Aircraft guidance with transmitting beacons is disclosed. An example apparatus includes a transceiver of an aircraft to receive signals from deployed beacons, a signal analyzer to analyze the signals to determine distances of the respective beacons relative to the aircraft, and a position calculator to calculate a positional zone of the aircraft based on the distances.

A system and method for providing navigation through an underground space. The method includes receiving ephemeris data of a plurality of satellites in orbit at a location of the underground space, determining a schedule of the plurality of satellites in orbit, obtaining location of a plurality of pseudolites within the underground space, and determining satellite parameters to configure each of the plurality of pseudolites. Satellite parameters are determined based on the obtained location of each pseudolites and the determined satellite schedule. Also, the satellite parameters include at least a signal modulation parameter and a broadcast data parameter. The method also includes configuring each of the plurality of pseudolites with the respective satellite parameters, and controlling the plurality of pseudolites to broadcast satellite signals based on the determined satellite parameters. The broadcasted satellite signals simulate locations of the plurality of satellites in orbit.

A system and method for providing navigation through an underground space. The method includes receiving ephemeris data of a plurality of satellites in orbit at a location of the underground space, determining a schedule of the plurality of satellites in orbit, obtaining location of a plurality of pseudolites within the underground space, and determining satellite parameters to configure each of the plurality of pseudolites. Satellite parameters are determined based on the obtained location of each pseudolites and the determined satellite schedule. Also, the satellite parameters include at least a signal modulation parameter and a broadcast data parameter. The method also includes configuring each of the plurality of pseudolites with the respective satellite parameters, and controlling the plurality of pseudolites to broadcast satellite signals based on the determined satellite parameters. The broadcasted satellite signals simulate locations of the plurality of satellites in orbit.

A positioning system including a satellite signal receiver 20 that receives satellite signals from a plurality of positioning satellites; a plurality of indoor pseudo satellite stations that transmit pseudo satellite signals; and a pseudo station control device that selects the positioning satellites to be allocated to the plurality of pseudo satellite stations based on the received satellite signals, allocates a PRN code corresponding to each of the selected positioning satellites to each of the plurality of pseudo satellite stations one by one, determines a delay time of the PRN code allocated to the plurality of pseudo satellite stations, and transmits a plurality of pseudo satellite signals generated using the PRN code corresponding to each of the plurality of pseudo satellite stations and the delay time to each of the plurality of pseudo satellite stations.

A positioning system including a satellite signal receiver 20 that receives satellite signals from a plurality of positioning satellites; a plurality of indoor pseudo satellite stations that transmit pseudo satellite signals; and a pseudo station control device that selects the positioning satellites to be allocated to the plurality of pseudo satellite stations based on the received satellite signals, allocates a PRN code corresponding to each of the selected positioning satellites to each of the plurality of pseudo satellite stations one by one, determines a delay time of the PRN code allocated to the plurality of pseudo satellite stations, and transmits a plurality of pseudo satellite signals generated using the PRN code corresponding to each of the plurality of pseudo satellite stations and the delay time to each of the plurality of pseudo satellite stations.

A method and transmission system for amplifying and providing navigation signals. The system comprises a splitter circuit configured to receive a plurality of radio frequency (RF) signals oscillating at at least two different frequencies f.sub.1 and f.sub.2. The splitter circuit is further configured to split and forward the RF signals having the f.sub.1 frequency to a first bandpass filter and the RF signals having the f.sub.2 frequency to a second bandpass filter. The system further comprises a first tunable amplifier configured to receive the RF signals from the first bandpass filter. The system further comprises a second tunable amplifier configured to receive the RF signals from the second bandpass filter at substantially the same time as the first tunable amplifier's receipt of the RF signals from the first bandpass filter. The first tunable amplifier is further configured to amplify its RF signals across a first band centered around the frequency f.sub.1. The second tunable amplifier is further configured to amplify its RF signals across a second band centered around the frequency f.sub.2. The amplified RF signals are fed substantially concurrently into a mixer circuit for transmission via an RF antenna to a navigation receiver.

Embodiments describe determining position by selecting a set of digital pseudorandom sequences. The magnitudes of the cross-correlation between any two sequences of the chosen set are below a specified threshold. A subset of digital pseudorandom sequences are selected from the set such that the magnitudes of the autocorrelation function of each member of the subset, within a specified region adjacent to the peak of the autocorrelation function, are equal to or less than a prescribed value. Each transmitter transmits a positioning signal, and at least a portion of the positioning signal is modulated with at least one member of the subset. At least two transmitters of the plurality of transmitters modulate respective positioning signals with different members of the subset of digital pseudorandom sequences.

Embodiments describe determining position by selecting a set of digital pseudorandom sequences. The magnitudes of the cross-correlation between any two sequences of the chosen set are below a specified threshold. A subset of digital pseudorandom sequences are selected from the set such that the magnitudes of the autocorrelation function of each member of the subset, within a specified region adjacent to the peak of the autocorrelation function, are equal to or less than a prescribed value. Each transmitter transmits a positioning signal, and at least a portion of the positioning signal is modulated with at least one member of the subset. At least two transmitters of the plurality of transmitters modulate respective positioning signals with different members of the subset of digital pseudorandom sequences.

Devices, systems, and methods for sending positional information from transmitters/beacons. In one implementation a transmitter generates a range block including a ranging signal and a hybrid block including positioning data, and sends the range block and hybrid block at different times. A user device may receive signals from a plurality of transmitters and generates position/location information using trilateration and measured altitude information in comparison with transmitter altitude information.

Devices, systems, and methods for sending positional information from transmitters/beacons. In one implementation a transmitter generates a range block including a ranging signal and a hybrid block including positioning data, and sends the range block and hybrid block at different times. A user device may receive signals from a plurality of transmitters and generates position/location information using trilateration and measured altitude information in comparison with transmitter altitude information.