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1. chinaXiv:201703.00308 [pdf]

Target brightness temperature simulation and analysis for the geostationary interferometric microwave sounder (GIMS)

Zhang, Ying; Liu, Hao; Wu, Ji; He, Jieying; Zhang, Cheng
Subjects: Geosciences >> Space Physics

Target brightness temperature maps can be used in geostationary interferometric microwave sounder (GIMS) system simulation. System simulation with accurate target brightness temperature maps can evaluate system performance in near real case and thus help adjust design parameters for the sensor before it is finally put into use. In this paper, method of simulating target brightness temperature using Weather Research and Forecasting Model and Radiative Transfer for TOVS (RTTOV) has been discussed. Target brightness temperature simulation results at oxygen absorption band and water-vapor absorption band have been presented. Some preliminary analyses of simulated brightness temperature for GIMS' observation have also been given.

submitted time 2017-03-10 Hits13016Downloads734 Comment 0

2. chinaXiv:201703.00298 [pdf]

A deblurring method for dynamic target observation of the geostationary interferometric microwave sounder (GIMS)

Zhang, Ying; Liu, Hao; Wu, Ji; Zhang, Cheng; He, Jieying
Subjects: Geosciences >> Space Physics

Brightness temperature change of observation target in one imaging period will introduce image blur to the retrieved image of geostationary interferometric microwave sounder (GIMS), which uses rotating circular array to realize time-sharing sampling other than snap-shot to reduce system complexity but meanwhile resulting in a relatively long imaging period. In this paper, an interpolation method utilizing time sequence of visibilities collected by time-sharing sampling is presented. The method is verified through a simulation system that simulates GIMS's observation process in viewing a series of near real case brightness temperature maps modeled by FNL/WRF/RTTOV method. Results show that the interpolation method can de-blur the image and reduce imaging error to the degree of snap-shot imaging. �2016 IEEE.

submitted time 2017-03-10 Hits1214Downloads385 Comment 0

3. chinaXiv:201703.00291 [pdf]

Analysis and simulation of GIMS observation on dynamic targets

Zhang, Ying; Liu, Hao; Wu, Ji; Zhang, Cheng; He, Jieying
Subjects: Geosciences >> Space Physics

Imaging period is an important consideration to geostationary interferometric microwave sounder (GIMS) when mapping fast changing target such as typhoon. GIMS simulation system with near real case observation target can evaluate system performance in different system configurations and thus help determine the optimal imaging period. In this paper, GIMS simulation system using MATLAB and near real case observation modeled by FNL/WRF/RTTOV method has been used to analyze the effect of imaging period on image quality. System simulation results for each frequency channel will be presented and analyses of imaging period's effect on image quality will also be given. �2016 IEEE.

submitted time 2017-03-10 Hits1162Downloads353 Comment 0

4. chinaXiv:201703.00288 [pdf]

Inter-element phase self-calibration for GIMS (geostationary interferometric microwave sounder)

Han, Donghao; Liu, Hao; Wu, Ji; Zhang, Cheng
Subjects: Geosciences >> Space Physics

The inter-element phase calibration plays an important role in the overall calibration scheme for synthetic aperture radiometer. The traditional relative phase calibration approach is to use correlated noise injection network, which will be difficult to be implemented in millimeter wave band due to the complexity of the waveguide divider network. A novel self-calibration method for interferometric radiometers with rotating thinned array, especially for the geostationary interferometric microwave sounder(GIMS), has been proposed in this paper. By using this approach, neither dedicated hardware nor dedicated calibration working model is needed to achieved the relative phase calibration. The self-calibration approach is inherently merged with the nominal observation working model of GIMS, thanks to the continuous array rotating of GIMS instrument. A running average scheme has been introduced into the self-calibration approach to enhance the SNR of the calibration data, which is normally very low with the natural earth scene. The method is demonstrated by both simulation and field imaging experiment. �2016 IEEE.

submitted time 2017-03-10 Hits647Downloads378 Comment 0

5. chinaXiv:201703.00287 [pdf]

