GAO: DOD Still Struggling With GPS' M-Code Upgrade

The Defense Department has made progress on upgrading GPS with a military-specific signal -- M-code -- that resists interference and jamming, but it still faces challenges in developing the needed ground, space and user equipment, GAO said Monday. The ground segment modernization needs more testing and demonstration, and the Air Force's development of receivers that process M-code has been delayed, GAO said. It added that delays in satellite delivery raise the possibility of DOD's goal of having M-code-capable satellites in continuous operation being pushed back by years.