Abstract: A system and method for determining the location of wireless sensors are disclosed. The system may generally include a plurality of wireless sensor nodes communicatively coupled to a plurality of sensing devices. Additionally, the system may include a paging device configured to wirelessly transmit a page command to at least one of the wireless sensor nodes. Further, the paging device may receive a position indicator as a text string indicating a location of at least one of the plurality of wireless sensor nodes.

Abstract: In a method for ascertaining whether a target object can be driven over by the controlled motor vehicle, with the aid of frequency-modulated radar signals of a radar sensor, amplitude ratios between received radar signals reflected from the target object are utilized, the received radar signals corresponding to signals which have been transmitted in different frequency ranges. Based on the amplitude ratios, an occurrence of interference between (i) a first radar signal propagation path between the radar sensor and the target object and (ii) a second propagation path with additional reflection from a road is detected, and based on the detection of an occurrence of interference it is ascertained whether the object can be driven over.

Abstract: An unmanned aerial system (UAS) position reporting system may include an air traffic control reporting system (ATC-RS) coupled with a ground control station (GCS) of an unmanned aerial system. The ATC-RS may include an automatic dependent surveillance broadcast (ADS-B) and traffic information services broadcast (TIS-B) transceiver and one or more telecommunications modems. The ATC-RS may be adapted to receive position data of the UAS in an airspace from the GCS and to selectively communicate the position of the UAS in the airspace to a civilian air traffic control center (ATC), to a military command and control (C2) communication center, or to both the civilian ATC and the military C2 communication center through the ADS-B and TIS-B transceiver. The ATC-RS may also be adapted to display the position of the UAS in the airspace on a display screen coupled with the ATC-RS.

Abstract: A radar receiver has plural antenna system processors each for performing coherent integration on the basis of correlation values between a reception signal and a transmission signal using correction amounts for phase variations corresponding to plural Doppler frequencies, plural correlation matrix generators for generating, for each of the plural different Doppler frequencies, correlation matrices which are pieces of phase difference information relating to an arrangement of reception antennas on the basis of sets of outputs of the coherent integration, respectively, an adder for adding together outputs of the plural correlation matrix generators, and an incoming direction estimator for estimating an incoming direction of reflection waves on the basis of outputs of the adder.

Abstract: The location of a transmitter can be determined by accurately measuring the elapsed time that it takes for a signal to propagate from a transmission source to a plurality of disparate receivers of a known location. By comparing the received transmitted signal to reference signal a range between each receiver and the transmitter can be determined. By intersecting the spheres defined by each range an accurate location of the transmitter can be obtained.

Abstract: Techniques for positioning access points and terminals in WLANs and other wireless networks are described. For access point positioning, measurements are obtained for at least one access point in a WLAN. The measurements may be based on transmission sequences (e.g., beacon frames) transmitted periodically by each access point. The measurements may be made by multiple terminals at different locations or a single mobile terminal at different locations. The location of each access point is determined based on the measurements and known locations of the terminal(s). For terminal positioning, measurements for at least one access point in a WLAN are obtained. The location of the terminal is determined based on the measurements and known location of each access point. The measurements may be round trip time (RTT) measurements, observed time difference (OTD) measurements, time of arrival (TOA) measurements, signal strength measurements, signal quality measurements, etc.

Abstract: A method for Link 16-based geolocation of hostile jammers comprising the steps of collecting jamming noise I/Q samples at a plurality of locations, determining the relative time delay of reception between two or more of the locations, determining the first derivative of the time delay of reception between the two or more locations, and using the results calculated in the preceding step to determine the position of the hostile jammers.

