A method is disclosed. In various examples, the method may include receiving an instruction for generating a signal that comprises a ranging signal and a data signal, and transmitting the signal at least partially responsive to the instruction. In various examples the signal may be transmitted via a terrestrial transmitter for transmitting radio waves having encoded messaging information and timing information for one or more of positioning, navigation and timing. In various examples, the signal may include a pulse group comprising a first pulse having a first start time; and a second pulse having a second start time. The second start time may be an integer number of inter-pulse intervals plus an encoding delay after the first start time. The encoding delay may encode data.

A device is disclosed. In one or more examples, the device may include an antenna to receive a signal encoding timing information for one or more of positioning, navigation, and timing. The signal may include a pulse group comprising a number of ranging pulses and a number of data pulses subsequent to the number of ranging pulses. Respective ones of the number of data pulses may have a phase of either a positive-going phase or a negative-going phase. Data may be encoded using the either positive-going phases or negative-going phases of the data pulses. The device may include a processor to decode the data at least partially responsive to the phases of the respective ones of the number of data pulses.

A smart landing pad comprises a flexible display that shows images or patterns, and a protective layer over the display. The protective layer allows a UAV to land without damaging the display. Locator and range finder devices, coupled to the display, communicate with the UAV. The display is operative for wireless communications with a computer or mobile device that provides on-demand user functions, allowing for dynamically changing or customizing the images/patterns shown on the display. The images/patterns comprise a background area showing changeable images that match an environment where the landing pad is placed, and a target landing area surrounded by the background area. The target landing area includes a changeable insensitive, contrast portion, and changeable marker pattern portions having changeable colors/shapes. The images/patterns also include changeable QR codes on the target landing area. The display is IoT enabled so that data from the landing pad is remotely cloud accessible.

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.

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.

The present disclosure relates to position, navigation and timing (PNT) methods, systems, and transmitters. A method comprises receiving radio-frequency (RF) signals from a plurality of virtual transmitters and determining PNT information of a target object based on information obtained from the RF signals. A system comprises a plurality of virtual transmitters and a receiver. The plurality of virtual transmitters is configured to transmit radio-frequency (RF) signals that include PNT information. The receiver is configured to determine PNT information of a target object based on the PNT information. A transmitter comprises a high-frequency (HF) carrier generator, a waveform generator, and an antenna system. The HF carrier generator generates an HF carrier signal. The waveform generator generates a waveform that includes PNT information. The antenna system transmits the HF carrier signal to generate a subject ionospheric duct. The antenna system is further configured to transmit the waveform through the ionospheric duct.

A target user equipment (UE), which may be a vehicle or UE carried by a pedestrian, may receive sequentially broadcast ranging signals from a set of ranging source entities (SEs), which may be road side units or other vehicles. The target UE further receives location information separately broadcast by each SEs. The location information, for example, may include the position for the SE, the time of transmission of the ranging signals transmitted by the SE and/or a sequence identifier for the SE. The target UE may determine ranges to the SEs using time of arrival measurements for the ranging signals and the time of transmissions of the ranging signals or the sequence identifier received in the location information. The position of the target UE may be determined using the determined ranges to the SEs and the positions of the SEs received in the location information.

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.

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.