For reporting actual, demonstrable GPS constellation errors only (not equipment or user issues): mailto:pnt.office@gps.gov via http://www.gps.gov/support/cont

For reporting actual, demonstrable GPS constellation errors only (not equipment or user issues): mailto:pnt.office@gps.gov via http://www.gps.gov/support/contact/ http://www.gps.gov/support/contact/ (Folks at shops like Trimble and Garmin already have contacts within their respective orgs, so employees should try to work with their channels where possible.)