A Comparative Analysis of Low-Level Radio Frequency Interference in SMOS and Aquarius Microwave Radiometer Measurements

ABSTRACTA Giant Meterwave Radio Telescope (GMRT) is being set up at Khodad about 80 km north of Pune in India for operation in the frequency range of about 30 to 1500 MHz. It is to be completed by 1992 and is being designed to investigate many outstanding problems in the fields of galactic and extragalactic astronomy. We present here measurements of man-made radio frequency interference (RFI) conducted at the GMRT site in 1985 and 1988. It is seen that highly sensitive radio astronomy observations can still be made at selected bands in the above frequency range because of the relatively low level of RFI in India. However, this advantage may not remain for more than a decade or two.

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Radio-Frequency Interference Mitigation for the Soil Moisture Active Passive Microwave Radiometer

IEEE Transactions on Geoscience and Remote Sensing ◽

10.1109/tgrs.2013.2281266 ◽

2014 ◽

Vol 52 (1) ◽

pp. 761-775 ◽

Cited By ~ 73

Author(s):

Jeffrey R. Piepmeier ◽

Joel T. Johnson ◽

Priscilla N. Mohammed ◽

Damon Bradley ◽

Christopher Ruf ◽

...

Keyword(s):

Soil Moisture ◽

Radio Frequency ◽

Interference Mitigation ◽

Microwave Radiometer ◽

Passive Microwave ◽

Radio Frequency Interference

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Microwave Radiometer Radio-Frequency Interference Detection Algorithms: A Comparative Study

IEEE Transactions on Geoscience and Remote Sensing ◽

10.1109/tgrs.2009.2031104 ◽

2009 ◽

Vol 47 (11) ◽

pp. 3742-3754 ◽

Cited By ~ 56

Author(s):

Sidharth Misra ◽

Priscilla N. Mohammed ◽

Baris Guner ◽

Christopher S. Ruf ◽

Jeffrey R. Piepmeier ◽

...

Keyword(s):

Comparative Study ◽

Radio Frequency ◽

Microwave Radiometer ◽

Interference Detection ◽

Radio Frequency Interference ◽

Detection Algorithms

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Statistical Approach to Spectrogram Analysis for Radio-Frequency Interference Detection and Mitigation in an L-Band Microwave Radiometer

Sensors ◽

10.3390/s19020306 ◽

2019 ◽

Vol 19 (2) ◽

pp. 306 ◽

Cited By ~ 1

Author(s):

Myeonggeun Oh ◽

Yong-Hoon Kim

Keyword(s):

Radio Frequency ◽

Brightness Temperature ◽

Thermal Emission ◽

Microwave Radiometer ◽

Threshold Level ◽

Maximum Error ◽

Symmetric Distribution ◽

Radio Frequency Interference ◽

Time Frequency ◽

The Mean

For the elimination of radio-frequency interference (RFI) in a passive microwave radiometer, the threshold level is generally calculated from the mean value and standard deviation. However, a serious problem that can arise is an error in the retrieved brightness temperature from a higher threshold level owing to the presence of RFI. In this paper, we propose a method to detect and mitigate RFI contamination using the threshold level from statistical criteria based on a spectrogram technique. Mean and skewness spectrograms are created from a brightness temperature spectrogram by shifting the 2-D window to discriminate the form of the symmetric distribution as a natural thermal emission signal. From the remaining bins of the mean spectrogram eliminated by RFI-flagged bins in the skewness spectrogram for data captured at 0.1-s intervals, two distribution sides are identically created from the left side of the distribution by changing the standard position of the distribution. Simultaneously, kurtosis calculations from these bins for each symmetric distribution are repeatedly performed to determine the retrieved brightness temperature corresponding to the closest kurtosis value of three. The performance is evaluated using experimental data, and the maximum error and root-mean-square error (RMSE) in the retrieved brightness temperature are served to be less than approximately 3 K and 1.7 K, respectively, from a window with a size of 100 × 100 time–frequency bins according to the RFI levels and cases.

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Statistical Approach to Spectrogram Analysis for Radio-Frequency Interference Detection and Mitigation in an L-band Microwave Radiometer

10.20944/preprints201812.0162.v1 ◽

2018 ◽

Author(s):

Myeonggeun Oh ◽

Yong-Hoon Kim

Keyword(s):

Radio Frequency ◽

Brightness Temperature ◽

Thermal Emission ◽

Microwave Radiometer ◽

Threshold Level ◽

Mean Value ◽

Symmetric Distribution ◽

Radio Frequency Interference ◽

Time Frequency ◽

The Mean

For the elimination of radio-frequency interference (RFI) in a passive microwave radiometer, the threshold level is generally calculated from the mean value and standard deviation. However, a serious problem that can arise is an error in the retrieved brightness temperature from a higher threshold level owing to the presence of RFI. In this paper, we propose a method to detect and mitigate RFI contamination using the threshold level from statistical criteria based on a spectrogram technique. Mean and skewness spectrograms are created from a brightness temperature spectrogram by shifting the 2-D window to discriminate the form of the symmetric distribution as a natural thermal emission signal. From the remaining bins of the mean spectrogram eliminated by RFI-flagged bins in the skewness spectrogram for data captured at 0.1-s intervals, two distribution sides are identically created from the left side of the distribution by changing the standard position of the distribution. Simultaneously, kurtosis calculations from these bins for each symmetric distribution are repeatedly performed to determine the retrieved brightness temperature corresponding to the closest kurtosis value of three. The performance is evaluated using experimental data, and the error in the retrieved brightness temperature is observed to be less than approximately 3 K from a window with a size of 100 × 100 time-frequency bins according to the RFI levels and cases.

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