Abstract: Embodiments of the invention are directed to improving the sensitivity in polarimetric radar data. In particular, embodiments of the invention improve the sensitivity of such systems with improved post processing techniques. The sensitivity can be improved by using the co-polar elements (off diagonal elements) of the covariance matrix in power and/or reflectivity determinations. This can not only improve the sensitivity but may also enhance identification and improve quantitative estimates of precipitation.

Abstract: A method and a radiosonde wherein the radiosonde is launched from a launching station and transmission of the radiosonde is started in order to send measurement data to a receiver. The transmission of the radiosonde is started only after a delay from the launch.

Abstract: A method and apparatus in connection with a hydrometeor measuring device. According to the method, the amount of precipitation is determined with the aid of the number and size of the hydrometeors. The determining of the size of the hydrometeors is altered as a function of the prevailing atmospheric pressure, in such a way that, the higher the atmospheric pressure, the larger a hydrometeor with the same speed will be estimated to be.

Abstract: A wireless sensor unit and a maintenance method. The sensor unit includes a sensor capable of forming a measurement signal, electronics capable of receiving a measurement signal from the sensor and sending the signal wirelessly to a wireless network, and a power supply for providing supply voltage for the sensor and electronics. The unit is divided into two parts, a first part and a second part such that the first part includes the electronics and is may be mounted permanently to a fixed object like a wall, and second part including the power supply and the sensor. The second part is capable to be repeatedly mounted and detached to the first part.

Abstract: The invention relates to a method and device for calibrating or testing the detector surface (10) of a measuring device (1) detecting hydrometeors. According to the method, impulses are focussed on the detector surface (10) in a controlled manner, the responses caused by the impulses, detected by the detector of the measuring device (1), are measured, the measurement values of the responses are compared with the target values and the required corrections to the settings of the measuring device (1) are analysed, and the measuring device (1) is adjusted on the basis of the analysis. According to the invention, an electromagnetic radiation pulse (70) of short duration is focussed on the detector surface (10), whereby this causes a thermal-expansion reaction in the detector surface (10), detected by the detector.

Abstract: This publication discloses a method for calibrating a CO2 concentration measuring device, in which method gas concentration is measured in a room. In accordance with the invention presence of persons is continuously determined in the room, and the measurement results are corrected based on the presence information.

Abstract: Embodiments of the invention are directed to improving the sensitivity in polarimetric radar data. In particular, embodiments of the invention improve the sensitivity of such systems with improved post processing techniques. The sensitivity can be improved by using the co-polar elements (off diagonal elements) of the covariance matrix in power and/or reflectivity determinations. This can not only improve the sensitivity but may also enhance identification and improve quantitative estimates of precipitation.

Abstract: A method for locating sub-surface natural resources. The method utilizes lightning data to discern relatively likely locations for finding the sub-surface natural resources.

Abstract: Embodiments of the present invention provide estimates of soil moisture by measuring the change in electrical conductivity near the surface of the earth using surface-propagated electromagnetic fields. A method is provided for estimating near-surface soil moisture, including measuring signals from an electromagnetic ground wave propagating between one or more receiving element locations, determining a transfer characteristic proportional to an average electrical conductivity between pairs of locations; and determining estimated soil moisture in one or more regions derived from analyzing the determined electrical conductivity between pairs of locations and a predetermined regional relationship between electrical conductivity and soil moisture.

Abstract: The invention relates to a method for correcting a radiation error in atmospheric temperature measurement, particularly when using a radiosonde (1), a rocket, or a dropsonde, in which method at least one temperature measurement sensor is used in each measuring device. According to the invention, the state of motion of the sonde (1) relative to the ambient air is measured essentially simultaneously with the temperature measurement, and the result of the measurement result is used to correct the error of the temperature measurement.

Abstract: A method for measuring the temperature dependency of a sensor element for a variable, the value of which varies with the temperature, for any liquid. The method includes the steps of changing the temperature of the liquid over time, simultaneously collecting the data produced by the sensor element, and thereafter using the data produced by the sensor element at the different temperatures to determine coefficients for compensation algorithms of the temperature dependencies of the sensor element, thus producing a correlation between the change in temperature and the other measured variables.

Abstract: A method for extension of unambiguous range and velocity of a weather radar. To avoid pulse overlaying, the pulse repetition time of a single pulse can be extended such that any return echo will arrive at the radar before the next pulse is transmitted. When pulse repetition time is increased, the maximum unambiguous range increases while the maximum unambiguous velocity decreases. The pulse overlaying can be avoided if consecutive pulses are sent on different frequencies that are far enough from each other to allow separation of pulses arriving simultaneously at the radar. When different frequencies are used an unknown phase difference is generated by distributed atmospheric targets to the return signals. This normally prevents use of the shorter pulse repetition time for velocity calculation.

Abstract: A method for improving optical measurement of gas concentration includes 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 (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. The center wavelength of the light is varied such that the center wavelength is adapted to coincide with at least one other absorption maximum (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: 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: 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 and apparatus for simultaneous transmission of horizontal (H) and vertical (V) channels in a dual polarized weather radar. The goal of the invention is accomplished by placing the receiver, duplexer and polarizer equipment above the azimuth rotary joint but below elevation rotary joints. The elevation rotary joints and other associated signal paths are calibrated by using a low power signal on the radar's operating frequency that is fed into couplers above the elevation rotary joints.

Abstract: An antenna system and method for measuring azimuth and elevation angles of an active, signal sending radiosonde. The system includes a first passive antenna group having at least two antenna arrays, the direction pattern of which is wide at least in elevation plane for measuring azimuth angle based on the phase differences between the antenna arrays, a second passive antenna group having at least two antenna arrays, the direction pattern of which is wide at least in elevation plane for measuring the elevation angle based on the phase differences between the antenna arrays and the rotational position of the antenna field, and at least one third antenna having high gain for receiving the telemetry signal, the direction pattern of which element is narrow in azimuth plane and wide in elevation plane. The first and second antenna groups form a solid antenna field which is fixedly tilted in a predetermined elevation position.

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: This publication discloses an apparatus and method for measuring a gas content. The apparatus includes a light transmitter (1), by means of which coherent light can be sent to the measurement object (3), a receiver (2), by means of which light that has passed through the measurement object (3) can be detected, and optical means (4, 5, 6), by means of which the light intensity of the light transmitter (1) can be aimed at the receiver (2). According to the invention, the optical means include a lens element (4), the optical axis of which is arranged essentially obliquely relative to the longitudinal axis of the measurement object (3), so that the angles of the normals of the optical boundaries relative to the measuring signal are set obliquely. The lens element (4) is both a refracting and a reflecting element, and separates the measurement object (3) from the means (1, 2, 5).

Abstract: This publication discloses a radiosonde system, a radiosonde system receiver and a signal processing method for use in a radiosonde system. The radiosonde system comprises at least one radiosonde (1) with means for acquisition of position and/or weather data and means for downstream transmission of the data over a radio-frequency path, signal capture means (2, 3) for reception of the weather and/or position data, and receiver means (4) for processing the received signals, the receiver means including RF circuit elements (11) for downconversion of the received signal frequency to a lower frequency known as the first intermediate frequency. According to the invention, the receiver means (4) include sampling means (12) performing sampling at the intermediate frequency, at least two digital mixer means (13) for selective filtration of desired frequency bands from the sampled signal, and processor means (14) for parallel signal processing at the desired frequency bands.