121 results about "Radio direction finder" patented technology

A technique is disclosed for calculating the phase and amplitude weighting factors for use with a specific compact antenna range that synthesize an in phase, constant amplitude planar wave front that appears to have been transmitted from the far field. The weighting factors are used to weight RF signals after they are received by a full size or scaled radio direction finding array mounted on a platform during testing of the antenna array on the compact antenna range. The weighted received signals accurately replicate the antenna array response in the far field, including electromagnetic glint caused by the platform on which the antennas are mounted, and are stored in complex voltage form as a calibration table for the array.

A method for validating received positional data in vehicle surveillance applications wherein vehicles transmit positional data indicating their own position to surrounding vehicles. A a radio direction finding antenna arrangement of a receiving unit receives a signal carrying positional data indicating an alleged position of a vehicle, transmitted from a radio source. The bearing from the receiving unit to the radio source is estimated utilizing the radio direction finding antenna arrangement and the received signal. The distance between the receiving unit and the radio source is estimated based on the time of flight for a signal travelling there between at known speed. An estimated position of the radio source is calculated based on the estimated bearing and the estimated distance. A deviation value indicating the deviation/coincidence between the alleged position of a vehicle is determined according to the received positional data and the estimated position of the radio source.

The invention discloses a small and medium-sized unmanned aerial vehicle recycling and positioning device, which is applied in the recycling and positioning of the small and medium-sized unmanned aerial vehicles after the parachute landing. The device comprises a vehicle-carrying GPS receiver, a vehicle-carrying wireless mobile communication module, a recycling controller and a parachute landing recycling device which are arranged on an unmanned aerial vehicle and a ground GPS receiver, a ground wireless mobile communication module and a ground processing display module of a ground recycling and poisoning device, as well as a radio beacon on the unmanned aerial vehicle and a radio direction finding device of the ground recycling and positioning device. The small and medium-sized unmanned aerial vehicle recycling and positioning device utilizes the vehicle-carrying wireless mobile communication module and the ground wireless mobile communication module and uses a civil wireless mobile communication network to expand the coverage of the transmission of the recycling and the positioning information; the radio direction finding positioning is adopted to solve the problem that the positioning is unable when the GPS receiver works abnormally after the parachute landing of the unmanned aerial vehicle; the small and medium-sized unmanned aerial vehicle recycling and positioning device can reduce the recycling working amount of the unmanned aerial vehicle, accelerate the recycling speed and have a wide coverage and low cost of the device, which can not only be applied independently, but also be combined with the prior art for application.

Direction findings by radio comprises arraigning an array of antennas, to receive signals from emitters, selecting individual antenna signals using a first multipole switch and determining, antenna signal strengths. Individual antenna signals are also selected by mutipole switch, which routes a selected signal to a third multipole switch. The third switch switches a phase shifter into and out of an antenna signal path. An adder is employed to add an antenna signal in a first signal path extending via the first multipole switch to a different antenna signal in a second signal path extending via the second and third switches. This determines combined signal strengths between pairs of antenna signals, one of which either has or has not been relatively phase shifted depending on the third switch position. Covariance matrix elements are determined from signal strengths enabling emitter bearings to be derived.

The invention discloses an amplitude-phase combined measuring method measuring coning wave direction information; the method can effectively reduce the dependence relation of the phase difference measuring precision with the antenna array dimensions, and can effectively reduce the antenna array dimension; the method comprises the following steps: in a radio direction finding scene, a radio direction finding system employs direction finding antennas of a plurality of array elements to form a multi-channel direction finding antenna array so as to capture coming wave radiation signals; a radio direction finding device uses a radio frequency switch to control a radio frequency channel to select an input antenna signal or a calibration signal, and the radio frequency channel simulates, convertsfrequency, filters and amplifies and outputs the signal to a processing module; the processing module associates obtained space coming wave amplitudes with the phase difference information so as to obtain the coming wave characteristic vectors, selects samples from a sample database according to the signal frequency received in real time, and carries out Euclidean distance operation according tothe real time calculated association vectors and the sample data from the sample database, thus determining the distance extreme value, and obtaining the direction of the coming wave signals.

The invention relates to a sports competition information collection and result calculation device, and especially relates to an orienteering and direction-finding fixed station and fingerprint identity identification electronic timing system. The device can collect information (comprising athlete personal information, competition information and the like) and result (comprising athlete personal competition information value, result validity and the like) statistics in orienteering and radio direction-finding competition activities. The system has the advantages of punch-card station construction in orienteering and radio direction-finding competitions, substantially-reduced maintenance cost, suitableness for the extensive and batch construction of permanent punch-card stations, and realization of the very easy implementation of mass sports activities. Simultaneously the system has the athlete fingerprint collection, storage and comparison functions, can fundamentally avoid and awe cheat phenomena comprising running for an another person and the like existing in the competition activities for a long term, and maintains the justice and the seriousness of the competition activities.

