Abstract: According to an example aspect of the present invention, there is provided a system for solar radiation correction in radiosonde temperature measurements, the system comprising a radiosonde having a temperature sensor configured to determine a temperature of the atmosphere at different altitudes, at least one light sensing assembly comprising a light sensor, and a light collector configured to collect light from different solar radiation angles at the different altitudes, and the system further comprising control electronics or a computing device configured to calculate for each altitude a solar radiation correction based on the signal received by the light sensor in order to obtain a corrected temperature reading for each altitude.

Abstract: According to an example aspect of the present invention, there is provided a system for solar radiation correction in radiosonde temperature measurements, the system comprising a radiosonde having a temperature sensor configured to determine a temperature of the atmosphere at different altitudes, at least one light sensing assembly comprising a light sensor, and a light collector configured to collect light from different solar radiation angles at the different altitudes, and the system further comprising control electronics or a computing device configured to calculate for each altitude a solar radiation correction based on the signal received by the light sensor in order to obtain a corrected temperature reading for each altitude.

Abstract: According to an example aspect of the present invention, there is provided a method in connection with a radiosonde, the method comprising measuring a humidity of the atmosphere at several different altitudes in the atmosphere, measuring a pressure at several different altitudes in the atmosphere or calculating the pressure from an altitude of the radiosonde obtained from GPS or other satellite navigation system, measuring or estimating a temperature of a humidity sensor, and measuring a relative humidity by a capacitor with a polymer insulator, wherein the relative humidity value is corrected based on a correction factor, which is a function of pressure, humidity sensor temperature, and relative humidity, such that the humidity value decreases when pressure decreases.

Abstract: According to an example aspect of the present invention, there is provided a method in connection with a radiosonde, the method comprising measuring a humidity of the atmosphere at several different altitudes in the atmosphere, measuring a pressure at several different altitudes in the atmosphere or calculating the pressure from an altitude of the radiosonde obtained from GPS or other satellite navigation system, measuring or estimating a temperature of a humidity sensor, and measuring a relative humidity by a capacitor with a polymer insulator, wherein the relative humidity value is corrected based on a correction factor, which is a function of pressure, humidity sensor temperature, and relative humidity, such that the humidity value decreases when pressure decreases.

Abstract: The present invention relates to a method and apparatus for measuring road surface conditions. In the method of measuring road surface conditions, the conditions prevailing on the surface of a road are measured by a sensor head mounted in the pavement of the road with the top surface of the sensor head aligned substantially flush with the pavement of the road. According to the invention, an optical signal is impinged from below the road to the top surface of the road, the reflection/backscatter of the optical signal is measured inside the pavement layer of the road, and weather/driving conditions prevailing on the road top surface are determined from the reflected and backscattered signal values.