Abstract: The disclosed technology teaches testing an autonomous vehicle: shielding a GNSS receiving antenna of the vehicle from ambient GNSS signals while the vehicle is under test and supplanting the ambient GNSS signals with simulated GNSS signals. Testing includes using a GNSS signal generating system: receiving the ambient GNSS signals using an antenna of the system and determining a location and acceleration of the vehicle from the GNSS signals, accessing a model of an augmented environment that includes multi-pathing and obscuration of the GNSS signals along a test path, based on the determined location—generating the simulated GNSS signals to feed to the vehicle, in real time—simulating at least one constellation of GNSS satellite sources modified according to the augmented environment, based on the determined location, and feeding the simulated signals to a receiver in the vehicle, thereby supplanting ambient GNSS as the autonomous vehicle travels along the test path.

Abstract: Methods, systems, and devices for wireless communications are described. The method may include establishing a connection between the UE and a network node of a non-terrestrial network, identifying, based on a synchronization failure event and while the UE is in a connected mode in accordance with establishing the connection, that a location failure condition has occurred for the connection, and performing, at least in part in response to the location failure condition, one or more actions of a location failure recovery procedure to restore a synchronization associated with the connection.

Abstract: An ultra-low or very low frequency communication device composed of: a circuit unit operative to produce an alternating current; and a dipole antenna connected to receive the alternating current and to convert the alternating current into electromagnetic radiation. The antenna is composed of an unshielded radiating conductor and a shielded return conductor connected in series with the radiating conductor, and the return conductor is shielded by a Faraday shield such as a collisionless plasma column that surrounds the return conductor to prevent any electromagnetic radiation from the return conductor.

Abstract: The disclosure refers to a method for determining and storing surface conditions for a field, comprising: moving an agricultural machine having an earth-working roller system over a field, the earth-working roller system comprising an earth-working roller assembly; detecting sensor signals for an oscillating movement of the earth-working roller assembly; detecting position data for the movement of the earth-working roller system over the field; generating a digital surface map for the field indicative of position-dependent roughness and/or leveling information, the generating comprising assigning the sensor signals to the position data; and storing the digital surface map in a data storage device. Further, a system for determining and storing surface conditions for a field is provided.

Abstract: An exemplary method of calculating a position of a GNSS device (e.g., a GNSS rover device) comprises: at the GNSS device in an enhanced real-time kinematic (RTK) mode: receiving a first set of GNSS data corresponding to a first epoch; storing the first set of GNSS data in a buffer; receiving a second set of GNSS data corresponding to a second epoch that is after the first epoch; after receiving the second set of GNSS data, retrieving the first set of GNSS data from the buffer; and calculating the position of the GNSS device based on the retrieved first set of GNSS data and the second set of GNSS data.

Abstract: System and method for adjusting timing error in a mobile device. In the mobile device, a crystal oscillator (XO) is used by a system timer as the timing source. When the mobile device enters into a sleep mode, the system timer is set to time the duration of the sleep mode. During the sleep mode, a thermistor is used to measure and monitor the temperature changes of the XO. After the sleep mode is over, a processor in the mobile device determines the frequency changes of the XO based on the temperature changes of the XO. Based on the frequency changes of the XO, the processor determines the timing error that may have occurred when the system timer was timing the sleep mode and determines the actual duration of the sleep mode by adjusting the duration timed by the system timer based on the timing error.

Abstract: An electronic timepiece includes a radio wave receiver, a communication unit, a memory and a processor. The radio wave receiver receives radio waves from positioning satellites. The communication unit communicates with an external device. The memory stores a program and predicted positional information on the positioning satellites. Based on the program stored in the memory, the processor shifts the timepiece between a normal operation state and a power saving state in which operation of the timepiece is restricted, depending on a status of the timepiece. In response to an elapsed time from a valid period of the predicted positional information exceeding a predetermined reference time during the power saving state, the processor causes the communication unit to receive updated data of the predicted positional information and other information from the external device when shifting the timepiece from the power saving state to the normal operation state.

