A system and method for measuring the position of one or more object in an area of interest. The system has a primary beacon located at a first fixed position in or near the area of interest which generates a time referenced primary signal, two or more secondary beacons located at different fixed positions in or near the area of interest which generate time referenced secondary signals and one or more portable tag, the portable tag being attachable to the object. The portable tag has a portable tag circuit for calculating the distance of the portable tag to the primary and secondary beacons by a time of flight calculation which uses, the known position of the primary and secondary beacons, time referenced signals and delay information associated with the time referenced signals, such that the portable tag calculates its own position.

A first communication device transmits a first physical layer protocol data units (PPDU) that includes a first null data packet announcement (NDPA) frame as part of a first ranging measurement exchange. The first communication device transmits a first null data packet (NDP) as part of the first ranging measurement exchange, and records a transmit time of the first NDP. The first communication device determines whether a second NDP was received correctly from a second communication device as part of the first ranging measurement exchange. In response to determining that the second NDP was not received correctly, the first communication device commences a second ranging measurement exchange, including transmitting a second PPDU that includes a second NDPA frame as part of the second ranging measurement exchange.

A first communication device transmits a first physical layer protocol data units (PPDU) that includes a first null data packet announcement (NDPA) frame as part of a first ranging measurement exchange. The first communication device transmits a first null data packet (NDP) as part of the first ranging measurement exchange, and records a transmit time of the first NDP. The first communication device determines whether a second NDP was received correctly from a second communication device as part of the first ranging measurement exchange. In response to determining that the second NDP was not received correctly, the first communication device commences a second ranging measurement exchange, including transmitting a second PPDU that includes a second NDPA frame as part of the second ranging measurement exchange.

Methods and apparatus for determining a direction of interest based upon coordinates derived from wireless communication between wireless transceivers. A smart device assembly is operative to communicate via multiple antennas with a reference point transceiver. A set of coordinates is generated indicating a relative position and/or angle of the wireless transceiver in relation to the reference position transceiver. A query may be made based upon the relative position and angle of the wireless transceiver in relation to the reference position transceiver. A response to the query may include a human readable interface indicating one or more of: direction of travel, a virtual image based upon location and location and direction, and annotative and pictorial information.

Systems, methods, and apparatus for detecting UAVs in an RF environment are disclosed. An apparatus is constructed and configured for network communication with at least one camera. The at least one camera captures images of the RF environment and transmits video data to the apparatus. The apparatus receives RF data and generates FFT data based on the RF data, identifies at least one signal based on a first derivative and a second derivative of the FFT data, measures a direction from which the at least one signal is transmitted, analyzes the video data. The apparatus then identifies at least one UAV to which the at least one signal is related based on the analyzed video data, the RF data, and the direction from which the at least one signal is transmitted, and controls the at least one camera based on the analyzed video data.

A system, method, and computer program product are provided for estimating a distance to an object. The system includes a transmitter for transmitting RF signals from a location of an object. The system further includes measurement equipment, including a receiver, for receiving the transmitted RF signals as corresponding received RF signals and measuring a plurality of phase differences at different frequencies between the transmitted RF signals and the corresponding received RF signals. The system also includes a processor. The processor is configured to calculate normalized phases from the plurality of phase differences. The processor is further configured to calculate corrected phases by resolving one or more ambiguities from the normalized phases. The processor is also configured to obtain a characteristic curve using the corrected phases. The processor is additionally configured to provide an estimate of the distance based on the characteristic curve and the corrected phases.

A system, method, and computer program product are provided for estimating a distance to an object. The system includes a transmitter for transmitting RF signals from a location of an object. The system further includes measurement equipment, including a receiver, for receiving the transmitted RF signals as corresponding received RF signals and measuring a plurality of phase differences at different frequencies between the transmitted RF signals and the corresponding received RF signals. The system also includes a processor. The processor is configured to calculate normalized phases from the plurality of phase differences. The processor is further configured to calculate corrected phases by resolving one or more ambiguities from the normalized phases. The processor is also configured to obtain a characteristic curve using the corrected phases. The processor is additionally configured to provide an estimate of the distance based on the characteristic curve and the corrected phases.

A phase rotation amount of each of subcarriers is calculated by calculating a difference between the first phase difference and the second phase difference between consecutive subcarriers included in radio signals, and performing phase addition processing based on the difference. A characteristic coefficient regarding a change rate of the phase rotation amount of each of the subcarriers with respect to a frequency is calculated by performing a linear regression analysis of the relationship between a frequency and the phase rotation amount, and a distance is estimated based on the characteristic coefficient.

Presented are intelligent electronic footwear and apparel with controller-automated features, methods for making/operating such footwear and apparel, and control systems for executing automated features of such footwear and apparel. A method for operating an intelligent electronic shoe (IES) includes receiving, e.g., via a controller through a wireless communications device from a GPS satellite service, location data of a user. The controller also receives, e.g., from a backend server-class computer or other remote computing node, location data for a target object or site, such as a virtual shoe hidden at a virtual spot. The controller retrieves or predicts path plan data including a derived route for traversing from the user's location to the target's location within a geographic area. The controller then transmits command signals to a navigation alert system mounted to the IES's shoe structure to output visual, audio, and/or tactile cues that guide the user along the derived route.

In a method for determining a position of at least two sensors in relation to one another, a moving object is sensed by the at least two sensors, and at least one movement variable for the moving object is determined by one of the sensors, at least said movement variable or variables derived therefrom being used jointly for determining a position of the sensors in relation to one another. The sensor network is designed to carry out a method of said kind.