Passive submillimeter-wave imaging demonstrated by a two-element interferometer

Han, Dong-Hao; Liu, Hao; Zhang, De-Hai; Meng, Jin; Zhao, Xin; Zhang, Ying; Wu, Ji
Subjects: Geosciences >> Space Physics

In this paper, an SMMW interferometric radiometer concept is demonstrated by a two-element interferometer with dedicated high accuracy SMMW devices. Point-source calibration method is introduced in order to reduce instrument errors. Interference fringes and point target images are presented by this SMMW interferometer. The linear phase error of the interference fringes is less than 2�and the angular resolution is better than 0.57� The measured performance characteristics of the two-element interferometer are consistent with the theoretical analysis. This interferometer demonstrates a new method for passive SMMW remote sensing. �2016, Science Press. All right reserved.

submitted time 2017-03-10 Hits748Downloads420 Comment 0

6. chinaXiv:201605.00283 [pdf]

TARGET BRIGHTNESS TEMPERATURE SIMULATION AND ANALYSIS FOR THE GEOSTATIONARY INTERFEROMETRIC MICROWAVE SOUNDER (GIMS)

Zhang, Ying; Liu, Hao; Wu, Ji; He, Jieying; Zhang, Cheng
Subjects: Geosciences >> Space Physics

Target brightness temperature maps can be used in geostationary interferometric microwave sounder (GIMS) system simulation. System simulation with accurate target brightness temperature maps can evaluate system performance in near real case and thus help adjust design parameters for the sensor before it is finally put into use. In this paper, method of simulating target brightness temperature using Weather Research and Forecasting Model and Radiative Transfer for TOVS (RTTOV) has been discussed. Target brightness temperature simulation results at oxygen absorption band and water-vapor absorption band have been presented. Some preliminary analyses of simulated brightness temperature for GIMS' observation have also been given.

submitted time 2016-05-03 Hits559Downloads361 Comment 0

7. chinaXiv:201605.00282 [pdf]

IMAGING SIMULATION OF THE MICROWAVE RADIOMETER ABOARD THE MICAP FOR SEA SURFACE SALINITY MEASUREMENT

Zhang, Cheng; Liu, Hao; Wu, Lin; Wu, Ji
Subjects: Geosciences >> Space Physics

Sea surface salinity as an ocean variable plays an important role in various components of the water and energy cycle. Recently a Chinese space mission using a new concept of Microwave Imager Combined Active and Passive (MICAP) at L-band is proposed for the ocean salinity measurement. MICAP uses interferometric techniques for both the radiometer and the scatterometer, which adopt two kinds of linear array feeds sharing one 3x4.5 m parabolic cylinder reflector. This paper is focused on the microwave interferometric radiometer (MIR) aboard the MICAP, and discusses the imaging simulation, imaging algorithm, and instrument performance.

submitted time 2016-05-03 Hits591Downloads351 Comment 0

8. chinaXiv:201605.00280 [pdf]

MICAP (MICROWAVE IMAGER COMBINED ACTIVE AND PASSIVE): A NEW INSTRUMENT FOR CHINESE OCEAN SALINITY SATELLITE

Liu, Hao; Zhu, Di; Niu, Lijie; Wu, Lin; Wang, Caiyun; Chen, Xue; Zhao, Xin; Zhang, Cheng; Zhang, Xiangkun; Yin, Xiaobin; Wu, Ji
Subjects: Geosciences >> Space Physics

Sea surface salinity (SSS) plays an important role in global water cycle. In recent years, satellite based remote sensing has proven to be a promising approach for global SSS observation. A new payload concept, named MICAP (microwave imager combined active and passive), has been introduced in this paper. MICAP is a suit of active/passive instrument package, which includes L/C/K band one-dimensional MIR (microwave interferometric radiometer) and L-band DBF (digital beamforming) scatterometer, sharing a parabolic cylinder reflector. MICAP has been selected to be a candidate payload for future Chinese ocean salinity mission. In this paper, the MICAP instrument concept, specification and preliminary system design will be introduced.

submitted time 2016-05-03 Hits449Downloads317 Comment 0

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