Abstract: A method of using a non-GPS-derived technique to estimate the location of an Assisted-GPS-enabled wireless terminal for the purposes of generating location-specific assistance data for the wireless terminal is disclosed. The wireless terminal then uses the assistance data to acquire and process one or more GPS signals and to derive information that is probative of the wireless terminal's location. The GPS-derived location information is then combined with non-GPS-derived location to form an estimate of the location of the wireless terminal that is better than can be derived from either alone. This combination of GPS-derived and non-GPS techniques is particularly useful when the wireless terminal can only acquire one or two GPS signals because it is not possible to determine the location of the wireless terminal with only two GPS signals alone.

Abstract: A neighborhood creating device includes: a memory; and one or more processors that execute a procedure in the memory, the procedure including a position acquiring process that acquires position information representing a position of a mobile object; a data creating process that creates mobile object data representing a condition associated with a movable range of the mobile object based on the position information; a data acquiring process that acquires obstacle data representing a condition associated with a place through which the mobile object is not able to move; and an information creating process that creates neighborhood information satisfying both conditions represented by the mobile object data and the obstacle data and continuously representing a movable range of the mobile object around the mobile object.

Abstract: A method and a system for storing a constant path loss exponent corresponding to free space; transmitting a signal; receiving the signal via a rake receiver of a user device; identifying a maximum received signal strength based on a signal strength associated with the signal relative to fingers of the rake receiver; storing a current maximum received signal strength value; determining whether the current maximum received signal strength value is a first maximum received signal strength value; calculating a current indoor position of the user device based on the constant path loss exponent and the current maximum received signal strength value when a determination is that the current maximum received signal strength value is the first maximum received signal strength value; and outputting the current indoor position.

Abstract: A method is disclosed for merging detection information produced by various sensors of a detection system formed by a passive radar system including various bistatic bases and by an external sensor. The method includes two processing phases. During the first phase, for each bistatic base of the passive radar bistatic plots produced by that bistatic base are first merged with bistatic plots produced on the basis of plots transmitted by the external sensor and projected into the bistatic base concerned. Then, by associating all the bistatic bases, bistatic tracking is applied to the merged bistatic plots and unmerged bistatic plots coming from the external sensor. During the second phase a cartesian tracking is generated on the basis of bistatic plots that contributed to forming the bistatic tracks.

Abstract: A system including a first wireless device and a second wireless network device. The first wireless network device is configured to transmit a data frame a first number of times, wherein the first number of times is determined based on a timing resolution associated with the first wireless network device, receive a respective acknowledgement frame in response to each transmission of the data frame, determine an accumulated delay period corresponding to a total time between each transmission of the data frame and reception of the respective acknowledgement frame, and calculate a distance between the first wireless network device and the second wireless network device based on the accumulated delay period and the first number of times. The second wireless network device is configured to receive each transmission of the data frame and transmit the respective acknowledgement frame in response to each transmission of the data frame.

Abstract: A wireless ranging system for determining a range of a remote wireless device may include a wireless transmitter and a wireless receiver. The wireless ranging system may also include a ranging controller to cooperate with the wireless transmitter and receiver to generate a multi-carrier base waveform, transmit a sounder waveform to the remote wireless device including concatenated copies of the multi-carrier base waveform, and receive a return waveform from the remote wireless device in response to the sounder waveform. The ranging controller may also generate time domain samples from the return waveform, convert the time domain samples into frequency domain data, and process the frequency domain data to determine the range of the remote wireless device.

Abstract: A method of operation of a mobile communication system includes: receiving a base carrier frequency signal from a cell tower location; generating a power spectral density from the base carrier frequency signal; measuring a Rician K factor from the power spectral density; estimating a line-of-sight Doppler frequency based on the base carrier frequency signal; determining the cell tower location based on the Rician K factor; and activating a handover decision handler based on the cell tower location.

Abstract: In a vehicle inclination detecting device, a receiving unit includes a switching unit for alternately switching between a received signal from a first receiving antenna and a received signal from a second receiving antenna to alternately output the received signals to an orthogonal detector. The orthogonal detector carries out orthogonal detection on each of the two received signals from the switching unit and an oscillating signal from an oscillator by using an identical line.