The invention discloses a UAV landing guidance system and method based on multi-mode navigation, belongs to the technical field of UAV flight navigation, and is suitable for vertical take-off and landing UAVs. The system includes the parking stand and the reference point of the parking stand, the cooperative light array, the power supply unit, the radio beacon transmitter, the satellite positioning module I and the communication module I arranged near the parking stand; and the landing guidance module and the satellite arranged on the UAV Positioning Module II. This method uses radio direction finding, visual guidance, satellite positioning and data fusion to guide the UAV to automatically land on the designated parking space. Improve the accuracy and reliability of the drone's autonomous landing, reduce the risk of blind landing, and have good anti-interference. It can be used for UAV landing guidance on fixed platforms and mobile platforms.

The invention relates to the field of radiolocation direction-finding systems, and aims to provide a single-channel radiolocation direction-finding system and a direction-finding method thereof to reduce cost and improve direction-finding accuracy. The single-channel radiolocation direction-finding system is characterized by comprising a direction-finding antenna array, a single-channel receiver with the functions of filtration, amplification, frequency conversion and amplitude limitation, and a direction-finding microprocessor for A/D sampling and digital signal processing, wherein the direction-finding antenna array mainly comprises N identical antenna units which are arranged on the circumference of a concentric circle, wherein N is greater than or equal to 3; and each antenna unit is connected with the single-channel receiver through a radio-frequency electronic switch. The invention utilizes a single-channel radio direction-finding technology combined with a phase interference method and a Doppler direction-finding principle, and only needs one single-channel receiver with the functions of filtration, amplification, frequency conversion and amplitude limitation, thereby reducing the complexity and the cost of equipment, improving reliability, reducing the calculated amount of back-end signal processing, and improving direction-finding accuracy.

The present invention relates to systems and methods to locate and recover objects equipped with tracking devices by determining the location information of the object. The system employs multiple radio direction finding (RDF) devices, which is capable of determining the angle of arrival of a radio signal. The MSC sends a request along with radio information to a location processor, which controls the RDF devices. The system also employs a theft detection device, which is capable of placing a wireless telephone call to a monitoring center. The theft detection device connects to and receives instructions from the monitoring center, which retrieves the instructions from a primary database server. If the primary database server is unavailable, the request for information is sent to a secondary database server.

The invention relates to a sports competition activity information collecting and performance counting device, which can be especially used for information collecting and result counting of various sports events by using specified path visiting and completing time as the competition performance assessing standard. The invention provides a two-dimension code and non-contact IC (Integrated Circuit) card information collecting and electronic timing system, which can be used for field and station construction, information collecting and result counting of a temporary or permanent maintenance-free electronic timing system of outdoor sports events such as orientation movement, radio direction finding movement, mass mountaineering, walking, campus orientation movement and treasure seeking activity, bicycle riding, cross-country ski race and outdoor challenge matches with very low cost. And meanwhile, by use of the set of the system disclosed by the invention, a professional judgment team and a special-purpose competition device are not needed on site during the competition and entertainment and challenges of the events are increased, so that daily mass body-building, competition and entertainment events can be conveniently popularized.

The invention discloses a single-channel radio direction finding system. The single-channel radio direction finding system comprises an antenna array, a single-pole double-throw radio frequency switch module, a radio frequency receiving channel, a spectral analysis module, a control module and an output display module, wherein the antenna array is connected with the single-pole double-throw radio frequency switch module, the single-pole double-throw radio frequency switch module is connected with the radio frequency receiving channel, the radio frequency receiving channel is connected with the spectral analysis module, the spectral analysis module is connected with the control module, and the control module is connected with the single-pole double-throw radio frequency switch module and the output display module. The single-channel radio direction finding system is used for solving the problem of radio direction finding in the communication application, the military application and the like, the antenna array which is controlled by a high-speed radio frequency switch and carries out periodic switching is adopted, and measurement of the radio incident direction is achieved through analysis of frequency spectrum components of a received radio signal. The single-channel radio direction finding system is applicable to rapid radio direction finding needing low hardware complexity and low cost.

