The present disclosure provides a cross-correlation based method, a system and a storage medium for blind electromagnetic interference Doppler estimation from a single satellite geolocation system. The method includes at a first time, calculating a power spectral density (PSD) of a received signal; smoothing the PSD of the received signal using moving window average, and saving the smoothed PSD of the received signal as PSD0; at a next time, calculating a PSD of another received signal; smoothing the PSD of the another received signal using moving window average, and saving the smoothed PSD of the another received signal as PSD1; performing cross correlation between PSD0 and PSD1 to obtain a cross-correlation result; determining a peak position from the cross-correlation result; and obtaining a Doppler estimation based on a peak position shift between the peak position and a reference position.

First information corresponding to a radio signal received at a first sensing device from a candidate location is obtained. Second information corresponding to a radio signal received at a second sensing device from the candidate location is obtained. A first relationship between the first sensing device and the candidate location and a second relationship between the second sensing device and the candidate location are determined. A first inverse and a second inverse of respectively the first and second relationships are obtained. A first estimate of the radio signal at the first sensing device is determined from the first information and the first inverse. A second estimate of the radio signal at the second sensing device is determined from the second information and the second inverse. Energy emitted from the candidate location is measured based on the first estimate and the second estimate.

First information is obtained from a sensing device at a first time. The first information corresponds to a radio signal received at the device from a candidate location. The device is at a first location at the first time. Second information is obtained from the device at a second time. The second information corresponds to a radio signal received at the device from the candidate location. The device is at a second location at the second time. A system determines that a pattern is in each of the first and second information and determines relationships between the candidate location and the device at each first and second location. The system obtains inverses of the relationships and determines estimates of the received radio signals based on the information and inverses. The system measures or estimates energy emitted from the candidate location based on the estimates.

Systems, methods, and devices are disclosed herein for Doppler based position estimation. Systems may include an antenna configured to receive a radio frequency (RF) signal from an emitter, and configured to generate an output signal based on the received RF signal. Systems may also include a receiver configured to receive the output signal from the antenna. The receiver may include one or more processors configured to identify a plurality of initial conditions for a plurality of state variables associated with the emitter, obtain a measurement of the RF signal from the emitter and an estimate of an uncertainty associated with the measurement, and generate an output based, at least in part, on an updated estimate of the plurality of state variables, the output identifying a position, velocity, and carrier frequency of the emitter. Systems may also include a communications interface configured to communicatively couple the antenna with the receiver.

In an aspect, a wireless entity may transmit a first indication of one or more Doppler error group (DEG) identifiers (IDs) corresponding to one or more DEGs supported by the wireless entity, where each of the one or more DEGs is associated with a hardware configuration or an operational state of the wireless entity. The wireless entity may transmit a first set of measurements associated with a DEG ID of the one or more DEG IDs.

An Automatic Identification System (AIS) for tracking a plurality of maritime vessels may include a ground AIS server and a constellation of Low-Earth Orbit (LEO) satellites in communication with the ground AIS server. Each LEO satellite may include an AIS payload configured to receive AIS messages from the plurality of maritime vessels and determine therefrom reported vessel position data, determine an actual frequency of arrival (FOA) for each of the AIS messages, determine an expected FOA for each of the AIS messages based upon the reported vessel position data for each AIS message, determine a potential spoofing maritime vessel based upon a difference between a corresponding expected FOA and actual FOA for a given AIS message, and send a potential spoof alert to the ground AIS server.

The present application discloses a method and device for determining information, which are used to implement terminal positioning based on carrier signal phase measurement values and improve terminal positioning accuracy. The method for determining information provided by the present application includes: receiving the carrier signal discontinuously sent by the network side; determining the carrier signal phase measurement value for positioning the terminal based on the carrier signal discontinuously sent by the network side.

Disclosed are techniques for positioning a user equipment (UE). In an aspect, a location server receives a first propagation time measurement and a first plurality of OTDOA RSTD measurements from a first UE at a first time, receives a second propagation time measurement and a second plurality of OTDOA RSTD measurements from a second UE at a second time, determines at least one real-time difference between a pair of base stations based on the first and second propagation time measurements and the first and second pluralities of OTDOA RSTD measurements, wherein the pair of base stations is associated with the first and second pluralities of OTDOA RSTD measurements, receives a third plurality of OTDOA RSTD measurements from a third UE at a third time, and determines a position of the third UE based at least in part on the at least one real-time difference between the pair of base stations.

Systems, methods, and apparatus are provided for automated identification of open space in a wireless communications spectrum, by identifying sources of signal emission in the spectrum by automatically detecting signals, analyzing signals, comparing signal data to historical and reference data, creating corresponding signal profiles, and determining information about the open space based upon the measured and analyzed data in near real-time.

An observation satellite is used for obtaining information about electromagnetic energy emitted from the earth. The observation satellite orbits the earth in an orbit having an inclination larger than 90? and smaller than 270?. Further, the observation satellite comprises at least one receiving antenna, the at least one receiving antenna having a receiving pattern directed towards the earth, and suitable for receiving electromagnetic energy in the radio frequency range as the observation satellite is orbiting relative to the surface of the earth. The observation satellite also comprises a transmitter configured for at least one of: (i) retransmitting, to a relay spacecraft, the received electromagnetic energy, (ii) transmitting, to the relay spacecraft, information representing the received electromagnetic energy, and (iii) transmitting, to the relay spacecraft, information derived from the received electromagnetic energy. The invention also relates to systems and methods therefor.