Abstract: Provided are a device and a method that can classify an incoming wave and can correctly distinguish the position of an originating device, even in a multipath environment. A principal vertically polarized wave arrival direction sensing unit (104-1) and a principal horizontally polarized wave arrival direction sensing unit (104-2) respectively sense the arrival direction of a principal wave by sensing the arrival direction in which the maximum reception level is obtained. An incoming wave classifying decision unit (108) determines that a direct wave has arrived when the difference between the principal wave arrival direction sensed by the principal vertically polarized wave arrival direction sensing unit (104-1) and the principal wave arrival direction sensed by the principal horizontally polarized wave arrival direction sensing unit (104-2) is within a prescribed threshold value, and determines that a direct wave has not arrived when the difference is greater than the threshold value.

Abstract: A system and method is provided for processing communication signals in a wireless personal area network (WPAN) using a transceiver comprising a first transmitter and a first receiver operable to transmit and receive signals using a first transmission protocol and a second transmitter operable to transmit signals using a second transmission protocol. In various embodiments, the first receiver is used to receive a first signal that was transmitted using the first communication protocol and the second transmitter is used to transmit a second signal using the second transmission protocol in response to receipt of the first signal. The second signal is then processed to determine the location of the object. In some embodiments, the first transmission protocol is compliant with an Institute of Electrical and Electronics Engineers 802.15.4 transmission protocol and the second transmission protocol is compliant with an Ultra-Wide Band (UWB) protocol.

Abstract: A system and method for locating mobile stations in a wireless communication system such as a cellular system based on at least one received wireless signal and a database of geographical information.

Abstract: Active RFID technologies are used to tag assets and people within buildings or open areas, such as parking lots or military bases; and to identify, preferably within a few meters, the real-time location (RTL) of the tag, i.e. to create a real-time location system, known as an RTLS. A novel and complex algorithm is provided that combines signal strength computations with factors that incorporate physical realities, such as walls and floors, to determine a tag's real-time location more accurately.

Abstract: Methods and architecture systems for controlling vehicle systems are disclosed. In one embodiment, a method of remotely controlling a vehicle includes estimating a position of the vehicle. A position estimation algorithm may estimate the position of the vehicle. A position data packet received from the vehicle may be used to update the estimated position of the vehicle. A display device may display a virtual representation of the vehicle based on the updated estimated position of the vehicle. Command signals may be transmitted to the vehicle based on the displayed virtual representation of the vehicle.

Abstract: A system for sensing aircraft and other objects uses bistatic radar with spread-spectrum signals transmitted from remotely located sources such as aircraft flying at very high altitudes or from a satellite constellation. A bistatic spread spectrum radar system using a satellite constellation can be integrated with a communications system and/or with a system using long baseline radar interferometry to validate the digital terrain elevation database. The reliability and safety of TCAS and ADS-B are improved by using the signals transmitted from a TCAS or ADS-B unit as a radar transmitter with a receiver used to receive reflections. Aircraft and other objects using spread spectrum radar are detected by using two separate receiving systems. Cross-Correlation between the outputs of the two receiving systems reveals whether a noise signal is produced by the receiving systems themselves or is coming from the outside.

Abstract: A first wireless device including a control module and a transmitter. The control module is configured to estimate a first path loss between the first wireless device and a second wireless device, estimate a second path loss between the first wireless device and the second wireless device, generate an absolute value of a difference between the first path loss and the second path loss, and compare the absolute value of the difference between the first path loss and the second path loss to a predetermined threshold. The transmitter is configured to transmit a radio frequency signal at the first minimum transmit power in response to the absolute value of the difference being less than or equal to the predetermined threshold, and transmit the radio frequency signal at a second minimum transmit power in response to the absolute value being greater than the predetermined threshold.