Abstract: The invention relates to a method for error evaluation in position determination, comprising time-synchronous recording of first and second position values, wherein the second position values are recorded by a different measuring method than the first position values; forming a first and a second trajectory (A, B) from the first and the second position values respectively; forming differential vectors (D) between first and second position values recorded at the same time; parallel-shifting the second trajectory (B) along a displacement vector (s) such that the amounts of the differential vectors (D) are minimized on average; evaluating the faultiness of the position determination on the basis of one or more amounts of the differential vectors (D) created as a consequence of the parallel shift.

Abstract: A building radar-camera system includes a camera configured to capture one or images, the one or more images including first locations within the one or more images of one or more points on a world-plane and a radar system configured to capture radar data indicating second locations on the world-plane of the one or more points. The system includes one or more processing circuits configured to receive a correspondence between the first locations and the second locations of the one or more points, generate a sphere-to-plane homography, the sphere-to-plane homography translating between points captured by the camera modeled on a unit-sphere and the world-plane based on the correspondence between the first locations and the second locations, and translate one or more additional points captured by the camera or captured by the radar system between the unit-sphere and the world-plane based on the sphere-to-plane homography.

Abstract: Satellite signal propagation delay variation can be compensated by transmitting ephemeris data of a satellite and cell measurement window specifications to a terminal, receiving an indication from the terminal that a cell measurement signal will arrive at the terminal outside of a time frame defined by the cell measurement window specifications, modifying the cell measurement window specifications based on a difference in propagation delay between a serving cell, which defines the cell measurement window specifications, and a neighboring cell, which transmits the cell measurement signal, so that the cell measurement signal will arrive at the terminal within the time frame defined by the cell measurement window specifications, the satellite providing communication with the terminal for at least one of the serving cell and the neighboring cell, and transmitting modified cell measurement window specifications to the terminal.

Abstract: The present disclosure provides methods and systems for locally suppressing interference in RF communications by satellites and related methods of using such systems. In some aspects, the interference suppression is performed by one or more small form factor satellites (e.g., CubeSats).

Abstract: A system for testing a global navigation satellite system (GNSS) receiver includes signal generators, antennas coupled to respective signal generators and having overlapping antenna radiation patterns, and processing circuitry. The signal generators generate respective test signals. Each of the test signals is a combination of multiple GNSS navigational signals which are generated using a set of ranging codes. The processing circuitry selects respective sets of ranging codes for the signal generators, such that the sets of ranging codes are separately insufficient to lock a GNSS receiver and are jointly sufficient to lock a GNSS receiver.

Abstract: A system and method for irrigation, and managing irrigation of, a property or landscape. The system may include an irrigation management server (“IMS”) with the information for an irrigation system. The system may access the irrigation system that has been input into the IMS as well as access a third party map that may display the irrigation system over the map. The system may provide for a user's GPS location to be accessed through and identify the location of the user with respect to the map and irrigation overlay. The system display may provide information regarding the landscape to a user. The system may allow for manipulation of the irrigation system while overlaid on the map by the creation and manipulation of zones within the irrigation system as well as the creation and manipulation of other commands, including watering times and watering duration.

Abstract: A system and method for determining a GNSS receiver position includes receiving a first and a second set of satellite observations; determining a first and second ambiguity set associated with a first and second transformation respectively; determining cross-validated ambiguities between the first and second ambiguity sets; and determining the GNSS receiver position based on at least one of the first or second ambiguity sets.

Abstract: A system provided for use with a lawn mower includes a processor in communication with the lawn mower. The processor is configured to acquire geographic location data of the lawn mower and mapping data for the lawn mower as the lawn mower operates on the plot of land. The processor is configured to acquire performance data of the lawn mower as the lawn mower operates on the plot of land according to a first path and generate a map of the plot of land at least partially based on the geographic location data and the mapping data. The processor is configured to determine an operational efficiency of the lawn mower according to the first path and determine a second path for the lawn mower that increases the operational efficiency of the lawn mower for operating on the plot of land.

