James Spilker, Jr., a father of GPS, has died at 86

James Spilker, Jr., a central figure in the technical development of the Global Positioning System (GPS) and an adjunct professor of aeronautics and astronautics at Stanford, died peacefully on Sept. 24, 2019. He was 86.

Spilker made many technical advances during his long career, but he may be best known for developing the GPS coarse/acquisition (CA) signal in the 1970s, which is today the gateway for all the estimated 4 billion users of GPS. Likewise, his “delay-lock loop” process, developed in the early 1960s, became essential to GPS accuracy.

Persis Drell, Stanford University provost and the James and Anna Marie Spilker Professor in the School of Engineering, said she is honored to have known Jim Spilker and to hold the chair that bears his name. “He was a technical giant who was incredibly generous to Stanford,” she said. “Jim was a wonderful person whose enthusiasm was infectious – this is a tremendous loss.”

“An era is passing,” said friend and colleague Brad Parkinson, a professor of aeronautics and astronautics at Stanford and the driving force behind GPS at the Pentagon in the 1970s. “Jim made so many contributions to GPS – the signal, the original monitor stations and the books that propagated his great knowledge to the next generations. He was always a very positive and creative contributor to the world of position, navigation and timing. We will miss him, but hold him as a wonderful example of engineering and of Stanford graduates.”

James Julius Spilker, Jr., was born Aug. 4, 1933. By his own estimation, he was a sickly child: febrile, technically blind without thick eyeglasses, and shy of 5 feet tall in high school. His mother raised him alone working as a secretary in San Francisco.

Though a bright student in high school, Spilker did not at first apply to college, thinking his mother lacked the financial resources to pay for it. Eventually, however, he found his way into College of Marin, a community college in Northern California. There, two of his science teachers spotted his technical talents and helped the young Spilker transfer into Stanford University’s undergraduate program in 1953. He would go on to earn his BS, MS and PhD degrees in electrical engineering at Stanford, where he became an expert in transistor electronics and communications theory.

He earned his doctorate in 1958, just one year after the Russians launched the Sputnik 1 satellite. Spilker’s first job out of college was with Lockheed Research Labs in Palo Alto, where he invented the delay-lock loop process, an optimal receiver for tracking satellites.

“It produced the finest accuracy and that technology … has been in use for GPS for many, many, many years,” Spilker said in an oral history recorded for the IEEE in 2018.

Throughout the 1960s, Spilker would author or co-author key papers on signal timing technologies that would later make possible the precise tracking of satellites necessary for triangulating a user’s position on the ground. Spilker then joined Ford Aerospace to help build a multi-satellite communications system for the military. From there, he and two Ford colleagues co-founded Stanford Telecommunications, Inc., building the company from three employees to 1,300 by the time it was acquired for some $500 million in 1999, all, Spilker proudly noted, without aid of a single dollar of venture capital.

Spilker was always quick to dispense credit to those who worked with him and helped him along the way. “That was not my doing. I happened to be the leader for much of that time, but this was a team effort of a wonderful team of people … wonderful, wonderful people that I will value forever,” he said. Spilker believed his mission in life was to serve others and use his engineering talents to solve the world’s pressing engineering problems for the benefit of all humanity. He often cited Mother Teresa as a role model.

It was in the early ’70s when Parkinson approached Spilker about collaborating on the original GPS architecture. Though it was then strictly a military project, Parkinson and Spilker always set their sights on civilian applications, where they knew their work would have the most far-reaching effect on society.

“We all recognized that the ultimate main market for this type of technology was not military, it was commercial,” Spilker would tell the IEEE.

Spilker focused his efforts on improving both the accuracy and the economics of GPS. He understood from the first that cost would be a key factor in broad acceptance and worked hard to make the technology affordable. In 2018, Spilker imagined himself back in 1978 looking 40 years into the future: “You’d say one word. The one word would be magic, magic,” he said. Today’s GPS chips cost “just a few cents.”

Spilker and Parkinson would co-author Global Positioning System: Theory and Applications in 1996. It is the standard text for GPS. Spilker’s popular textbook Digital Communications by Satellite, first published in 1977, has seen 10 printings, including one in paperback.

In 2001, Spilker joined Parkinson at Stanford as a consulting professor of aeronautics and astronautics. In 2005, he co-founded the Stanford University Center for Position, Navigation and Time, where he continued to work on satellite navigation.

“A globally recognized contributor to GPS architecture and design, Jim was a pioneer in signal timing technology for which he has received numerous prestigious awards,” said Charbel Farhat, chair of the Department of Aeronautics and Astronautics at Stanford. “To me, Jim was a personal friend, a family friend, and an unequaled supporter of our department. We will deeply miss him, and never forget the great champion he has always been.”

In 2012, Spilker and his wife, Anna Marie, a real estate broker and investor, made a gift of $28 million to name The James and Anna Marie Spilker Engineering and Applied Sciences Building and to establish a permanent professorship in the Stanford School of Engineering.

“Jim Spilker was a technical giant, as his many accomplishments and awards attest,” said Jim Plummer, former dean of the Stanford School of Engineering. “But he was also someone who cared very deeply about the next generation, about education and about finding ways for universities to more effectively tackle the big problems we face today. He was a champion of interdisciplinary research teams. He was a very valuable advisor to me when I was dean and always had thoughtful and often unexpected ideas on how to tackle both opportunities and problems. I will greatly miss him."

Spilker was elected to the National Academy of Engineering, the Air Force GPS Hall of Fame and the Silicon Valley Engineering Hall of Fame, and was a Life Fellow of the IEEE and a Fellow of the Institute of Navigation. He also shared the Goddard Memorial Trophy with his collaborators on GPS. In 2015, he won the Thomas Edison Award from the IEEE.

Earlier this year, Spilker was honored along with Parkinson and industry engineers Hugo Fruehauf and Richard Schwartz with the 2019 Queen Elizabeth Prize for Engineering (QEPrize) for their pioneering work in the development of GPS. The QEPrize, one of the world’s most prestigious engineering accolades, came with a £1 million honorarium to be shared among the team. In gratitude to Stanford Engineering, Spilker donated his share of the QEPrize to the school, a testament to his ever-generous spirit.

He is survived by his wife, Anna Marie Spilker of Half Moon Bay, California; four children: Leslie (Bruce) Dudley, Mark (Karen) Spilker, David (Arlene) Spilker, and Sharon (Bob) Scripps; 12 grandchildren: Justin, Ryan, Amy, Sierra, Jackson, Savannah, Mallori, Derek, Emily, Sandra, David and Erin; a great-granddaughter, Alyson; two great-grandsons, Thomas and Andrew; twin sisters, Evelyn Kunst and Phyllis Freeman; as well as Merry, his German shepherd, and two rescue cats, Siam and Tiger.