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Bernhard Pospichal - One of the best experts on this subject based on the ideXlab platform.

  • Continuous Time Series of Water Vapor Profiles from a Combination of Raman Lidar and Microwave Radiometer
    EPJ Web of Conferences, 2016
    Co-Authors: Andreas Foth, Holger Baars, Paolo Di Girolamo, Bernhard Pospichal
    Abstract:

    In this paper, we present a method to retrieve continuous water vapor profiles from a combination of a Raman lidar and a Microwave Radiometer. The integrated water vapor from the Microwave Radiometer is used to calibrate the Raman lidar operationally resulting in small biases compared to radiosondes. The height limitations for Raman lidars (cloud base and daylight contamination) can be well compensated by the application of a two–step algorithm combining the Raman lidars mass mixing ratio and the Microwave Radiometers brightness temperatures.

  • water vapour profiles from raman lidar automatically calibrated by Microwave Radiometer data during hope
    Atmospheric Chemistry and Physics, 2015
    Co-Authors: Andreas Foth, Holger Baars, Paolo Di Girolamo, Bernhard Pospichal
    Abstract:

    Abstract. In this paper, we present a method to derive water vapour profiles from Raman lidar measurements calibrated by the integrated water vapour (IWV) from a collocated Microwave Radiometer during the intense observation campaign HOPE in the frame of the HD(CP)2 initiative. The simultaneous observation of a Microwave Radiometer and a Raman lidar allowed an operational and continuous measurement of water vapour profiles also during cloudy conditions. The calibration method provides results which are in a good agreement with conventional methods based on radiosondes. The calibration factor derived from the proposed IWV method is very stable with a relative uncertainty of 5 %. This stability allows for the calibration of the lidar even in the presence of clouds using the calibration factor determined during the most recent clear sky interval. Based on the application of this approach, it is possible to retrieve water vapour profiles during all non-precipitating conditions. A statistical analysis shows a good agreement between the lidar measurements and collocated radiosondes. The relative biases amount to less than 6.7 % below 2 km.

Andreas Foth - One of the best experts on this subject based on the ideXlab platform.

  • Continuous Time Series of Water Vapor Profiles from a Combination of Raman Lidar and Microwave Radiometer
    EPJ Web of Conferences, 2016
    Co-Authors: Andreas Foth, Holger Baars, Paolo Di Girolamo, Bernhard Pospichal
    Abstract:

    In this paper, we present a method to retrieve continuous water vapor profiles from a combination of a Raman lidar and a Microwave Radiometer. The integrated water vapor from the Microwave Radiometer is used to calibrate the Raman lidar operationally resulting in small biases compared to radiosondes. The height limitations for Raman lidars (cloud base and daylight contamination) can be well compensated by the application of a two–step algorithm combining the Raman lidars mass mixing ratio and the Microwave Radiometers brightness temperatures.

  • water vapour profiles from raman lidar automatically calibrated by Microwave Radiometer data during hope
    Atmospheric Chemistry and Physics, 2015
    Co-Authors: Andreas Foth, Holger Baars, Paolo Di Girolamo, Bernhard Pospichal
    Abstract:

    Abstract. In this paper, we present a method to derive water vapour profiles from Raman lidar measurements calibrated by the integrated water vapour (IWV) from a collocated Microwave Radiometer during the intense observation campaign HOPE in the frame of the HD(CP)2 initiative. The simultaneous observation of a Microwave Radiometer and a Raman lidar allowed an operational and continuous measurement of water vapour profiles also during cloudy conditions. The calibration method provides results which are in a good agreement with conventional methods based on radiosondes. The calibration factor derived from the proposed IWV method is very stable with a relative uncertainty of 5 %. This stability allows for the calibration of the lidar even in the presence of clouds using the calibration factor determined during the most recent clear sky interval. Based on the application of this approach, it is possible to retrieve water vapour profiles during all non-precipitating conditions. A statistical analysis shows a good agreement between the lidar measurements and collocated radiosondes. The relative biases amount to less than 6.7 % below 2 km.

Paolo Di Girolamo - One of the best experts on this subject based on the ideXlab platform.

  • Continuous Time Series of Water Vapor Profiles from a Combination of Raman Lidar and Microwave Radiometer
    EPJ Web of Conferences, 2016
    Co-Authors: Andreas Foth, Holger Baars, Paolo Di Girolamo, Bernhard Pospichal
    Abstract:

    In this paper, we present a method to retrieve continuous water vapor profiles from a combination of a Raman lidar and a Microwave Radiometer. The integrated water vapor from the Microwave Radiometer is used to calibrate the Raman lidar operationally resulting in small biases compared to radiosondes. The height limitations for Raman lidars (cloud base and daylight contamination) can be well compensated by the application of a two–step algorithm combining the Raman lidars mass mixing ratio and the Microwave Radiometers brightness temperatures.

  • water vapour profiles from raman lidar automatically calibrated by Microwave Radiometer data during hope
    Atmospheric Chemistry and Physics, 2015
    Co-Authors: Andreas Foth, Holger Baars, Paolo Di Girolamo, Bernhard Pospichal
    Abstract:

    Abstract. In this paper, we present a method to derive water vapour profiles from Raman lidar measurements calibrated by the integrated water vapour (IWV) from a collocated Microwave Radiometer during the intense observation campaign HOPE in the frame of the HD(CP)2 initiative. The simultaneous observation of a Microwave Radiometer and a Raman lidar allowed an operational and continuous measurement of water vapour profiles also during cloudy conditions. The calibration method provides results which are in a good agreement with conventional methods based on radiosondes. The calibration factor derived from the proposed IWV method is very stable with a relative uncertainty of 5 %. This stability allows for the calibration of the lidar even in the presence of clouds using the calibration factor determined during the most recent clear sky interval. Based on the application of this approach, it is possible to retrieve water vapour profiles during all non-precipitating conditions. A statistical analysis shows a good agreement between the lidar measurements and collocated radiosondes. The relative biases amount to less than 6.7 % below 2 km.