Abstract: The present teaching relates to apparatus, method, medium, and implementations for initiating sensor calibration. A first GPS signal is received by a GPS receiver residing in an ego vehicle and is used to determine a first geo-position of the ego vehicle. A GPS related signal transmitted by a fiducial marker is received and is used to obtain a second geo-position of the fiducial marker. A distance between the ego vehicle and the fiducial marker is determined based on the first and second geo-positions and is used to determine whether to initiate calibration of one or more sensors using the fiducial marker.

Abstract: An apparatus for vector tracking a plurality of satellite signals received by a Global Navigation Satellite System (GNSS) receiver from a plurality of satellites and a method for use thereof.

Abstract: Among other things, a communication system comprising remote units, a reference timing source, a controller, a controller clock, and a remote unit clock. The remote units exchange radio frequency (RF) signals with mobile devices. The reference timing source is synchronized with a coordinated universal time (UTC) or a Global Positioning System (GPS). The controller clock is synchronized with the reference timing source and provides timing information to the controller. The remote unit clock is synchronized with the controller clock and provides timing information to a remote unit. The controller and the remote unit are configured to transmit time stamp messages to synchronize the controller clock and the remote unit clock, by avoiding contention between time stamp transmissions and baseband data transmissions or between time stamp transmissions of different remote units to the controller.

Abstract: A wireless seismic data acquisition unit with a wireless receiver providing access to a common remote time reference shared by wireless seismic data acquisition units in a seismic system. The receiver can replicate local version of remote time epoch to which a seismic sensor analog-to-digital converter is synchronized. The receiver can replicate local version of remote common time reference to time stamp local node events. The receiver can be placed in a low power, non-operational state over periods of time during which the unit continues to record seismic data, thus conserving unit battery power. The system corrects the local time clock based on intermittent access to the common remote time reference. The system corrects the local time clock via a voltage controlled oscillator to account for environmentally induced timing errors.

Abstract: A system for generating a 3D reflective surface map includes a positioning system, one or more antennas co-located with the positioning system, and a processing system. The positioning system calculates a position estimate. The one or more antennas co-located with the positioning system are configured to receive at least one reflected global navigation satellite system (GNSS) signal associated with a respective GNSS satellite and wherein a pseudo-range to the GNSS satellite is determined based on the reflected GNSS signal. The processing system is configured to receive the position estimate and the pseudo-ranges calculated with respect to each reflected GNSS signal, wherein the processing system maps a reflective surface based on the calculated pseudo-range provided by the reflected GNSS signals, the position estimate, angle-of-arrival of each reflected GNSS signal, and known satellite location of each respective GNSS satellite.

Abstract: Methods and devices for puncturing of a polar code in a wireless network, wherein nested puncturing sets are determined based on a puncturing order which is determined based on a reliability order of information bit channels, so that only one index sequence needs to be stored for both the determination of the information set and the determination of the punctured set and so that puncturing does not require to adjust the information set at error prone indexes corresponding to puncturing indexes. The puncturing order might start with indexes corresponding to high reliability bit channels or to low reliability bit channels.

Abstract: A time synchronization method that is capable of selecting whether synchronization, by a timepiece unit that generates a time signal synchronized with a standard time and outputs it to an exterior, with the time is performed by time information obtained by receiving a radio wave including information relating to the time, or is performed by means of a holdover performed using a clock signal from an internal or external clock source. A schedule having a first time period in which the above-mentioned time information is used, and a second time period by means of the holdover is determined according to temporal reception characteristics of the radio wave at a reception location of the radio wave, and according to the schedule, supplying the timepiece unit with the time information or supplying the timepiece unit with the clock signal from the internal or external clock source.