Abstract: An RF transceiver of a first network device respectively receives first, second, and third coordinates of second, third, and fourth network devices. A control module determines first, second, and third delay periods respectively corresponding to transmissions between first and second, first and third, and first and fourth network devices. The control module determines first, second, and third distances between the first and second, first and third, and first and fourth network devices respectively based on the first, second, and third delay periods. The control module determines a location of the first network device based on the first, second, and third distances and the first, second, and third coordinates.

Abstract: A method and a navigation device are disclosed for sharing at least one location message with at least one other device. The navigation device includes a receiver to determine a signal strength of a traffic message channel at a location, a memory to store information representing the signal strength of a traffic message channel, and at least one processor to correlate the information stored in memory to compile a traffic message channel resource and select a traffic message channel based on the traffic message channel resource and a location associated with a navigation device. The method includes determining a signal strength of a traffic message channel at a location, storing information representing the signal strength of a traffic message channel, correlating the information stored in memory to compile a traffic message channel resource, and selecting a traffic message channel based on the traffic message channel resource and a location associated with a navigation device.

Abstract: A method for generating electromagnetic waves in the ELF/ULF comprising the steps of using a ground-based Horizontal Electric Dipole (HED) antenna to send electromagnetic pulses upwardly in the E-region of the ionosphere to form an oscillatory or pulsed electric field; allowing said pulsed electric field to interact with magnetized plasma of the lower ionosphere to generate a pulsed horizontal and vertical current which have associated Horizontal and Vertical Electric Dipole moment; and allowing them to radiate.

Abstract: Systems and methods for mapping a structure detect wireless signals, including at least one multipath signal that has experienced at least one reflection against a portion of the structure prior to the detection. The wireless signals are analyzed to estimate reflection points for the multipath signal(s), and a map of at least the portion of the structure is generated based on the estimated reflection points.

Abstract: A method is disclosed for merging detection information produced by various sensors of a detection system formed by a passive radar system including various bistatic bases and by an external sensor. The method includes two processing phases. During the first phase, for each bistatic base of the passive radar bistatic plots produced by that bistatic base are first merged with bistatic plots produced on the basis of plots transmitted by the external sensor and projected into the bistatic base concerned. Then, by associating all the bistatic bases, bistatic tracking is applied to the merged bistatic plots and unmerged bistatic plots coming from the external sensor. During the second phase a cartesian tracking is generated on the basis of bistatic plots that contributed to forming the bistatic tracks.

Abstract: A radio communication apparatus for performing radio communication with a terminal apparatus, including: a calculation unit which calculates first and second propagation distances indicating path lengths of first and second paths respectively; a decision unit which determines whether the first and second received waves are reflected waves or direct waves, respectively, based on the first and second propagation distances, and outputs a first or second terminal-reflection point distance on determining the first or second received wave as the reflected wave, or outputs the first or second propagation distance on determining the first or second received wave as the direct wave; and a position measurement unit which measures the position of the terminal apparatus based on the first or second terminal-reflection point distance, or the first or second propagation distance.

Abstract: Estimating a current location of a receiver in a MediaFLO™ (Forward Link Only) mobile multimedia multicast system comprises receiving digital signals comprising a MediaFLO™ superframe comprising orthogonal frequency division multiplexing (OFDM) symbols; performing slot 3 processing of each medium access control (MAC) time unit of a data channel to identify a transmitter identity (TxID) of each transmitter; identifying corresponding geographical coordinates of each TxID; regenerating the digital signals for each of the transmitters using a local-area differentiator (LID) and a wide-area differentiator (WID) of the transmitters; dividing the digital signals by the corresponding regenerated transmitted signal to obtain channel estimates between the receiver and the corresponding transmitters; detecting a first peak in the channel estimates to determine a distance between the receiver and the corresponding transmitters; calculating a time difference of arrival of the digital signals; and estimating a current loca

Abstract: A method of locating a transmitter is disclosed. A communications link is established between multiple receiving stations and a control station, and used with a calibration signal to calibrate out the time delay of the communications link. A radiated signal from an unknown transmitter is received at a receiving station and sent to the control station over the communications link. The time of arrival is recorded. Upon receiving a user input, the communication link switches from transmitting the received radiated signal to transmitting the calibration signal. The start of calibration signal is timed to begin at the same time across all of the receiving stations. The communication link time delay for each link is calculated by subtracting the start time from the received time, and the communication link time delay is subtracted from the received time recorded for the radiated signal. TDOA calculations are made to locate the transmitter.

