What happened to GPS in Denver?

Photo: YayaErnst/iStock/Getty Images Plus/Getty Images Something big happened to GPS service in the Denver area on Jan. 21. On that day, Air Traffic Control issued a notice advising pilots of problems with GPS reception spanning about 8,000 square miles in…
GPS problems bedevil Denver light rail

Denver’s RTD light-rail system has bragged that “RTD is one of the few transit agencies, nationally, to meet Congress’ original Dec. 31, 2015 deadline” for instituting Positive Train Control (PTC). Yet reception of the GPS signals upon which their PTC…