Abstract: A personal locator beacon system has a personal locator beacon and a biometrics monitor. The personal locator beacon includes a first microprocessor, a first global positioning subsystem coupled to the first microprocessor, a first low energy transceiver coupled to the first microprocessor, and a first low energy antennae coupled to the first low energy transceiver. The biometrics monitor includes a second microprocessor, a second low energy transceiver coupled to the second microprocessor, a second low energy antennae coupled to the second low energy transceiver, and one or more nanosensors.

Abstract: A location server device includes a memory circuitry, a processor circuitry, and an interface. The location server device is configured to communicate, via the interface, with one or more positioning units configured to communicate with one or more electronic devices one or more first positioning signals at a first frequency. The processor circuitry is configured to select at least one of the one or more positioning units based on detecting a trigger event. The interface is configured to transmit, to the at least one selected positioning unit, an activation signal. The activation signal indicates to the at least one selected positioning unit to activate transmission of one or more second positioning signals at a second frequency that is different from the first frequency.

Abstract: A Global Navigation Satellite System (GNSS) receiver demodulates code shift keying (CSK) data utilizing a binary search. The GNSS receiver receives a signal including a pseudorandom noise (PRN) code modulated by code shift keying (CSK) to represent a symbol (i.e., CSK modulated symbol). The GNSS receiver maintains a plurality of receiver codes each representing a different shift in chips to the PRN code. The GNSS receiver performs a linear combination of portions of the receiver codes. In an embodiment, the GNSS receiver compares correlation power level value for respective portions of the receiver codes to demodulate the CSK data. In a further embodiment, the GNSS receiver compares the correlation power level values for portions of receiver codes with power detection threshold values to demodulate the CSK data. In a further embodiment, the GNSS receiver utilizes signs of the correlation power level values to demodulate the CSK data.

Abstract: An illustrated embodiment disclosed herein is a method including correlating, by an endpoint, a first frame and a second frame with a plurality of hypotheses, detecting, by the endpoint, for each correlation of the first frame, a first metric and, for each correlation of the second frame, a second metric, identifying, by the endpoint, a first subset of hypotheses based on the first metric and a second subset of hypotheses based on the second metric, identifying, by the endpoint, pairs of hypotheses, each pair including a first hypothesis from the first subset and a second hypothesis from the second subset. The first hypothesis is same or within a predetermined distance of the second hypothesis. The method includes selecting, by the endpoint and from the pairs of hypotheses, a hypothesis based on the second metric and selecting, by the endpoint, a channel for transmission at which the hypothesis is selected.

Abstract: A high-precision real-time satellite positioning method comprises: establishing a polygonal satellite positioning receiver array comprising a plurality of satellite positioning receiving mechanisms; transmitting, by the satellite positioning receiving mechanisms, and to a processor module, respective IDs and observation coordinates; computing, by the processor module, a physical geometric pattern and an observation geometric pattern; comparing the physical geometric pattern and the observation geometric pattern to extract an offset vector caused by an error, and to generate an offset vector function library; and subtracting the offset vector from an observation value of a phase center of antennas of the satellite positioning receivers to obtain a corrected satellite positioning value.

Abstract: A fiber optic gyroscope inputs laser light into opposing ends of a fiber optic coil and detects light at the same ends of the optical fiber. A pulse-per-second signal is generated by determining the phase difference between the two opposing laser light signals, and generating electrical pulses based on this detected phase difference. The fiber optic gyroscope may become a source of one or more PPS signals used by a vehicle.

Abstract: A Grandmaster clock is presented. The Grandmaster clock has a GNSS interface receiving GNSS time sync data, a Real Time Clock (RTC) with a crystal oscillator, one or more communication interfaces exchanging data with clock correction sources, and a clock correction host. The clock correction host computes clock drift based on the GNSS time sync data and the data from clock correction sources, generating adjusted clock data, and writing the adjusted clock data to the RTC from different locations. The Grandmaster clock may be in a vehicle.

