Abstract: Embodiments of an improved assisted global positioning system (GPS) method and system are described. Wireless access points send assistance data to GPS receivers that are integrated into cellular chipsets and other chipsets. The access points may also act as fixed location references for differential GPS (DGPS) mobile stations. Errors caused by multipath travel of the GPS signals are reduced by using fixed location reference receivers.

Abstract: A system and method for determining whether a wireless device has transmitted one or more forged satellite measurements. An estimated location of the wireless device may be determined as a function of information from a cellular network. Acquisition assistance data may be determined for a first set of satellites as a function of the estimated location, the assistance data including an uncertainty window. If measured code phase information in the satellite measurements substantially correlates to the uncertainty window, then the wireless device may be transmitting forged satellite measurements.

Abstract: A control module interconnecting a transmitter portion and a signal receiver portion of a mobile device is provided. The control module monitors the transmitter portion of the mobile device and, based on the monitored condition, alters the mobile device to inhibit the ability of a transmission signal from a transmitter to interfere with the signal receiver portion, i.e., intelligent blanking. In other words, the control module may disable or modify the signal receiver portion when power on the transmitter portion exceeds a predetermined power threshold level. Alternatively the control module may force the transmitter portion to transmit at a reduced power level.

Abstract: Aspects of a method and system for Doppler estimation may include generating, in a GNSS receiver operating in a duty-cycle mode, a plurality of lag-m products that may be based on a plurality of correlation coefficients corresponding to one or more received signals, wherein the plurality of correlation coefficients may be generated during an active period of the duty-cycle mode of operation. A Doppler frequency may be estimated based on the plurality of lag-m products. The GNSS receiver may be compliant with one or more standards comprising GALILEO, GLONASS, IRNSS, and BEIDOU. The active period of the duty-cycle mode may be chosen arbitrarily from a range of 1% to 99%.

Abstract: A global navigation satellite system (GNSS) enabled mobile device may be operable to monitor and determine counts at which autoblank signals are asserted over time intervals corresponding to consecutive time windows during the RF interference mitigation process using autoblanking. The GNSS enabled mobile device may be operable to disable the generation of a blank signal when the count may be greater than a particular count threshold at the end of the time window. The GNSS enabled mobile device may be operable to enable the generation of a blank signal when the count may be less than or equal to a particular count threshold at the end of the time window. The blank signals may be used to blank the processing of the received GNSS signals.

Abstract: A direction finding antenna system for determining the relative bearing of a second aircraft from a first aircraft in conjunction with Distance Measuring Equipment (DME). The system includes a first antenna and a second antenna located on a top surface of the first aircraft, spaced apart along a first axis, as well as a third antenna and a fourth antenna located on a bottom surface of the first aircraft, spaced apart along a second axis orthogonal to the first axis. The system further includes a transmitting, receiving, and processing system coupled to the first, second, third, and fourth antennas, wherein the transmitting, receiving, and processing system is configured to transmit DME interrogations, receive DME replies, and process the DME replies to determine the relative bearing of the second aircraft from the first aircraft.

Abstract: Authentication of a signal, signalA, that is provided as having been received from a source at a first global location by comparing it to a signal that is received from the source at a second global location, signalB, where signalB contains an unknown signal that is unique to the source, and determining, that signalA contains the same unknown signal that is contained in signalB.

Abstract: A system and method for detecting one or more forged satellite measurements transmitted from a wireless device. Information may be transmitted to a wireless device, the information including a request that the wireless device provide a portion of a navigation data message from one or more satellites to a location determining system. The one or more satellite measurements and the portion of the navigation data message may be received from the wireless device. The navigation data message may be determined as a function of information from a reference network. The determined navigation data message may then be compared with the received navigation data message portion to thereby determine whether any of the one or more satellite measurements transmitted by the device have been forged.

Abstract: A radar apparatus having an integral ARPA function transmits at least two kinds of pulse signals, each of which has different pulselength, according to a specific transmission pattern and receives echoes of the transmitted pulse signal. The radar apparatus includes an echo data generator for generating display echo data for each range scale selected for on-screen presentation by using an echo signal obtained with each transmission pulselength, an ARPA processor for generating a single set of motion-related information on each tracked target to be superimposed on the display echo data by using echo signals obtained with the different pulselengths, a display output synthesizer for superimposing the motion-related information on each tracked target generated by the ARPA processor on the display echo data, and a display unit for displaying a superimposed picture produced by the display output synthesizer.

Abstract: Systems and methods are presented for passive location of transmitters in which two or more receivers time stamp received signals from target transmitters and the time stamped data for each target signal of interest is isolated to identify a peak power time of arrival for the signal at each transmitter from which differential scan observation values are derived, and for each signal of interest a line of position curve is computed based on the differential scan observation value and corresponding receiver locations, and for each signal of interest an estimated target transmitter location is determined based on an intersection of two corresponding line of position curves.