Abstract: A signal-of-opportunity location device (SOLD) that may be situated in a complex radio propagation environment with multiple RF signal obstructions receives RF signals from a distant transmitter. The RF signals from the distant transmitter interact with obstructions in the propagation environment local to the SOLD. The local obstructions perturb the RF signals causing the RF signals to exhibit near field behavior in the complex radio propagation environment. The SOLD receives the locally perturbed signals. The SOLD detects signal characteristics of RF signal components of the received signals and compares these signal characteristics with reference data in a reference data store to determine the current location of the SOLD.

Abstract: A technique is described for determining the correct locations of a plurality of objects by processing signals emitted by a transmitter and reflected by the objects to a plurality of receivers, No angle or elevation information is used. Object-receiver pair time difference of arrival measurements are made to calculate the time difference of arrival between the signals received at each pair of receivers from each object. Hyperbolic localisation is then performed to identify possible locations for each object. Direct-reflected signal time reception measurements are made for each receiver-object pair to calculate the time difference between the reception by the receiver of the direct signal from the transmitter and the signal reflected by the object.

Abstract: A wireless network device including: a first RF transceiver module configured to (i) for a predetermined number of times, transmit a data frame to a second RF transceiver module, and (ii) for each data frame transmitted to the second RF transceiver module, receive an acknowledgement frame from the second RF transceiver module after a respective delay period; a timing module configured to generate a timer value corresponding to an accumulated delay period, wherein the accumulated delay period corresponds to each of the respective delay periods; and a control module configured to (i) determine the predetermined number of times that the first RF transceiver transmitted the data frame to the second RF transceiver based on a resolution of the timing module, and, (ii) determine an actual delay period based on (a) the timer value and (b) the predetermined number of times.

Abstract: Systems and methods for mapping a structure detect wireless signals, including at least one multipath signal that has experienced at least one reflection against a portion of the structure prior to the detection. The wireless signals are analyzed to estimate reflection points for the multipath signal(s), and a map of at least the portion of the structure is generated based on the estimated reflection points.

Abstract: An active imaging system uses communication satellites to identify the location and physical attributes of a target. A transmitter emits a time-synchronized signal directed to a target. The transmitter radiates L-band RF signals. The transmitter can be positioned on an airborne or ground platform. A constellation of communication satellites receives and time stamps the time-synchronized signal reflected from the target to form an active image of the target. The constellation of communication satellites have multiple roles other than active imaging, such as providing voice and data communications. The time-synchronized signal reflected from the target can be received by multiple satellites within the constellation of communication satellites or by multiple antenna disposed on one satellite within the constellation of communication satellites.

Abstract: Systems and methods for actively seeking and generating real-time, conflict-checked, operationally preferred flight trajectory revision recommendations are disclosed. The system analyzes air traffic based on a plurality of uniquely integrated inputs, to produce at least one conflict-checked, operationally preferred flight trajectory revision opportunity for an operating vehicle, and a communications component configured to communicate the at least one conflict-checked flight trajectory revision. In one embodiment, the system interfaces with the airspace user's operations center (e.g. Airline Operations Center), to communicate the operationally preferred flight trajectory revision opportunity, and allow the operator to make the decision whether to implement, and request the same from the Air Navigation Service Provider.