Abstract: In one implementation, a method includes receiving a number of instances of a message that includes a self-reported position of a transmitter of the message from a corresponding number of satellite-based receivers that each received an RF transmission of an instance of the message. The method also includes determining the number of satellite-based receivers that received an instance of the message and selecting a validation technique based on the number of satellite-based receivers that received an instance of the message. If the number of satellite-based receivers that received an instance of the message is one, a propagation-based validation technique is selected. The method further includes determining a measure of the likelihood that the self-reported position of the transmitter is valid using the selected validation technique, and transmitting an indication of the measure of the likelihood that the self-reported position is valid.

Abstract: A method is disclosed for generating routes in an area covered by an electronic map. The map comprises a plurality of segments representing navigable segments of a navigable network in the area covered by the electronic map. A first route is generated between a first location and a second location in the area. A central portion of the first route is defined, wherein the central portion has an extent along the first route that is determined based on a distance between the first and second locations. The relative extent of the central portion along the first route is inversely related to the distance between the first and second locations. One or more navigable segments forming the defined central portion along the first route are identified, and a cost penalty applied to the identified navigable segment(s) so as to make the segment(s) less favourable when a route is generated through the navigable network. An alternative route is then generated between the first location and second location.

Abstract: A satellite-based positioning system (SPS) signal processing technique re-samples a received series of PRN sequences from an SPS satellite to align them with a nominal sampling rate for a corresponding series of perfect reference PRN replica sequences.

Abstract: A timing signal generation device includes: an output terminal that outputs a standard signal; a first standard signal generation unit that generates a first standard signal based on a reference signal input from outside; a second standard signal generation unit that generates a second standard signal based on a signal output from an oscillator; and a control unit that switches the standard signal output from the output terminal from the first standard signal to the second standard signal based on prior information indicating that accuracy of the reference signal deteriorates.

Abstract: Apparatuses and methods of manufacturing same, systems, and methods are described for combining received and correlated Global Navigation Satellite System (GNSS) signals and using the combined signal for improving GNSS reception in, inter alia, challenging environments. In one aspect, a first correlated GNSS signal and a second correlated GNSS signal are stored and then combined, and the combined signal is used to adjust reception of the first GNSS signal and/or the second GNSS signal. If the first and second correlated GNSS signals are stored by unequal time periods, time periods of one or both are added together until the total added first correlated GNSS signal is the same length of time as the total added second correlated GNSS signal. In order to properly combine the GNSS signals, gain/balancing factor(s) may be applied, the polarity of one or both may be flipped, etc.

Abstract: Improved methods and systems for position acquisition and/or monitoring are disclosed. The position acquisition and/or monitoring can be performed with improved intelligence so that data acquisition, transmission and/or processing is reduced. As a result, the position acquisition and/or monitoring is able to be performed in a power efficient manner.

Abstract: A global navigation satellite system (GNSS) antenna sharing receiver (GNSSASR) for sharing a GNSS antenna with one or more secondary GNSS receivers is provided. The GNSSASR includes an input radio frequency (RF) port for receiving a GNSS signal from the GNSS antenna, one or more output RF ports for transmitting the GNSS signal to the secondary GNSS receivers, a coupler for reducing attenuation in the GNSS signal transmitted to the secondary GNSS receivers, a power supply circuit for supplying a direct current (DC) voltage with reduced loss to the GNSS antenna based on availability of a secondary GNSS receiver, and a current monitoring circuit for monitoring DC flow to the GNSS antenna from the power supply circuit, limiting an increase in the DC flow due to a fault in the GNSS antenna, and indicating a fault in the GNSS antenna to the GNSSASR and the secondary GNSS receivers.

