A method for positioning a target in a building based on the assistance of two aircraft includes the following steps: allowing two aircraft with respective direction-finding devices to fly around a building, and sending a signal by a positioning tag carried by an indoor target; measuring projections of directions of the signal source on a horizontal plane respectively by the two aircraft, and indicating a position of the indoor target on the horizontal plane by an intersection of the two projections; and according to a difference between barometric pressures of the indoor target and the aircraft, obtaining an altitude of the target to further obtain position coordinates of the target. The method avoids deploying an indoor positioning base station, and improves the positioning accuracy, stability and anti-interference performance.

A method of localizing a near vertical incidence skywave emitter. At a first site a first elevation angle of an incoming signal issued by the near vertical incidence skywave emitter is measured. At a second site a second elevation angle of an incoming signal issued by the near vertical incidence skywave emitter is measured, wherein the second site is different to the first site. The first elevation angle measured and the second elevation angle measured are converted into a first length and a second length respectively, which represent the distance between the respective site and the estimated location of the near vertical incidence skywave emitter. The respective length is processed, thereby generating an estimated area of the near vertical incidence skywave emitter for each of the different sites such that at least two different estimated areas are generated. The estimated areas for each site are superimposed, thereby obtaining an area of interest encompassing the estimated location of the near vertical incidence skywave emitter. Further, a direction finding system is described.

A method of localizing a near vertical incidence skywave emitter. At a first site a first elevation angle of an incoming signal issued by the near vertical incidence skywave emitter is measured. At a second site a second elevation angle of an incoming signal issued by the near vertical incidence skywave emitter is measured, wherein the second site is different to the first site. The first elevation angle measured and the second elevation angle measured are converted into a first length and a second length respectively, which represent the distance between the respective site and the estimated location of the near vertical incidence skywave emitter. The respective length is processed, thereby generating an estimated area of the near vertical incidence skywave emitter for each of the different sites such that at least two different estimated areas are generated. The estimated areas for each site are superimposed, thereby obtaining an area of interest encompassing the estimated location of the near vertical incidence skywave emitter. Further, a direction finding system is described.

The present invention provides a low-cost and low-volume mode A/C/S transponder positioning system to detect the position of a target aircraft, or intruder, outside the range of a secondary surveillance radar system. The system uses a signal of the intruder to pinpoint the location of the intruder. The system can be used on both the ground and on an aircraft in a full 360 degree range around the system.

The present invention provides a low-cost and low-volume mode A/C/S transponder positioning system to detect the position of a target aircraft, or intruder, outside the range of a secondary surveillance radar system. The system uses a signal of the intruder to pinpoint the location of the intruder. The system can be used on both the ground and on an aircraft in a full 360 degree range around the system.

This application provides a screen projection method and an electronic device. The method includes: detecting a position of one or more other electronic devices relative to a first electronic device by using a Bluetooth angle of arrival (AOA) technology (S1601); determining a target device from the one or more other electronic devices based on the position of the one or more other electronic devices relative to the first electronic device (S1602); detecting a screen projection operation (S1603), and sending first information to the target device in response to the screen projection operation, so that the target device displays or plays the first information (S1604). In the method, the electronic device may automatically determine a target electronic device from a plurality of electronic devices, and then project a screen on the target electronic device, to facilitate operations and improve user experience.

This application provides a screen projection method and an electronic device. The method includes: detecting a position of one or more other electronic devices relative to a first electronic device by using a Bluetooth angle of arrival (AOA) technology (S1601); determining a target device from the one or more other electronic devices based on the position of the one or more other electronic devices relative to the first electronic device (S1602); detecting a screen projection operation (S1603), and sending first information to the target device in response to the screen projection operation, so that the target device displays or plays the first information (S1604). In the method, the electronic device may automatically determine a target electronic device from a plurality of electronic devices, and then project a screen on the target electronic device, to facilitate operations and improve user experience.

An exemplary compliance monitoring system includes a dispenser for dispensing soap or sanitizer, a one people counter for detecting the presence of one or more persons or assets, at least one badge and at least one locatee device. The locatee device includes an antenna and transmitting circuitry for transmitting signals. At least one of the dispenser, the people counter, and the one or more badges include a locatee device. A locator device is also provided. The locatee device circuitry includes wake-up circuitry for instructing the locatee device circuitry to transmit one or more signals, at least two antennae, triangulation based measurement circuitry to determine the angle of arrival of the one or more signals, and wake-up circuitry for waking up the triangulation based measurement circuitry. The wake-up circuitry causes the triangulation based measurement to listen for the one or more signals from the at least one locatee device.

An exemplary compliance monitoring system includes a dispenser for dispensing soap or sanitizer, a one people counter for detecting the presence of one or more persons or assets, at least one badge and at least one locatee device. The locatee device includes an antenna and transmitting circuitry for transmitting signals. At least one of the dispenser, the people counter, and the one or more badges include a locatee device. A locator device is also provided. The locatee device circuitry includes wake-up circuitry for instructing the locatee device circuitry to transmit one or more signals, at least two antennae, triangulation based measurement circuitry to determine the angle of arrival of the one or more signals, and wake-up circuitry for waking up the triangulation based measurement circuitry. The wake-up circuitry causes the triangulation based measurement to listen for the one or more signals from the at least one locatee device.

Geolocated information is communicated to a user based upon a position of smart device in a building as determined by optical recognition of a first visual identifier, a second visual identifier and a third visual identifier. A distance determined from each of the visual identifiers, as well as a direction of interest indicated by a user. A user interface is generated for display on a Smart Device based upon the position of the Smart Device and direction of interest.