A method and system are disclosed for providing an estimate of a location of a user receiver device. The method involves emitting, from at least one vehicle, at least one spot beam on Earth; and receiving, with the user receiver device, at least one spot beam. The method further involves calculating, with the user receiver device, the estimate of the location of the user receiver device according to the user receiver device's location within at least one spot beam. Each spot beam contains at least one acquisition signal, which may comprise at least one ring channel. Each ring channel comprises a frame count; a space vehicle identification (SVID); a spot beam identification (ID); and/or X, Y, Z coordinates of the vehicle emitting the spot beam relative to an Earth coordinate system. In one or more embodiments, at least one vehicle may be a satellite and/or a pseudolite.