Holger Baars - One of the best experts on this subject based on the ideXlab platform.

  • Continuous Time Series of Water Vapor Profiles from a Combination of Raman Lidar and Microwave Radiometer
    EPJ Web of Conferences, 2016
    Co-Authors: Andreas Foth, Holger Baars, Paolo Di Girolamo, Bernhard Pospichal
    Abstract:

    In this paper, we present a method to retrieve continuous water vapor profiles from a combination of a Raman lidar and a Microwave Radiometer. The integrated water vapor from the Microwave Radiometer is used to calibrate the Raman lidar operationally resulting in small biases compared to radiosondes. The height limitations for Raman lidars (cloud base and daylight contamination) can be well compensated by the application of a two–step algorithm combining the Raman lidars mass mixing ratio and the Microwave Radiometers brightness temperatures.

  • water vapour profiles from raman lidar automatically calibrated by Microwave Radiometer data during hope
    Atmospheric Chemistry and Physics, 2015
    Co-Authors: Andreas Foth, Holger Baars, Paolo Di Girolamo, Bernhard Pospichal
    Abstract:

    Abstract. In this paper, we present a method to derive water vapour profiles from Raman lidar measurements calibrated by the integrated water vapour (IWV) from a collocated Microwave Radiometer during the intense observation campaign HOPE in the frame of the HD(CP)2 initiative. The simultaneous observation of a Microwave Radiometer and a Raman lidar allowed an operational and continuous measurement of water vapour profiles also during cloudy conditions. The calibration method provides results which are in a good agreement with conventional methods based on radiosondes. The calibration factor derived from the proposed IWV method is very stable with a relative uncertainty of 5 %. This stability allows for the calibration of the lidar even in the presence of clouds using the calibration factor determined during the most recent clear sky interval. Based on the application of this approach, it is possible to retrieve water vapour profiles during all non-precipitating conditions. A statistical analysis shows a good agreement between the lidar measurements and collocated radiosondes. The relative biases amount to less than 6.7 % below 2 km.

Gao Fei - One of the best experts on this subject based on the ideXlab platform.

  • A new algorithm on increasing the sensitivity of Microwave Radiometer based on nonlinear prediction
    Advances in Space Research, 2008
    Co-Authors: Gao Fei
    Abstract:

    Currently, Microwave Radiometer, which has been one of the most important remote sensors in the land, ocean or atmosphere remote sensing, has played a vital role in space exploration such as the lunar exploration in China. As a passive remote sensor, Microwave Radiometer receives the noise resembling signals that are generated by Microwave radiation while mixed with the systemic noise of the receiver. Therefore, it is the significant subject that how to improve the sensitivity of Microwave Radiometer that people devotes to study. And on the system noise reduction lies the key. So far, except through choosing low noise element to the receiver, there is no effective alternative to remove the influence of the systemic noise on output uncertainty of Microwave Radiometer. However, for the purpose of providing or inspiring solution to this problem, this paper inquires into the application of nonlinear predictive method in predication the systemic noise of Microwave Radiometer. As the substance of the method, neural network shows its function on reducing the systemic noise effectively by estimating and predicating it. Because neural network can improve the estimated precision when estimating the systemic noise, after the noise passes through filter, certain random characters are lost while determinacy are presented to some extent. In fact, the more narrow filter band is, the smaller predictive error will be. The results are of assistance in understanding the intrinsic quality of the systemic noise and offer a new way for improving property of Microwave Radiometer.

  • Input Signal Simulation of Spaceborne Microwave Radiometer
    2000
    Co-Authors: Gao Fei
    Abstract:

    The signal given by the antenna of spaceborne Microwave Radiometer is a wide band noise power signal. For the simulation study of Microwave Radiometer under spaceborne condition the input signal of Microwave Radiometer is simulated by artificial random signal. The comparison of the simulation input signal through the simulation model of Microwave Radiometer and actual noise signal through the actual system shows that the linearity of the simulation input signals is very well. The features of radiant objective signal can be shown by the numeral features of the suitably distributed stochastic number. So they may be suitable for simulation study.

  • Simulative Study of Real time Calibrated Microwave Radiometer
    Journal of remote sensing, 1999
    Co-Authors: Gao Fei
    Abstract:

    This paper presents the simulative study of real time calibrated Microwave Radiometer based on the total power Microwave Radiometer. The simulation models of every section are built. In the simulative test, the mathematical means of discrete Fast Fourier Transform is used in signal processing. The contradiction of frequency resolving power and the number samples by the large span of frequency range is analyzed and relieved. The real time calibrated Microwave Radiometer is a new type of Microwave Radiometer. It can efficiently eliminate the influence of system gain fluctuations and effective system noise fluctuations. Thus, it is more suitable to spaceborne Microwave remote sensing. The simulative results in this paper give an important reference to its optimizing design. Also they lay a foundation for the advancement of realizing spaceborne environment debugging.