Provided is a wind turbine including a tower a nacelle, at least one rotatable blade and a measuring apparatus for measuring electromagnetic waves including at least one electromagnetic waves, wherein the electromagnetic waves sensor includes at least one leaky feeder.

Determining which reference-level pressures, from among a plurality of available reference-level pressures, are used when estimating an altitude of a mobile device. Different systems and methods determine isobars based on reference-level pressures of weather stations, and then use the isobars in different ways to identify particular reference-level pressures for use in estimated an altitude of a mobile device. One approach determines the smallest distance between an initial estimated position of a mobile device and a neighboring isobar, and then uses that distance to identify reference-level pressures. Another approach identifies reference-level pressures between an isobar on which an initial estimated position of a mobile device is location and a neighboring isobar. Yet another approach compares the number of identified reference-level pressures and/or locations of the identified reference-level pressures against threshold conditions before determining which reference-level pressures to use.

Determining which reference-level pressures, from among a plurality of available reference-level pressures, are used when estimating an altitude of a mobile device. Different systems and methods determine isobars based on reference-level pressures of weather stations, and then use the isobars in different ways to identify particular reference-level pressures for use in estimated an altitude of a mobile device. One approach determines the smallest distance between an initial estimated position of a mobile device and a neighboring isobar, and then uses that distance to identify reference-level pressures. Another approach identifies reference-level pressures between an isobar on which an initial estimated position of a mobile device is location and a neighboring isobar. Yet another approach compares the number of identified reference-level pressures and/or locations of the identified reference-level pressures against threshold conditions before determining which reference-level pressures to use.

A scientific instrument for measuring neutral atmospheric conditions at satellite altitudes is provided. In an illustrative embodiment, the scientific instrument includes an ion gauge configured to measure ion pressure. The scientific instrument also includes a lid covering the ion gauge. The lid includes a plurality of slits. The scientific instrument also includes an aperture plate that includes an aperture opening. The aperture plate is configured to rotate such that each of the slits are periodically exposed by the aperture opening to allow a neutral beam flux to enter the ion gauge.

A scientific instrument for measuring neutral atmospheric conditions at satellite altitudes is provided. In an illustrative embodiment, the scientific instrument includes an ion gauge configured to measure ion pressure. The scientific instrument also includes a lid covering the ion gauge. The lid includes a plurality of slits. The scientific instrument also includes an aperture plate that includes an aperture opening. The aperture plate is configured to rotate such that each of the slits are periodically exposed by the aperture opening to allow a neutral beam flux to enter the ion gauge.

Determining which reference-level pressures, from among a plurality of available reference-level pressures, are used when estimating an altitude of a mobile device. Different systems and methods determine isobars based on reference-level pressures of weather stations, and then use the isobars in different ways to identify particular reference-level pressures for use in estimated an altitude of a mobile device. One approach determines the smallest distance between an initial estimated position of a mobile device and a neighboring isobar, and then uses that distance to identify reference-level pressures. Another approach identifies reference-level pressures between an isobar on which an initial estimated position of a mobile device is location and a neighboring isobar. Yet another approach compares the number of identified reference-level pressures and/or locations of the identified reference-level pressures against threshold conditions before determining which reference-level pressures to use.

Determining which reference-level pressures, from among a plurality of available reference-level pressures, are used when estimating an altitude of a mobile device. Different systems and methods determine isobars based on reference-level pressures of weather stations, and then use the isobars in different ways to identify particular reference-level pressures for use in estimated an altitude of a mobile device. One approach determines the smallest distance between an initial estimated position of a mobile device and a neighboring isobar, and then uses that distance to identify reference-level pressures. Another approach identifies reference-level pressures between an isobar on which an initial estimated position of a mobile device is location and a neighboring isobar. Yet another approach compares the number of identified reference-level pressures and/or locations of the identified reference-level pressures against threshold conditions before determining which reference-level pressures to use.

[Object] To provide a lightning threat information-providing apparatus, a lightning threat information-providing method, and a program that are capable of providing a user with accurate information regarding a lightning threat. [Solving Means] A lightning threat information-providing apparatus 1 includes: an input unit 10 that inputs observation parameters 11 regarding weather observation data, prediction parameters 12 regarding weather prediction data, and case data 13 regarding a case that occurs in association with lightning occurrence; an intermediate parameter calculation unit that calculates, on the basis of the input observation parameters 11 and prediction parameters 12, an intermediate parameter 27 which is a parameter regarding physical quantity associated with the lightning occurrence and cannot be directly obtained from the observation data or the prediction data; and an arithmetic control unit 20 that estimates a lightning threat on the basis of the observation parameters 11, the prediction parameters 12, the case data 13, and the intermediate parameter 27.

[Object] To provide a lightning threat information-providing apparatus, a lightning threat information-providing method, and a program that are capable of providing a user with accurate information regarding a lightning threat. [Solving Means] A lightning threat information-providing apparatus 1 includes: an input unit 10 that inputs observation parameters 11 regarding weather observation data, prediction parameters 12 regarding weather prediction data, and case data 13 regarding a case that occurs in association with lightning occurrence; an intermediate parameter calculation unit that calculates, on the basis of the input observation parameters 11 and prediction parameters 12, an intermediate parameter 27 which is a parameter regarding physical quantity associated with the lightning occurrence and cannot be directly obtained from the observation data or the prediction data; and an arithmetic control unit 20 that estimates a lightning threat on the basis of the observation parameters 11, the prediction parameters 12, the case data 13, and the intermediate parameter 27.

According to one implementation, an aviation system 100 includes electric field sensors 112 and a ground system 114 including a computer configured to communicate with each of the electric field sensors 112. The computer is configured to: acquire electric field intensities from the electric field sensors 112 respectively, and generate a first electric field distribution on a ground surface 16 based on the electric field intensities; derive a matrix; derive a pseudo inverse matrix of the matrix; derive an electric charge distribution on the horizontal plane by multiplying the pseudo inverse matrix by the first electric field distribution on the ground surface 16; and derive a second electric field distribution on a flight path based on the electric charge distribution. The first electric field distribution on the ground surface 16 is derived by multiplying the matrix by electric charges temporarily set on a horizontal plane at a predetermined altitude.