Young Entrepreneur of the Year Award in 1987, the ION Kepler Award in 1999, and the Burka Award in 2002. In 2000, he received the US Air Force Space Command Recognition Award for 9 years of service on GPS, and he was awarded the IEEE Edison Gold Medal in 2015 for contributions to the development and implementation of the GPS civilian navigation system.

Spilker was a Member of the National Academy of Engineering (NAE), a member of the NAE Peer Review Committee of the NAE for Electronics; a Life Fellow of the IEEE, which recently bestowed on him its Thomas Edison Award; and was the Chairman of the IEEE Technical Advisory Committee.