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 from the ferromagnetic medial portion, a respective electrically conductive winding surrounding each of the ferromagnetic arms, and an electrically conductive patch element adjacent the ferromagnetic core.

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.

An RF PNT system may include LORAN stations. Each LORAN station may include a LORAN antenna, and a LORAN transmitter coupled to the LORAN antenna and configured to transmit a series of LORAN PNT RF pulses having a time spacing between adjacent LORAN PNT RF pulses. One or more of the LORAN stations may include a message embedding generator coupled to the LORAN transmitter and configured to generate message RF bursts based upon an input message, and with each message RF burst being in the time spacing between respective adjacent LORAN PNT RF pulses.

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.

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.

Various technologies pertaining to integrating a positioning or timing solution from an alternative position, navigation, or timing (PNT) system into a satellite-based-navigation system are described herein. The PNT system generates a position/timing (P/T) solution that indicates a current position or current time of the PNT system. The P/T solution is provided as input to a simulation of a satellite constellation of the satellite-based-navigation system, and a constellation signal is generated based on the simulation and the P/T solution. The constellation signal is formatted according to a navigation signal format of the satellite-based-navigation system such that when the constellation signal is provided to a receiver of the satellite-based-navigation system, the receiver computes a P/T solution that indicates the current position or the current time identified by the PNT system.

Various technologies pertaining to integrating a positioning or timing solution from an alternative position, navigation, or timing (PNT) system into a satellite-based-navigation system are described herein. The PNT system generates a position/timing (P/T) solution that indicates a current position or current time of the PNT system. The P/T solution is provided as input to a simulation of a satellite constellation of the satellite-based-navigation system, and a constellation signal is generated based on the simulation and the P/T solution. The constellation signal is formatted according to a navigation signal format of the satellite-based-navigation system such that when the constellation signal is provided to a receiver of the satellite-based-navigation system, the receiver computes a P/T solution that indicates the current position or the current time identified by the PNT system.

A method of processing times-of-arrival (TOAs), some representing emitted pulses by an emitter and generated from a pulse pattern having a fixed greatest common divisor pulse repetition interval (GPRI), the method including: creating pulse trains each including an initial TOA and a vector of added TOAs, and a corresponding pulse index vector mapping the TOA vector into the pulse pattern consistent with a known TOA tolerance and viable with a known GPRI range of the emitter type; and walking, for each pulse train, each next TOA after the added TOAs, and each next index mapping the next TOA into the pulse pattern, including checking if the pulse train extended by the next TOA and next index is consistent with the TOA tolerance, checking if the extended pulse train is viable with the GPRI range, and if both checks pass, adding the next TOA and next index to the pulse train.

An enhanced LOng RAnge Navigation (eLORAN) system may include a plurality of eLORAN stations, each having an eLORAN antenna and an eLORAN transmitter that may transmit data over an eLORAN data channel and may transmit a series of eLORAN navigation RF pulses. An eLORAN control station may generate station specific eLORAN data and non-station specific eLORAN data, divide the non-station specific eLORAN data into non-specific eLORAN data subsets, and cause each eLORAN station to transmit the station specific eLORAN data and a corresponding non-station specific eLORAN data subset over the eLORAN data channel in a manner to optimize data throughput.