Abstract: A method for correcting humidity measurement results of a radiosonde, especially for errors resulting from radiative heat exchange. Environmental humidity Um is measured with a humidity sensor in the radiosonde, a current value of at least one environmental condition parameter is determined, and error-corrected humidity U is calculated directly or indirectly utilizing the measured environmental humidity Um and a correction value corresponding to the at least one current environmental condition parameter value.

Abstract: The present invention relates to a method for improving optical measurement of gas concentration. The method comprises steps for directing narrow band light to the gas to be measured and measuring the attenuation of the light in the gas, modulating the center wavelength of the light source around or over a first predetermined absorption maximum (10) (absorption line) of the measured gas and aside of it, measuring the attenuation of the light in the gas as a function of the center wavelength of the light, and determining the gas concentration based on the measurement. According to the invention the center wavelength of the light is varied such that the center wavelength is adapted to coincide with at least one other absorption maximum (11) (peak) with different absorption properties of the gas to be measured, and correspondingly the attenuation of the other absorption maximum or maxima is measured as a function of the center wavelength of the light.

Abstract: This publication discloses a method and apparatus for measuring hydrometeors. According to the method, the mechanical impulses of hydrometers falling on a detection surface are measured. According to the invention, part of the measuring device (1) is used to perform a continuous measurement, in order to define a threshold value for an impulse and only after the threshold value is exceeded is the final part (2) of the measuring apparatus excited for measuring operations, in order to minimize the power consumption of the apparatus.

Abstract: The invention relates to a precipitation detector (1) and method for measurement of precipitation parameters. The detector (1) includes a frame (5), a surface (2) mounted on the frame (5) and adapted to receive hydrometeors, and detection means (3) for converting the impact impulses of hydrometeors into an electric signal. According to the invention, the surface (2) receiving the impact of the hydrometeors is convex, stiff and rigidly connected to the detector frame (4) with the detection means (3) being permanently connected to the surface (2) receiving the impact of the hydrometeors.

Abstract: The present invention relates to a method and apparatus for pointing the beams (63–67) of a wind profiler comprising a stationary antenna matrix (61) with several individual antenna elements (62). According to the method an input signal is fed to the antenna matrix (61), and the phase of the input signal is adjusted for the individual antenna elements (62) in order to point the beam (63–67) of the profiler. In accordance with the invention separate feeder lines for each beam are used for feeding the signals to the antenna elements (62), and the phase differences between the individual antenna elements (62) are controlled with hybrid coupler elements (3, 4).

Abstract: A method for determining the voltage sensitivity of the distance between the mirrors of a Fabry-Perot interferometer in a measuring device, which is intended to measure a predefined gas (CO2), of which at least one absorption maximum or minimum is known. At least two calibration point are defined device specifically using a reference gas (N2) in controlled conditions. A ‘virtual’ signal-control-voltage sensitivity curve, is formed with the aid of the calibration points formed using the reference gas (N2), ratios of the measurement points of the predefined gas (CO2) and of the corresponding values of the reference-gas curve are formed, and at least one voltage value corresponding to the minimum or maximum is defined from the ratios, in which case, on the basis of the wavelengths of the absorption minima or maxima of the gases (CO2, N2) being measured, the voltage sensitivity of the distance between the mirrors can be defined unequivocally.

Abstract: A system and method for processing data related to weather phenomena in a meteorological radar system. The method includes receiving an echo signal generated by transmitting a long pulse and employing a mismatched windowed filter on the echo signal such that the echo signal is compressed in time to achieve fine range resolution without substantially degrading sensitivity and while achieving low range time side lobes for Doppler velocities expected to be measured by the meteorological radar system.

Abstract: This publication discloses a method and apparatus for feeding signal power to an antenna array comprising several antenna elements (1-4). According to the method, the signal power is fed to the antenna elements (1-4) over two transmission lines (a-b) and (c-d), in which case the divisions (e) of one of the transmission lines (a-b) are shorter than the nominal wavelength and those (f) of the other (c-d) are longer than the nominal wavelength by the same amount, the signal s being fed is divided into two parts, one of which is led to one of the said two transmission lines (a) and the other to the opposite end (d) of the other line, in which case the signals travel in the lines in opposite directions, and the signals are summed (5) before the antenna elements (1-5).

Abstract: The invention relates to a method and apparatus for measurement of total water content in a liquid. According to the method, the relative water content (aw) of the liquid is measured in a first measurement step at a first temperature (T1). According to the invention, the temperature of the liquid under measurement is altered from the first temperature (T1) and the relative water content is measured in a second measurement step at the second, altered temperature (T2), whereby, based on these at least two measurement values (aw(1)T1, aw(2)T2), the total water content is determined from the temperature dependence of water dissolution into the liquid under measurement.

Abstract: A lightning detection system provides an estimated location of a lightning stroke. The system includes sensors and an analyzer. Each sensor within range of a lightning event provides messages to the analyzer. Each sensor includes a waveform engine that converts a signal received from the lightning event to a series of frequency domain components having respective magnitude and phase. The waveform engine adjusts magnitudes and phases of the frequency components, for example, to mitigate the effects of terrain conductivity where the received signal traveled across terrain. The adjusted frequency components are then converted by the waveform engine into a second time domain signal that is described in a message to the analyzer. Each message includes sensor identification, peak amplitude, and time of detecting the lightning event. The analyzer provides an estimated location of the lightning stroke and an estimated peak current of the lightning stroke in accordance with messages received from sensors.