Abstract: A wireless network device comprises a first RF transceiver module and a control module. The first RF transceiver module transmits a first data frame to a second RF transceiver module and receives a first acknowledgement (ACK) frame from the second RF transceiver module after a first delay period. The first RF transceiver module transmits a second data frame to the second RF transceiver module and receives the second ACK frame from the second RF transceiver module after a second delay period. The control module communicates with the first RF transceiver module and determines a total delay period based on the first and the second delay times. The control module determines an actual delay period between the first and the second RF transceiver modules based on the total delay period.

Abstract: Methods and apparatus are described for a navigation system. A process includes providing a plurality of transmitters distributed throughout a desired coverage area; locking the plurality of transmitters to a common timing reference; transmitting a signal from each of the plurality of transmitters. An apparatus includes a plurality of transmitters distributed throughout a desired coverage area; wherein each of the plurality of transmitters comprises a packet generator; and wherein the plurality of transmitters are locked to a common timing reference.

Abstract: The invention relates to the field of electromagnetic detection systems operating in bistatic mode, in particular to UHF/VHF bistatic radars. The method according to the invention consists in the simultaneous use of signals transmitted by one or more transmitting sources on separate frequency channels. The method includes a step of multichannel reception and separating channels. Additionally, the method includes a step of analysis of the signals received channel by channel, wherein the analysis is performed by correlation of the signals received with copies of the time and frequency shifted reference signals. The reference signals are constituted by the signals received from transmitting sources by direct transmission with a step of integration of the signals analysed, channel by channel, and a step of detection.

Abstract: A system and method for providing wireless network services using three-dimensional access zones is provided. One or more sensors may determine signal strength information, distance, or other positional information for wireless devices. An agent may provide information relating to fixed wireless reference points, and may control underlying operating systems for the reference points based on policies defined by a manager. For example, the manager may be coupled to the sensors and to the agent, and may define a three-dimensional coordinate system for a managed environment. By collecting information from the sensors and the agent, the manager may triangulate three-dimensional locations of the wireless devices, and may enforce three-dimensional access zone policies for the wireless network via the agent.

Abstract: A system and technique is described which has the capability to track and identify, in real time, various aircraft and objects including Unmanned Aerial Vehicles (UAVs), Unmanned Combat Aerial Vehicles (UCAVs), and Micro Aerial Vehicles (MAVs). The system uses a combination of techniques including conventional automatic dependent surveillance broadcast (ADS-B), transponder multilateration, broadband emitter multilateration, primary and secondary radar, and passive coherent location. A series of enhancement to conventional passive coherent location are described.

Abstract: A system and method are provided in which an element of a structure may be reliably identified. For example, a system may include a part selection element configured to interact with at least one positional marker having a predefined location. The part selection element is also configured to select at least a portion of a structure, with the structure being positioned at a predetermined location and orientation. The part selection element may also be configured to identify a depth within the structure. The system also includes a computing device configured to identify an element of the structure based upon the position and orientation of the part selection element and the portion of the structure selected by the part selection element. In instances in which a depth is identified, the computing device may also be configured to identify the element of the structure at the depth identified within the structure.

Abstract: According to a method for localizing a transmitter inside a building, a transmitter emits rays which undergo multiple reflections with the walls, ceilings and floors of the building. Each of K receivers receives rays from the transmitter, and the receivers estimates the AOA (Angle of arrival), TOA (Time of Arrival) and power of each ray. At least one of the receivers uses a known blueprint of the building and material characteristics of the walls to localize the transmitter to a higher degree of accuracy by applying a backward ray tracing algorithm.

Abstract: A hybrid wireless location system and method is disclosed for locating mobile stations (MSs). Multiple wireless location techniques (FOMs) are provided for MS location. One or more FOMs can be activated in various combinations (serially or parallelly) for outputting one or more MS location estimates with signal protocols, e.g., CDMA, TDMA, or GSM. Resulting location estimates may be for, e.g.: 911 emergency calls, tracking, navigation, people and animal location, andJor applications for confinement to andlor exclusion from geographical areas. System components may be distributed on a network (e.g., the Internet). FOMs may be based on one or more of: TOA, TDOA, AOA, signal pattern recognitionlfingerprinting, statistical analysis, base station coverage, GPS signals received at the MS, andlor input from mobile stations.

