America Has a GPS Problem
nytimes.comThe FAA has been removing navigational aids for a while now. If GPS were to go down long term, there could be economic impacts. This is a national security issue.
There are enough over the air transmitters already broadcasting that could be formed into a navigation network, as part of their license, the carrying of position and timing signals could be added as a requirement.
The government should provide the equipment, maintenance, and training to do this.