Abstract: An interferometric sensor and related methods are provided, with a sensing element whereby a measurand induces a relative phase shift between two waves, at least one detector measuring an interference signal between the two waves, and further including a phase shift detection unit having as input the interference signal and determining a first measure representative of the principal value of the relative phase shift, and a contrast detection unit having as input the interference signal for determining a second measure representative of the cross-correlation between the two waves, and a further a processing unit for converting the first and second measures to a measurand value.

Abstract: A position-determining apparatus, such as a GPS receiver, determines the position of the mobile device based on the time of flight of a transmitted probe signal using a method in which sections of the received signal is classified into two or more categories and accumulated according to categories before being used to compute the correlations familiar in the context of a matched filter. Using the method of the present invention to compute the correlations, and optionally applying additional time-saving techniques described herein, a position determination is achieved using arithmetic operations that are significantly reduced from that required in prior art methods to compute the correlations. The reduced number of arithmetic operations can reduce significantly the power consumption required of a device carrying out a method of the present invention, and thereby realizing a significant advantage.

Abstract: A positioning apparatus includes one or more processors; and one or more memories storing instructions that cause the processors to perform the following. Performing first receiving to receive one piece of orbit information showing a position of one positioning satellite and which attempts to receive another piece of orbit information showing a position of another positioning satellite. Performing first obtaining to obtain the another piece of orbit information (i) when receiving the another piece of orbit information is attempted but the another piece of orbit information is not received and the another piece of orbit information is received by the another positioning apparatus or (ii) when, the another piece of orbit information received by the another positioning apparatus is newer than that received in the first receiving. Performing positioning processing based on the one piece of received orbit information and the another piece of obtained orbit information.

Abstract: A method for testing a communication between a mobile device and a satellite system is described, wherein testing signals are generated by using a signal generation unit, said testing signals simulating satellite signals of at least one satellite of said satellite system. Further, said testing signals are received by a device under test being used as said mobile device. Said testing signals simulate at least one of a changing satellite signal strength, a changing satellite signal quality, a changing position of said satellite and more than one satellite signal in parallel. Further, said testing signals simulate a changing position of said mobile device. In addition, a testing system for testing a communication between a mobile device and a satellite system is described.

Abstract: Multicast expert system information dissemination systems and methods making use of artificial intelligence are provided. The systems and methods include a wireless device for receiving RF multicast information messages from a content provider wherein said information is descriptive of objects potentially of interest to users of the device. Received multicast messages may include information parameters about objects of potentially interest to the user. The wireless device also includes a knowledge base prestored in the wireless device descriptive of the user's level of interest in various objects. Artificial intelligence expert system control is used to evaluate a combination of the user's level of interest in the object information and distance from the user to the location where the object may be obtained. The artificial intelligence expert system derives a user advisory action index. In one embodiment the artificial intelligence may be implemented using fuzzy logic inference engine apparatus.

Abstract: The application is generally directed to transmitting and receiving signals in a fashion that can mask the presence of the signals by including timing information in the signals using artifacts in a carrier signal. For example, one embodiment includes a method of transmitting a signal in a way to mask the presence of the signal or to reduce the ability of external entities to extract data from the signal. The method includes accessing a data signal. A phase of the data signal is correlated to a phase of a substantially continuous carrier signal carrying the data signal. The substantially continuous carrier signal carrying the data signal with the phase of the data signal correlated to the phase of the substantially continuous carrier signal is transmitted to a receiver, such that the data signal can be extracted by using phase correlation between the data signal and the substantially continuous carrier signal.

Abstract: A system and method of setting a clock at a vehicle, including: operating a vehicle clock installed in a vehicle; receiving an external time signal via wireless communications, wherein the external time signal is a wireless communications signal that includes a time value; determining whether a predetermined amount of time has passed since a most-recent clock update; when it is determined that a predetermined amount of time has passed since the most-recent vehicle clock update, then carrying out the following steps: (i) calculating a measured drift and a drift limit; (ii) determining whether the measured drift is less than the drift limit; and (iii) when it is determined that the measured drift is less than the drift limit, then setting the vehicle clock to the time value included in the received external time signal.