Abstract: In a multilateration system receivers are grouped into two groups. The first group is used to determine a position of a signal source, for example, an aircraft equipped with a SAR transponder. From the determined position, predicted time of arrival values are produced for the second group receivers. These are compared with the actual time of arrival values for the signals arriving at the second group receivers. A difference is determined and then the variation of that difference is determined as the aircraft travels in its track. The groupings are then varied and further variations determined. When the minimum variation is determined an alert is given that the second group has a receiver which is operating with a larger than desirable group time delay.

Abstract: A method of determining a filling level of a product contained in a tank, the method comprising generating and transmitting electromagnetic signals; propagating the transmitted electromagnetic signals towards a surface of the product contained in the tank; receiving echo signals resulting from reflections at impedance transitions encountered by the transmitted electromagnetic signals, including a surface echo signal resulting from reflection at a surface of the product; determining a position of a reference impedance transition using a reference echo signal resulting from reflection of the transmitted electromagnetic signals at the reference impedance transition; determining an update level located above the surface, based on the determined position of the reference impedance transition and a known position of the reference impedance transition; determining a disturbance echo profile using at least one of the echo signals resulting from reflection of the transmitted signals at at least one impedance transitio

Abstract: At least two receiver sets are provided. A data processor is in communication with the receiver sets, wherein the data processor tags position data and radio frequency emission data from the receiver sets. A data storage unit is in communication with the data processor and is at least capable of storing tagged data. A processing unit is capable of processing the tagged data. The processing unit defines a search grid within which to search for the source of the radio frequency emission. The processing unit motion compensates the tagged data separately for each point on the grid. The processing unit assigns a value to each grid point based on a phase coherence of the motion compensated data. The processing unit determines a location within the grid having a highest assigned value, thereby determining the source of the radio frequency emission.

Abstract: A phased array antenna system with two dimensional scanning includes a two dimensional array A of antenna elements A1,1 to A12,12 arranged in lines; each line is associated with a respective first rank corporate feed network 161 to 1612 having outputs 171,1 to 1712,12 connected to respective antenna elements A1,1 to A12,12 and inputs for variable relative phase input signals. These corporate feed networks each have first and second inputs A1/B1 to A12/B12 connected respectively to outputs 171 CD/1712CD to 171EF/1712EF of different second rank corporate feed networks 16CD and 16EF. The corporate feed networks 161 to 16EF convert input signals of variable relative phase into relatively greater numbers of output signals for a phased array.

Abstract: The positioning apparatus and position apparatus control method are able to efficiently receive useful signals without special circuitry.

Abstract: A system and method for determining the position and velocity of a plurality of vehicles relative to a host vehicle using GPS data. The method includes building a graph of the vehicles that define weighted baselines between each of the vehicles and the host vehicle and each of the vehicles where the weighted baselines define a geometric dilution of precision between the vehicles. The method then determines the optimal baseline between the host vehicle and each of the other vehicles using the weighted baselines based on the lowest geometric dilution of precision. The method then computes the relative position and velocity between all of the vehicles and the host vehicle using the optimal baselines.

Abstract: A radar device is mounted on a vehicle, for detecting an object, and includes: a transmitting unit for transmitting an electromagnetic wave as a transmitter signal; a receiving unit for receiving a reflected signal that is reflected from the object as a receiver signal; a signal processing unit for measuring a distance and a relative velocity between the vehicle and the object on the basis of a beat signal that is obtained by the transmitter signal and the receiver signal; and an interference detecting unit for detecting the interference signal from another radar device or a communication device on the basis of a signal intensity of the frequency range that is not used for measuring the distance to the object and the relative velocity of the object.

Abstract: A multi-antenna transmitting apparatus wherein a relatively simple selection procedure can be used to reconcile the data transmission rate and the received data quality. When a transport signal, which is required to have a higher quality than other signals, is to be transmitted, a vector multiplexing part (105) reduces the number of transport beams (i.e., reduces the number of unique paths used for transmission), and further gives a higher priority to a unique vector belonging to a large unique value and uses that unique vector to vector multiplex the transport signal, thereby forming a transport beam (i.e., gives a higher priority to a signal, which is required to have a high quality, and transmits that signal by use of a unique path having a large path gain).

Abstract: A method for tracking a satellite signal by a GPS includes the following steps. Data is continuously received from one of satellites by using tracking frequencies updated one by one based on an average phase difference of received data. Phase inversion points in the plurality of received data are interpreted. A time difference between each two adjacent phase inversion points among the phase inversion points is calculated. It is determined whether each time difference is an integral multiple of 20 ms. When each time difference is an integral multiple of 20 ms, 1-bit data is retrieved for every 20 ms from the satellite signal by taking a first phase inversion point among the plurality of phase inversion points as a starting point. Thus, a positioning speed is increased and a required positioning time is reduced by finding out a precise tracking frequency and a correct phase inversion point.

Abstract: Various techniques are provided for calibrating a frequency of a local clock using a satellite signal. In one example, a method of transferring frequency stability from a satellite to a device includes receiving a signal from the satellite. The method also includes determining a code phase from the satellite signal. The method further includes receiving aiding information. In addition, the method includes calibrating a frequency of a local clock of the device using the code phase and the aiding information to substantially synchronize the local clock frequency with a satellite clock frequency.