Systems and methods to determine the location information of an emergency call made from a radiotelephone. The system employs multiple radio direction finding (RDF) devices, which is capable of determining the angle of arrival of a radio signal. The MSC sends a request along with radio information to a location processor, which controls RDF devices. The location processor sets up each RDF device to track the radio signal. If at least two RDF devices are successful in tracking the radio signals and returning information about the radio signal, then the location processor can determine the location of the radiotelephone by using a triangulation method.

The invention discloses a dual-satellite time difference measurement direction-finding method and apparatus for aerial target positioning. The direction-finding method comprises the following steps that: a primary satellite carries out radio direction finding on a target so as to obtain direction-finding vector information; time for arriving at the primary satellite and an auxiliary satellite by radio singles are respectively measured and the arrival time is compared so as to obtain time difference measurement information; and according to the direction-finding vector information and the time different measurement information, position information of the target is resolved. According to the dual-satellite time difference measurement direction-finding system, both the aerial target positioning and positioning of a ground target and a space target can be realized; and thus the provided method and the apparatus have high application values in the radio positioning field.

The invented antenna assembly is the antenna aerial array of multi-layer folding units. Each folding unit antenna comprises folding cross arm, folding vibrator, locating piece and sleeve as well as center rod, base, connecting rod and shaft lever parts etc. Multi-layer folding vibrator and sleeve make the vibrator possible to be folded and unfolded quickly. Multi-layer folding cross arms and locating pieces make the cross arms possible to be folded and unfolded quickly. The invention possesses the features of accurate positioning, easy operation, lightweight and small size. It is suitable to vehicle carried antenna assembly or in mobile station for communication countermeasures, radio direction finding and radio monitoring.

The invention discloses an unmanned aerial vehicle operator positioning system and method based on an aerial radio monitoring platform and belongs to the technical field of radio direction finding andpositioning. The unmanned aerial vehicle operator positioning system comprises an airborne direction finding system and a ground control system; the airborne direction finding system is used for measuring the direction of arrival from the maximum energy of a target signal to determine a position; the ground control system is used for remotely controlling the airborne direction finding system andthe aerial monitoring platform to obtain a positioning result in real time. The airborne direction finding system is used for acquiring and compressing the target signal, performing frequency hoppingsignal extraction and matching an azimuth angle, a GPS position and time information, and a frequency hopping signal in real time; the ground control system is used for controlling the aerial radio monitoring platform to change postures in air, so that the airborne direction finding system determines the direction of arrival from the maximum energy of the target signal. The unmanned aerial vehicleoperator positioning system and method based on the aerial radio monitoring platform, disclosed by the invention, are suitable for an area where multi-point ground monitoring equipment is unconditionally erected in a complex urban environment, save labor and capitals, and realize wide-frequency band, omni-directional and high-precision spatial positioning of the remote frequency hopping signal.

A calibration method and a system for providing calibration data for use with a direction finder are provided. The method comprises providing a relative motion of a calibration receiver in a circle manner with respect to calibration transmitter at a predetermined distance from each other. The method also includes preparing and transmitting a communication frequency signal employed for transmitting a certain frequency from a list of predetermined frequencies. The preparing comprises: (a) setting a value of the dwell time ranges of the communication frequency signal to a predetermined value; (b) synchronizing in time the dwell time ranges between the calibration transmitter and the calibration receiver by using clock signals of a common synchronization source; (c) providing a hop duration time interval within the dwell time range for transmitting the frequency; and (d) generating the communication frequency signal corresponding to the frequency during the hop duration interval. At the calibration receiver end, the method includes scanning the list of predetermined frequencies; intercepting a frequency signal transmitted during the hop duration time interval within the dwell time ranges; and rejecting all other frequency signals received within the dwell time ranges having duration different than the hop duration time interval by the receiver.

The invention provides a method for constructing a figure and an RDF (Radio Direction Finder) model for designing an intelligent transformer substation. The method provided by the invention comprises the following steps of: utilizing the RDF to describe an IEC61850 model through utilizing the same form of an IEC61970CIM (Computer Integrated Manufacturing) to obtain an RDFSchema of the IEC61850 model for assuring the structure of the IEC61850 model object. The structure of the IEC61850 model object comprises model types, mode type attributes and incidence relations between the model types. By utilizing the method to design model types of the intelligent device and virtual terminals and a design tool of a graphics primitive development secondary system, the engineering design of the secondary system of the intelligent transformer substation can go deep into a logical layer so that an interoperable relation of logical functions can be described by means of imaging and the design assignment of the intelligent transformer substation can be smoothly processed. The model of a primary system is described by utilizing the IEC61970-CIM model so that the compatibility and the interoperability between the model and the primary system model data utilized by a dispatching mechanism can be realized.