Abstract: A disciplined clock provides a disciplined time and a disciplined frequency synchronous with a reference clock. The disciplined clock includes: a time receiver to: receive a common view signal from the common view clock; and produce a receiver timing signal; a local clock to: receive a frequency correction; and produce a local timing signal; a time interval counter to: receive the receiver timing signal from the time receiver; receive the local timing signal from the lock clock; and determine a time difference between the receiver timing signal and the local timing signal; and a controller to: receive the time difference from the time interval counter; and communicate the frequency correction, based on the time difference, to the local clock.

Abstract: Methods, systems, and apparatus for detecting poor Doppler measurements results in GNSS navigation, in one aspect, a method including: calculating a first Doppler shift value, wherein the first Doppler shift value is based on movement of a Global Navigation Satellite System (GNSS) receiver and calculated according to a Doppler measurement result; calculating a second Doppler shift value, wherein the second Doppler shift value is based on movement of the GNSS receiver and calculated according to a projection of velocity of the GNSS receiver on a line of sight (LOS) vector; comparing the first Doppler shift value with the second Doppler shift value to check an accuracy of the Doppler measurement result; and determining at least a direction of movement of the GNSS receiver in accordance with the checked accuracy of the Doppler measurement result.

Abstract: Technique for improving efficiency of on-chip antennas, comprising placing each antenna on an individual area on the chip, defined by channels provided in the chip before or after placing the antenna(s). The channels may be metallized. Frequency of a radiating antenna element may be locked by wireless injection locking using a locked subharmonic frequency.

Abstract: Described herein are techniques for determining a location of a device. In an example, a group of access points may be selected. Time-of-flight (ToF) measurements relative to the device may be received from each of the access points in the group. A respective distance of the device from each access point may be determined using the ToF measurements and a baseToF value. Location coordinates of the device and a new baseToF value may be determined based on the determined distances and the location coordinates of each access point in the group.

Abstract: A received Direct Sequence Spread Spectrum DSSS signal is processed by performing DSSS acquisition to obtain estimates of a frequency offset and a spreading code phase, sequentially obtaining, for each one of a plurality of segments of a received DSSS signal, a correlation function between the DSSS signal segment and a replica of a spreading code by using a Time and Frequency Transform based correlation method, the estimated frequency and the spreading code phase, and performing DSSS carrier tracking by tracking the phase of a correlation peak in the obtained correlation functions, and applying phase corrections to the obtained correlation functions to provide fine Doppler compensation. The time and frequency transform based correlation method involves, for each segment of the received DSSS signal, obtaining a plurality of samples and transforming the samples from the time domain to the frequency domain.

Abstract: A wireless seismic data acquisition unit with a wireless receiver providing access to a common remote time reference shared by wireless seismic data acquisition units in a seismic system. The receiver can replicate local version of remote time epoch to which a seismic sensor analog-to-digital converter is synchronized. The receiver can replicate local version of remote common time reference to time stamp local node events. The receiver can be placed in a low power, non-operational state over periods of time during which the unit continues to record seismic data, thus conserving unit battery power. The system corrects the local time clock based on intermittent access to the common remote time reference. The system corrects the local time clock via a voltage controlled oscillator to account for environmentally induced timing errors. The system provides a more stable method of correcting drift in the local time clock.

Abstract: A receiving device according to the present invention includes: a search range control unit that determines, for a reception signal including a plurality of wireless signals partially overlapping on at least one of a time axis and a frequency axis and received by a moving object, a search range for the plurality of wireless signals in a search space including the time axis and the frequency axis based on information on position and velocity of the moving object; a time frequency detection unit that generates information on time and frequency at which a wireless frame included in each of the plurality of wireless signals is received in the search range for the reception signal determined by the search range control unit; and a detection unit that demodulates the reception signal to acquire the wireless frame based on the information on time and frequency generated by the time frequency detection unit.