Abstract: A system and method are disclosed to track aircraft or other vehicles using techniques including multilateration and elliptical surveillance. Unlike conventional approaches that use time difference of arrival for multilateration at a fixed set of reception points, this technique allows targets to be tracked from a number of dynamic or moving reception points. This allows for triangulation/multilateration and elliptical surveillance of targets from combinations of fixed, fixed and moving or only moving ground-based receivers, sea-based receivers, airborne receivers and space-based receivers. Additionally this technique allows for ADS-B validation through data derived from only two receivers to assess the validity and integrity of the aircraft self-reported position by comparing the time of arrival of the emitted message at the second receiver to the predicted time of message arrival at the second receiver based on the self-reported position of the aircraft and the time of arrival at the first receiver.

Abstract: A marker navigation device for determining and/or tracking a location of a marker device is provided. The marker device is attachable to an object, said marker device including a plurality of markers having known dimensions and being in a known positional relationship relative to each other. The marker navigation device includes: a detection device operative to detect signals emitted by or reflected from the plurality of markers, wherein the detection device is formed such that in first locations of the detection device relative to the marker device, detection of signals from one marker of the plurality of markers is restricted or impossible due to a location of another marker of the plurality of markers. In second locations of the detection device relative to the marker device, the plurality of markers are detectable by the detection device.

Abstract: A signal processing technique for RF active, passive, or aided localization approaches that utilizes multipath signals as additional measurements with a filter or estimator, e.g., a nonlinear filter. The filter uses indirect and direct path measurements or any other available signals to build parametric models of observable indirect paths. If one or more direct path measurements are subsequently lost (e.g., due to obstruction), the filter maintains an estimate of the position of the person or object of interest using indirect path measurements.

Abstract: Embodiments provide systems and methods for determining the geolocation of an emitter on earth based on weighted least-squares estimation based on two TDOA and two FDOA measurements, none of which need to be acquired at the same time. The four TDOA and FDOA measurements and the errors in each of the measurements are determined. Weights for the errors in the TDOA and FDOA measurements are determined, and the weights are applied in a weighted errors function. The weights account for the errors in the measurements and the errors in the satellite positions and velocities, and are dependent on the localization geometry. The weighted errors function is minimized to determine the location estimate of the unknown emitter.

Abstract: In one embodiment, a method includes computing a probability surface corresponding to the location probability of the wireless node within a physical region based on the received signal strength data associated with a wireless node and an RF model of the physical region; computing, based on the probability surface, an aggregate probability (Pin) of the wireless node being inside a perimeter defined with the physical region; computing, based on the probability surface, an aggregate probability (Pout) of the wireless node being outside the perimeter; computing a probability ratio of the aggregate probabilities Pin to Pout; and determining whether the wireless node is inside or outside the perimeter based on a comparison of Pout and Pin.

Abstract: A method for estimating signal quality of a spread spectrum signal is provided. The method includes squaring a plurality of in-phase correlation results and a plurality of quadrature correlation results, summing each squared in-phase correlation result and the corresponding correlation result to obtain a plurality of sum-of-square values, detecting a peak value among the plurality of sum-of-square results, calculating an average of non-peak values among the plurality of sum-of-square results. The peak value is regarded as a signal power value, while the averaged non-peak values are regarded as an average noise power value. A signal-to-noise ratio is then calculated based on the signal power value and the average noise power value. A method for determining the parameters for the tracking loop is also provided. The method includes estimating the signal-to-noise ratio of the spread spectrum signal, and determining the tracking loop parameters based on the signal-to-noise ratio.