The invention discloses a double-satellite tracking method and device for a moving target. A main satellite carries out radio direction finding on the moving target to obtain direction of arrival (DOA) of the moving target; the main satellite estimates signal arrival time difference (TDOA) and signal arrival frequency difference (FDOA) according to a target signal x(t), received by the main satellite itself, of the moving target and a target signal y (t), transmitted by an auxiliary satellite through inter-satellite communication, of the moving target; and the main satellite estimates position and speed of the moving target at each moment by utilizing a particle filtering algorithm according to the direction of arrival, the signal arrival time difference and the signal arrival frequency difference, so that not only positioning and tracking of the high-speed moving target in the air can be realized to obtain the position and speed of the moving target, but also recursive estimation of position and speed state quantity of the moving target, which cannot be realized in the prior art, can be realized, and result precision is improved greatly.

The invention provides a radio direction finding system and a radio direction finding method. According to the radio direction finding system and the radio direction finding method, based on the framework of a double-base wire antenna, the distances between antennae which are adjacent in a certain direction are set to be larger than or equal to 0.5 time of the wave length, and the distance difference is set to be smaller than 0.5 times of the wave length; corresponding intermediate-frequency signals are generated after a double-channel homologous receiver module conducts frequency selection, filtering, amplification and down-conversion on received radio-frequency signals, and then the intermediate-frequency signals are sent to a direction finding plate to be processed; finally, differential processing is conducted on a double-base wire for direction finding. According to the radio direction finding system and the radio direction finding method, the difference method is adopted to eliminate phase ambiguity, the method is easy to realize, the realizing speed is high, and the number of occupied resources is small; due to the adoption of an orthogonal phase discriminator, errors caused by the change of the amplitudes of the received signal can be eliminated, antenna phase discrimination results are more accurate, and a measurement angle can be obtained more accurately.

The invention provides a radio direction-finding simulation system and method. The system comprises a beacon unit and a direction-finding and tracking unit, wherein the direction-finding and trackingunit comprises a direction-finding unit and a tracking trolley; the direction-finding unit is connected with the tracking trolley through a driving interface; the tracking trolley is used for carryingthe direction-finding unit and travelling to search the beacon unit after receiving the driving signal of the direction-finding unit, and the direction-finding unit is used for radio direction finding and driving the tracking trolley to search the beacon unit, and the beacon unit is used for sending and releasing radio signals and collision alarm. The direction-finding system is characterized inthat the direction-finding unit automatically drives the tracking trolley to search the beacon unit after the direction-finding calculation, the prior manual debugging direction-finding tracking is replaced, the technical design capability of students is tested, the system is suitable for radio direction-finding simulation teaching, experiment, training and electronic sports in colleges and universities, the application and implementation of the system can exercise and cultivate the professional technical ability, innovation ability, operation ability and the like of the students.

The invention relates to a phase interferometer based on a broadband dual-polarized antenna array and a direction finding method thereof. The phase interferometer based on a broadband dual-polarized antenna array is characterized in that the phase interferometer comprises three double-polarized ultra-broadband loudspeaker-equipped antenna units, a metal mounting base and a broadband microwave absorbing material, wherein the double-polarized ultra-broadband loudspeaker-equipped antenna has a metal structure; two polarized ports are orthogonally placed; coaxial bottom feeding is utilized; a slit has a continuous gradual change structure; the bottom of each antenna unit has a waveguide chamber structure, thereby realizing an impedance matching function; a gradual change structure is adopted on four metal arms at periphery of the chamber, thereby further realizing impedance matching and reducing voltage standing-wave ratio; and chamfering is performed on four ridges of the antenna, thereby reducing the voltage standing-wave ratio of two ports. The phase interferometer and the direction finding method thereof are suitable for spaceborne, airborne, missile-borne and other related radio direction finding systems and have a more comprehensive parameter measuring function and higher platform adaptability.

The invention relates to an indicating apparatus for scores of sports competitions. Particularly, the indicating apparatus provided by the invention can automatically indicate competition scores in cross-country orienteering and radio direction finding competitions. A technical scheme employed in the invention for solving a technical problem is as follows: an electronic clocking device (a master-substation) outputs a control signal, and a display device is allowed to carry out clear displaying by using a drive control device and an auxiliary device, thereby enabling automatic displaying and recording of scores of athletes in cross-country orienteering and radio direction finding competitions to be realized and validity of arriving of an athlete to be seen by the athlete, other athletes, referees and spectators. The invention provides a series of solutions.