The present invention relates to a method and apparatus for detecting a signal propagation type, the method comprises: when a positioning base station of an ultra-wideband positioning system currently receives a pulse response from a positioning tag, computing an actual value of a specified feature of the received pulse response at least using the received pulse response; selecting, for the specified feature, a predictive model for predicting an adopted value of the specified feature at a future moment on the basis of an adopted value of the specified feature at a historical moment; using the predictive model selected for the specified feature to acquire an adopted value of the specified feature at a future moment, to serve as a predicted value of the specified feature of the received pulse response; and determining the current type of signal propagation between the positioning base station and positioning tag on the basis of the actual value and predicted value of the specified feature of the received pulse response and the predictive model selected for the specified feature. Using the method and apparatus, it is possible to detect the type of signal propagation between the positioning base station and positioning tag of the UWB positioning system.

A search area width setting unit for setting a search area width having a frequency corresponding to a signal component of an object by using detection information of the object is included, and a signal component selecting unit determines a search area having the search area width set by the search area width setting unit and selects a signal component a frequency of which is included in the search area from each of a signal received by a signal receiving unit and signals received by object detection devices. As a result, an increase in the false detection probability of the object can be suppressed even in a case where the reception signals have low signal power-to-noise power ratios.

A system for radiation therapy may obtain a plurality of sets of motion data each of which corresponds to one of a plurality of motion phases of a subject. A set of motion data corresponding to a motion phase may include first physiological motion data and second physiological motion reflecting a physiological motion during the motion phase. The first physiological motion data and the second physiological motion data may be collected via a medical imaging device and a first motion sensor, respectively. The system may also direct a radiotherapy device to deliver a radiation treatment to the subject according to a treatment plan. During the radiation treatment, the system may obtain target physiological motion data reflecting the physiological motion of the subject, the target physiological motion data being collected via a second motion sensor; and adjust the treatment plan to adapt to the physiological motion of the subject.

This beam formation device includes: a Doppler bin detection unit that detects a target Doppler bin which is a Doppler bin in which a target signal is present, from a correlation matrix calculated by a correlation matrix calculation unit and a reception signal vector calculated by a Doppler analysis unit; a target signal removal unit that removes, from the correlation matrix calculated by the correlation matrix calculation unit, the target signal in the target Doppler bin detected by the Doppler bin detection unit and thereby calculates a target-signal-removed correlation matrix from which the target signal has been removed; and a weighting calculation unit that calculates an adaptive weighting of the reception signal vector from the target-signal-removed correlation matrix calculated by the target signal removal unit. A beam formation unit forms an adaptive beam from the reception signal vector calculated by the Doppler analysis unit and the adaptive weighting calculated by the weighting calculation unit.

A method for implementing a relocatable Over-The-Horizon-Radar (OTHR) including transmitting mutually orthogonal signals on each of a plurality of antenna elements of a transmitting system, and receiving and decoding the signals at a plurality of receiving systems to synthesize beams from the orthogonal signals. Each receiving system has a plurality of antenna elements fewer in number than the plurality of antenna elements of said transmitting system. The method includes connecting as a network the transmitting system, the plurality of receiving systems, and a network controller.

System and methods for implementing a vector sensor array surface wave radar is provided. In one or more examples, the system can include a vector sensor array antenna that includes electromagnetic elements collectively configured to receive surface wave reflections generated by radar transmit antenna waves reflecting back from targets of interest. Once received by the vector sensor array, in one or more examples, the system can further include components that can process the incoming signal and use the incoming single to determine the location of one or more targets. In one or more examples, the vector surface array antenna can include three separate loop antennas that are arranged orthogonally to one another, and three dipole antennas that are arranged orthogonally to one another. In one or more examples, the vector surface array antenna can be configured to receive signals in the high frequency (HF) band.

Described are a system and technique to mitigate the impacts of clutter in a radar system. The system and technique require only linear co-polarized measurements can be incorporated into the standard radar signal processing chain without slowing down radar performance.

The invention relates to a system for actuating signal transmitters that are arranged on aviation obstacles, which are obstacles for low-flying airplanes, and signal transmitters for optically warning the airplanes or the pilots thereof, having the following features: a) at least one large-area radar system which is designed to detect airplanes flying at very low altitudes and which is arranged at a location remote from the aviation obstacles, b) at least one computer device which is coupled to the large-area radar system so as to transmit signals and which is designed to evaluate the data provided by the large-area radar system, said data relating to detected airplanes, and to provide such data to other systems via a data connection, and c) at least one data connection between the computer device and multiple aviation obstacles and/or groups of aviation obstacles, wherein d) the computer device is designed to output activation signals for the signal transmitters of aviation obstacles which are being approached by an airplane flying at a low altitude on the basis of the data transmitted by the large-area radar system. The invention further relates to a system for providing data relating to airplanes flying at very low altitudes, to a device comprising a signal transmitter device for aviation obstacles, and to a corresponding actuation device.

A system and method for HF positioning characterizes the undulations of the ionosphere in real-time to determine the refraction altitude of a specific HF frequency at a specific time of day at a specific position. The system accounts for the seasonal (summer, winter) and daily (daylight, night, grey-line transition) variations of the ionosphere determining a highly accurate timing error relative to a timing reference. The system employs a novel approach that is capable of passively and accurately determining a position anywhere in the world without use of a GNSS signal receiving known-time transmissions of narrow band HF timing signals refracted via ionospheric skywave.

Disclosed are various embodiments for exciting a guided surface waveguide probe to create a plurality of resultant fields that are substantially mode-matched to a Zenneck surface wave mode of a surface of a lossy conducting medium and embodiments for receiving energy from a Zenneck surface wave launched on the lossy conducting medium.