An exemplary method for ultra-tight or deep-integrated tracking signals,
transmitted from satellites and containing digital codes, includes a
receiver receiving first and second signals transmitted by a satellite,
and tracking the first and second signals with one integrated filter. The
integrated filter tracks range error, range error rate, range error
acceleration, a carrier integer ambiguity of the first signal, a carrier
integer ambiguity of the second signal, an ionospheric delay error, and
optionally an ionospheric delay error rate.