The present disclosure obtains a correction value that corrects measurement angle error signals more accurately than conventional methods even in a case where a radio wave signal-to-noise ratio is low, and thus tracks a communication counterpart more accurately than the conventional methods. The present disclosure includes a program controller 28 that generates a command value of an orientation direction of an antenna 1 and outputs the generated command value to an antenna drive controller 27, the command value being changed in accordance with a predetermined change scenario 54; a correction value calculator 32 that calculates a phase correction value γ, based on at least three pieces of error measurement data 55 including (i) an arrival direction error obtained from a sum signal and a difference signal of reception signals, the arrival direction error representing a difference between the orientation direction and an arrival direction being a direction from which the radio waves come and arrive and (ii) an orientation direction actual measurement value being an actual measurement value of the orientation direction when the arrival direction error is obtained, the phase correction value γ being an angle by which the arrival direction error is rotated; and a tracking controller 33 that outputs, to the antenna drive controller 27, as the command value, a value obtained by adding the arrival direction error corrected based on the phase correction value γ to the orientation direction actual measurement value.

There is provided mechanisms for estimating angle of arrival of a radio signal in a radio communications network. A method is performed by a receiving radio transceiver device. The method comprises obtaining measurements of the radio signal as received in two receive beams covering a given angular sector. The two receive beams are created by analog beamforming in an antenna array. The receive beams have different complex beam patterns and at any angle within the given angular sector at most one of the complex beam patterns has gain below a threshold. The method comprises estimating the angle of arrival of the radio signal by comparing a complex amplitude of the measurements in the two receive beams to a discriminator function.

A method and apparatus for reducing magnetic tracking error in the position and orientation determined in an electromagnetic tracking system is disclosed. In some embodiments, a corrected position and orientation is blended with an uncorrected position and orientation based upon the calculated probability of each. To determine a corrected position and orientation, data from an IMU in the receiver is used to obtain a constraint on the orientation. In other embodiments, the amount of detected error due to electromagnetic distortion is measured. Any error is first assumed to be from “floor distortion,” and a correction is applied. If the error is still deemed too great, a constraint is again obtained from IMU data. Using this constraint, another correction for the distortion is made. The solution from this correction may be blended with a standard solution and the solution from the floor distortion to arrive at a final solution.

A POL-axis driving unit, an EL-axis driving unit, a Cross-EL-axis driving unit and an AZ-axis driving unit of an antenna apparatus drive respective axis drive motors controlled by a control unit of a control apparatus, such that the antenna performs an origin detection operation for each axis. The camera control unit controls a camera so as to capture an image of the antenna at each timing before and after the origin detection for each axis. An image acquisition unit of an antenna inspection acquires image data that indicates the image of the antenna captured by the camera and makes storage unit store the image data. A comparing diagnosis unit compares image data before the origin detection for each axis with image data after the origin detection, and diagnoses whether the antenna is in a normal state.

Systems, methods, and apparatus cause a first wireless device to transmit to a plurality of locator devices, an extended signal including a first segment and second segment. The first segment includes an indication for each of the plurality of locator devices to listen for a change in the extended signal from the first segment to the second segment. The second segment includes an indication for each of the plurality of locator devices to rotate through a plurality of antennas to receive the second segment via the plurality of antennas. Responsive to the transmitting of the extended signal, receiving direction data from each of the plurality of locator devices.

Apparatuses and methods are disclosed that allow for the detection, identification and direction finding of search and rescue beacons in a variety of environments. The techniques may be used to identify a line of bearing (LOB) to 121.5 MHz rescue beacons found in aircraft (ELTs), marine beacons (EPIRBs), and personal locator beacons (PLBs). Multiple lines of bearing may be used to geo-locate a target emitter if so desired. The methods may utilize, for example, a handheld device that is designed for search and rescue activity. Additionally, this device may be able to decode a 406 MHz frequency beacon that communicates with the satellite system that is controlled by COSPAS SARSAT. This constellation of rescue satellites coordinates the location of 406 MHz rescue beacons.

A method for direction finding of at least one stationary and/or moving transmitter comprises the following steps: measuring the signals emitted by each of the at least one transmitter at at least two different measurement points; determining the location of the measurements points at the time of the measurement; determining the bearings from the measurement points to each of the at least one transmitter; transferring the bearings to a pre-trained artificial neural network; and estimating the locations of the at least one transmitter by the artificial neural network. Further, a system for direction finding of at least one stationary and/or moving transmitter is shown.

A tracking receiver includes: a complex sum signal generator to generate a complex sum signal; a complex difference signal generator to generate a complex difference signal; a first correction coefficient storage to store a first correction coefficient represented by a complex number; complex difference signal correcting circuitry to calculate a corrected complex difference signal by correcting the complex difference signal based on the complex sum signal and the first correction coefficient; and an orientation direction error calculator to calculate an orientation direction error based on the corrected complex difference signal and the complex sum signal, the orientation direction error being a difference between an arrival direction and an orientation direction, the arrival direction being a direction from which the radio wave comes and arrives, the orientation direction being a direction in which the antenna is orientated.

A tracking receiver includes: a complex sum signal generator to generate a complex sum signal; a complex difference signal generator to generate a complex difference signal; a first correction coefficient storage to store a first correction coefficient represented by a complex number; complex difference signal correcting circuitry to calculate a corrected complex difference signal by correcting the complex difference signal based on the complex sum signal and the first correction coefficient; and an orientation direction error calculator to calculate an orientation direction error based on the corrected complex difference signal and the complex sum signal, the orientation direction error being a difference between an arrival direction and an orientation direction, the arrival direction being a direction from which the radio wave comes and arrives, the orientation direction being a direction in which the antenna is orientated.

A method determines a presence of a motor-driven tool inside a tool position region and/or a tool position of the tool. A transmitter is mechanically connected to the tool, wherein the transmitter wirelessly transmits a signal. The transmitted signal is attenuated by the tool and has an item of transmitter information for taking the attenuation into account. The method has the steps of: capturing a respective reception signal strength value of the transmitted signal at receivers, wherein the receivers are arranged at different receiver positions; and determining the presence of the tool inside the tool position region and/or the tool position of the tool on the basis of the captured reception signal strength values and the received transmitter information for taking the attenuation into account.