A low-earth orbit (LEO) satellite operates to: determine an orbital position of the LEO satellite based on the first signaling and based on precise point positioning (PPP) correction data associated with the constellation of non-LEO navigation satellites, wherein the PPP correction data includes orbital correction data and timing correction data associated with the constellation of non-LEO navigation satellites, and wherein the PPP correction data is received separate from the first signaling; determine, based on the inter-satellite communications, an error condition associated with one of the other LEO navigation satellites of the constellation of LEO navigation satellites; and broadcast a navigation message based on the orbital position, wherein the navigation message includes a timing signal and the orbital position associated with the LEO satellite, correction data associated with the constellation of non-LEO navigation satellites, and an alert signal that indicates the error condition associated with one of the other LEO navigation satellites of the constellation of LEO navigation satellites.