A long range navigation system may include radio frequency (RF) transmitter stations at fixed geographical locations, each having an RF transmitter and an RF modulator coupled to the RF transmitter, and configured to generate a direct sequence spread spectrum (DSSS) RF signal being spectrally shaped so that 99% of power from the RF transmitter is within the frequency range of 90-110 KHz. Movable RF receiver units each include an RF receiver and a demodulator coupled to the RF receiver configured to demodulate the DSSS RF signal to determine a position of the movable RF receiver unit.

An enhanced LOng RAnge Navigation (eLORAN) system may include a plurality of eLORAN transmitter stations, each configured to transmit respective eLORAN signals at different frequencies. An eLORAN receiver device may be configured to receive the respective eLORAN signals at different frequencies from each of the eLORAN transmitter stations, determine a correction factor based upon the received respective eLORAN signals, and apply the correction factor to determine a geographical position of the eLORAN receiver device.

A method for generating private eLoran signals includes receiving, by a transmitter that is configured to transmit a transmission at a fixed time, a transmission key; determining, by the transmitter, a pseudo-random transmission time for transmitting the transmission, where the pseudo-random transmission time is determined using the transmission key; and initiating transmission, by the transmitter, of the transmission at the pseudo-random transmission time. A receiving device includes a processor that is configured to obtain a pseudo-random time for receiving a transmission from a transmitter; receive the transmission at the pseudo-random time; and use the transmission to determine at least one of a time, a longitude, or a latitude at the receiving device.

A method for generating private eLoran signals includes receiving, by a transmitter site, a transmission key. The transmitter site is configured to transmit a timing signal at a fixed time. The method also includes determining, by the transmitter site, for the timing signal configured to be transmitted at the fixed time, a pseudo-random transmission time for transmitting the timing signal, and initiating transmission, by the transmitter site, of the timing signal at the pseudo-random transmission time.]. A method for receiving private timing signals includes determining, by the receiver device and using the fixed time, a pseudo-random time for receiving the timing signal from the transmitter site, receiving, by the receiver device, the timing signal at the pseudo-random time, and using, by the receiver device, the timing signal to determine at least one of a time, a longitude, and a latitude at the receiver device.

An enhanced Long Range Navigation (eLORAN) system may include an eLORAN controller configured to obtain satellite-derived conductivity data and satellite-derived temperature data for different geographical positions and generate eLORAN correction factors based thereon. The eLORAN system may also include eLORAN transmitter stations. The eLORAN system may also include an eLORAN receiver device that may include an eLORAN receive antenna and an eLORAN receiver coupled to the eLORAN receive antenna and configured to receive the eLORAN correction factors. The eLORAN receiver device may also include a controller coupled to the eLORAN receiver. The controller may be configured to cooperate with the eLORAN transmitter stations to determine an eLORAN receiver position corrected based upon the eLORAN correction factors.

An enhanced LOng RAnge Navigation (eLORAN) system may include a plurality of eLORAN transmitter stations, and at least one eLORAN receiver device. The eLORAN receiver device may include an eLORAN receive antenna, an eLORAN receiver coupled to the eLORAN receive antenna, and a controller coupled to the eLORAN receiver. The controller may be configured to cooperate with the eLORAN transmitter stations to determine an eLORAN receiver position and receiver clock error corrected from additional secondary factor (ASF) data, the ASF data based upon different geographical positions and different times for each different geographical position.

An enhanced Long Range Navigation (eLORAN) system may include an eLORAN controller configured to obtain satellite-derived conductivity data and satellite-derived temperature data for different geographical positions and generate eLORAN correction factors based thereon. The eLORAN system may also include eLORAN transmitter stations. The eLORAN system may also include an eLORAN receiver device that may include an eLORAN receive antenna and an eLORAN receiver coupled to the eLORAN receive antenna and configured to receive the eLORAN correction factors. The eLORAN receiver device may also include a controller coupled to the eLORAN receiver. The controller may be configured to cooperate with the eLORAN transmitter stations to determine an eLORAN receiver position corrected based upon the eLORAN correction factors.

A LORAN device may include a LORAN antenna, a LORAN receiver, an RF signal path extending between the LORAN antenna and the LORAN receiver and being subject to ambient RF interference, and an ambient RF interference canceller coupled in the RF signal path. The ambient RF interference canceller may include an ambient RF interference sensor configured to generate an estimated ambient RF interference signal based on the sensed ambient RF interference, and cancellation circuitry configured to cooperate with the ambient RF interference sensor to generate an ambient RF interference cancellation signal based upon the sensed ambient RF interference signal, and add the ambient RF interference cancellation signal to the RF signal path.

An eLORAN receiver may include an antenna and eLORAN receiver circuitry coupled to the antenna. The antenna may have a ferromagnetic core including a ferromagnetic medial portion and ferromagnetic arms extending outwardly, and a respective electrically conductive layer surrounding each of the ferromagnetic arms and having a slot.

A LORAN device may include a housing, and an electrically short LORAN antenna carried by the housing. The LORAN device may have a LORAN receiver carried by the housing and coupled to the electrically short LORAN antenna, and an RF crystal resonator coupled to the electrically short LORAN antenna so that the electrically short LORAN antenna is forced to a resonant condition for a LORAN receive signal.