气象卫星仪器使用的光谱中只有微波观测可以部分穿过云区,常被用来反演地表温度、海表温度等重要的地表参数.近年来随着地面通信等主动微波技术的发展和商业服务中对微波波段的使用日益增多,被动接收来自地球-大气系统辐射的星载微波仪...气象卫星仪器使用的光谱中只有微波观测可以部分穿过云区,常被用来反演地表温度、海表温度等重要的地表参数.近年来随着地面通信等主动微波技术的发展和商业服务中对微波波段的使用日益增多,被动接收来自地球-大气系统辐射的星载微波仪器观测越来越受到主动微波发射的影响,尤其是在低频波段遥感探测量中增加了不可预测的噪声,造成观测亮度温度相比视场内来自自然大气和地表发射、散射辐射而言异常偏大,进而使反演的地表参数和资料同化的分析场具有较大偏差.卫星微波接收的来自地气系统的被动热辐射与主动传感器发射的信号相混合,被称为无线电频率干扰(radio-frequency interference,RFI);星载微波辐射计接收的辐射测量受地表反射的静止电视或通信卫星下行信号干扰,称之为电视频率干扰(TV frequency interference,TFI).如果不正确识别和去除污染资料,将大大降低星载被动微波仪器的科学价值.本文总结了谱差法、主成分分析法、平均值标准差法、模拟差法等几种常用的RFI软件识别算法,以及谱差比值法、SE法等几种较新的识别算法,并对各种算法的适用范围及优缺点进行了评述.同时详细介绍了源自反射的静止电视或通信卫星下行信号对星载微波观测造成污染的特征及识别、订正方法.展开更多
Full duplex radio increases the frequency efficiency but its performance is limited by the self-interference （SI）. We first analyze the multiple noises in the full duplex radio system and model such noises as an α ...Full duplex radio increases the frequency efficiency but its performance is limited by the self-interference （SI）. We first analyze the multiple noises in the full duplex radio system and model such noises as an α - stable distribution. Then we formulate a novel non-Gaussian SI problem. Under the maximum correntropy criterion （MCC）, a robust digital non-linear self-interference cancellation algorithm is proposed for the SI channel estimation. A gradient descent based algorithm is derived to search the optimal solution. Simulation results show that the proposed algorithm can achieve a smaller estimation error and a higher pseudo signal to interference plus noise ratio （PSINR） than the well-known least mean square （LMS） algorithm and least square （LS） algorithm.展开更多
文摘气象卫星仪器使用的光谱中只有微波观测可以部分穿过云区,常被用来反演地表温度、海表温度等重要的地表参数.近年来随着地面通信等主动微波技术的发展和商业服务中对微波波段的使用日益增多,被动接收来自地球-大气系统辐射的星载微波仪器观测越来越受到主动微波发射的影响,尤其是在低频波段遥感探测量中增加了不可预测的噪声,造成观测亮度温度相比视场内来自自然大气和地表发射、散射辐射而言异常偏大,进而使反演的地表参数和资料同化的分析场具有较大偏差.卫星微波接收的来自地气系统的被动热辐射与主动传感器发射的信号相混合,被称为无线电频率干扰(radio-frequency interference,RFI);星载微波辐射计接收的辐射测量受地表反射的静止电视或通信卫星下行信号干扰,称之为电视频率干扰(TV frequency interference,TFI).如果不正确识别和去除污染资料,将大大降低星载被动微波仪器的科学价值.本文总结了谱差法、主成分分析法、平均值标准差法、模拟差法等几种常用的RFI软件识别算法,以及谱差比值法、SE法等几种较新的识别算法,并对各种算法的适用范围及优缺点进行了评述.同时详细介绍了源自反射的静止电视或通信卫星下行信号对星载微波观测造成污染的特征及识别、订正方法.
基金supported by the National Natural Science Foundation of China under Grants 61372092"863" Program under Grants 2014AA01A701
文摘Full duplex radio increases the frequency efficiency but its performance is limited by the self-interference （SI）. We first analyze the multiple noises in the full duplex radio system and model such noises as an α - stable distribution. Then we formulate a novel non-Gaussian SI problem. Under the maximum correntropy criterion （MCC）, a robust digital non-linear self-interference cancellation algorithm is proposed for the SI channel estimation. A gradient descent based algorithm is derived to search the optimal solution. Simulation results show that the proposed algorithm can achieve a smaller estimation error and a higher pseudo signal to interference plus noise ratio （PSINR） than the well-known least mean square （LMS） algorithm and least square （LS） algorithm.
