https://blogs.scientificamerican.com/observations/a-pioneer-of-gps-passes-away/

In February 2019, my husband, James Spilker Jr., and I celebrated the news that he, along with his colleagues Brad Parkinson, Hugo Fruehauf and Richard Schwartz, would receive the Queen Elizabeth Prize for Engineering, the most prestigious engineering award in the world, for their groundbreaking work on the Global Positioning System (GPS). GPS was, and continues to be, a tremendous feat of engineering that required the development of new satellites, atomic clocks and GPS receivers.

When GPS launched in the 1970s, it helped the U.S. military to improve its navigation and, subsequently, it contributed immeasurably to mobile mapping applications. Now, nearly 50 years later, the same steady GPS signals that Jim designed and proposed in the 1970s, are used in everything from monitoring tectonic plates and glaciers to banking to tracking all mobile devices including those for Alzheimer’s patients and parolees.