Abstract: A capacitive pressure sensor structure, in particular for measurement of absolute pressure, and a method for manufacturing the sensor. The sensor includes at least one fixed electrode, and at least one movable electrode electrically isolated from said fixed electrode and spaced apart from said fixed electrode. A portion of said movable electrode is formed from a porous polycrystalline silicon layer that in a finished component remains as an integral portion of said flexibly movable electrode.

Abstract: The invention relates to lidar, which includes a transmitter (1) and a receiver (2), as well as an optical system, which is arranged to direct at least part of the light sent by the transmitter (1) as a transmitter beam (3) progressing towards an object and to define the receiver beam (4) to the receiver (2), at least part of the light arriving from the zone of which is focussed on the receiver (2). The optical system of the lidar is implemented in such a way that the beams (3, 4) immediately in front of the lidar are located essentially outside of each and one of the beams (3, 4) at least partially surrounds the other beam (3, 4). According to the invention, the optical system includes an integrated optical component (6), which has a first area for forming the transmitter beam (3), and a second area for forming the receiver beam (4).

Abstract: A lightning detection system provides an estimated location of a lightning stroke. The system includes sensors, and an analyzer. Each sensor provides messages having sensor identification, an amplitude responsive to the lightning stroke, and a time of detecting the lightning stroke. The analyzer applies time corrections and amplitude corrections to improve the accuracy of determining the location of the lightning stroke. Time adjustments and amplitude adjustments for the time and amplitude corrections are recalled from a matrix accessed according to a suggested or estimated location. The matrix may be organized by coordinates of longitude and latitude.

Abstract: A method and apparatus for measuring the water content of a liquid, including a method step for electrically measuring the property of the liquid for one parameter. The properties of the liquid are measured at least substantially simultaneously by another electrical method, where the properties of the liquid are measured using both a relative-value and an absolute-value measurement method.

Abstract: A lightning detection and data acquisition system. A plurality of remote programmable sensor is utilized to detect cloud to ground and IC lightning strikes. Analog representations of the lightning strikes are converted to digital signals. The digital signals are classified according to user changeable criteria. The classified digital signals are compressed and optionally decimated. The compressed information is transmitted to a central location where it is decompressed and used to correlate the location, magnitude, and travel path of the detected lightning strikes.

Abstract: A lightning detection and data acquisition system. A plurality of remote programmable sensor is utilized to detect cloud to ground and IC lightning strikes. Analog representations of the lightning strikes are converted to digital signals. The digital signals are classified according to user changeable criteria. The classified digital signals are compressed and optionally decimated. The compressed information is transmitted to a central location where it is decompressed and used to correlate the location, magnitude, and travel path of the detected lightning strikes.

Abstract: A lightning detection system provides an estimated location of a lightning stroke. The system includes sensors and an analyzer. Each sensor within range of a lightning event provides messages to the analyzer. Each sensor includes a waveform engine that converts a signal received from the lightning event to a series of frequency domain components having respective magnitude and phase. The waveform engine adjusts magnitudes and phases of the frequency components, for example, to mitigate the effects of terrain conductivity where the received signal traveled across terrain. The adjusted frequency components are then converted by the waveform engine into a second time domain signal that is described in a message to the analyzer. Each message includes sensor identification, peak amplitude, and time of detecting the lightning event. The analyzer provides an estimated location of the lightning stroke and an estimated peak current of the lightning stroke in accordance with messages received from sensors.

Abstract: A method and system relating to an improvement in measuring accuracy of a gas concentration sensor, the method comprising the steps of measuring a parameter of the sensor, the parameter being a resistance or a capacitance, that is sensitive to the gas or its concentration being measured, and simultaneously changing the temperature of the sensor in a cyclic manner. The parameter of the sensor being measured is measured more than two times or continuously during each heating cycle. The measured parameter value is filtered to obtain a signal component associated with the fundamental frequency of the heating cycle for use at a later step, and the thus filtered signal component is used in the correction and/or calibration of actual output signal of the sensor.

Abstract: The invention relates to a structure suitable for manufacturing by the fabrication techniques of micro-electronics so as to include an optically black surface that functions as an absorber or emitter, respectively, over a predetermined wavelength range, the structure includes a electrically nonconducting support layer (1), a metallic mirror layer (2) made on the support layer (1), and a lossy layer (4) made on the support layer (1) and the metallic mirror layer (2) superimposed thereon. According to the invention, the mirror layer (2) is made on the upper surface of the support layer (1) and the lossy layer (4) is made from a doped semiconductor material. The thickness of the multilayer structure (3, 4, 7) and the doping of the lossy layer (4) are predetermined relative to each other so that the mirror layer (2) will be optically matched over the predetermined wavelength range of absorption or emission, respectively, to the medium surrounding the structure.