FY-3D HIRAS Radiometric Calibration and Accuracy Assessment

Wu, Chunqiang; Qi, Chengli; Hu, Xiuqing; Gu, Meng; Yang, Tianhang; Xu, Hanlie; Lee, Lu; Yang, Zhiyong; Zhang, Peng

doi:10.1109/tgrs.2019.2959830

Cited by 27 publications

(15 citation statements)

References 34 publications

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“…A curious point to note here is that one of the few channels to improve (down by −3%) is AMSU‐A channel 14, the highest temperature peaking channel, that suffers the largest degradation in the MO54R907 and NOAA54R812 experiments. It is not clear at this stage what is the reason for the global system degradation and further investigations will be conducted, although it may be related to unresolved calibration issues affecting the detector nonlinearity correction and polarization parameters (Wu et al ., 2020).…”

Section: Resultsmentioning

confidence: 99%

A channel selection for the assimilation of CrIS and HIRAS instruments at full spectral resolution

Carminati

2022

Quart J Royal Meteoro Soc

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A new channel selection is proposed for the processing of observations at full spectral resolution (FSR) from the Cross-track Infrared Sounder (CrIS) and Hyperspectral Infrared Atmospheric Sounder (HIRAS) instruments in the Met Office global numerical weather prediction (NWP) system. The new selection has been derived in order to minimise the error in NWP analysis and has been compared to an existing selection developed at the National Oceanic and Atmospheric Administration (NOAA). Both selections have been tested in the Met Office global NWP system to investigate the use of FSR CrIS compared with the current normal spectral resolution (NSR) set-up employed in operations. Improvements are obtained for most forecast variables up to 7-day lead times, with change in root-mean-square error (RMSE) ranging from 0.13 to 0.54%, although degradation of tropical temperatures are noted for the NOAA selection. The background fit to observations from independent sounders improves by up to 0.8% with the new selection, outperforming the NOAA selection which results in degradations across most instruments. The assimilation of HIRAS observations does not however benefit the system.

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Section: Resultsmentioning

confidence: 99%

A channel selection for the assimilation of CrIS and HIRAS instruments at full spectral resolution

Carminati

2022

Quart J Royal Meteoro Soc

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“…FengYun-3 is a Chinese second-generation sun-synchronous meteorological satellite [28]. HIRAS is the first infrared Fourier detection instrument carried on Fengyun-3D [29]. The main goal is to observe the infrared radiation emitted by the Earth-Atmosphere system with high spectral resolution in the 0.38-15.38 µm spectral range.…”

Section: Data 211 Satellite Datamentioning

confidence: 99%

Temperature and Relative Humidity Profile Retrieval from Fengyun-3D/HIRAS in the Arctic Region

Bao

Liu

et al. 2021

Remote Sensing

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The acquisition of real-time temperature and relative humidity (RH) profiles in the Arctic is of great significance for the study of the Arctic’s climate and Arctic scientific research. However, the operational algorithm of Fengyun-3D only takes into account areas within 60°N, the innovation of this work is that a new technique based on Neural Network (NN) algorithm was proposed, which can retrieve these parameters in real time from the Fengyun-3D Hyperspectral Infrared Radiation Atmospheric Sounding (HIRAS) observations in the Arctic region. Considering the difficulty of obtaining a large amount of actual observation (such as radiosonde) in the Arctic region, collocated ERA5 data from European Centre for Medium-Range Weather Forecasts (ECMWF) and HIRAS observations were used to train the neural networks (NNs). Brightness temperature and training targets were classified using two variables: season (warm season and cold season) and surface type (ocean and land). NNs-based retrievals were compared with ERA5 data and radiosonde observations (RAOBs) independent of the NN training sets. Results showed that (1) the NNs retrievals accuracy is generally higher on warm season and ocean; (2) the root-mean-square error (RMSE) of retrieved profiles is generally slightly higher in the RAOB comparisons than in the ERA5 comparisons, but the variation trend of errors with height is consistent; (3) the retrieved profiles by the NN method are closer to ERA5, comparing with the AIRS products. All the results demonstrated the potential value in time and space of NN algorithm in retrieving temperature and relative humidity profiles of the Arctic region from HIRAS observations under clear-sky conditions. As such, the proposed NN algorithm provides a valuable pathway for retrieving reliably temperature and RH profiles from HIRAS observations in the Arctic region, providing information of practical value in a wide spectrum of practical applications and research investigations alike.All in all, our work has important implications in broadening Fengyun-3D’s operational implementation range from within 60°N to the Arctic region.

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“…Ideally, the FTS measurement is linearly proportional to the incident spectral radiance. However, according to the instrumentation study and data analysis of some existing remote sensing IR FTS, such as MetOp/IASI [8], SNPP/CrIS [9], FY-3D/HIRAS [10], the signal chain nonlinearity is expected to be one dominant source of uncertainty associated with the measured spectra [11][12]. Generally, the measurement directly recorded on a FTS detector is called interferogram, which is converted by the inverse Fourier transform of the incident light spectrum.…”

Section: Introductionmentioning

confidence: 99%

Radiometric nonlinearity and the correction strategies for infrared hyperspectral benchmark sounder

Lee

Qi²,

Ding³

et al. 2023

Earth and Space: From Infrared to Terahertz (ESIT 2022)

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The infrared (IR) benchmark sounder is designed to detect the tiny change of long-term global climate by measuring the spectrally resolved IR radiance emitted from Earth to space with high accuracy. Besides, the IR sounder also serve as a space-borne radiometric reference to convert the international fleet of weather sounders into a climate benchmarking system with excellent global coverage and similar measurement accuracy. In order to achieve high accuracy, the benchmark sounder must be tuned to be a linear response system and be well radiometrically calibrated. So the nonlinearity response in an IR detector signal chain needs to be corrected prior to the linear radiometric calibration. There are some algorithmic approaches being commonly used to correct the nonlinear measurements. These methods use the measured nonlinear interferograms to polynomially fit the corrected linear interferograms, without considering the physical root of non-linearity. However, they work well only when the detector nonlinearity is small. Regarding the large nonlinearity, a correction method is proposed in this paper. It follows the nonlinearity response mechanism of the IR detector, and use the to-be-solved linear interferogram to polynomially fit the measured non-linear interferogram signal formally, and then derive the correction coefficients from the established equations. According to the correction evaluation and methods comparison using the simulated data as proxy measurements, the proposed method is appropriate for both small and large degree of quadratic nonlinearity detectors.

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FY-3D HIRAS Radiometric Calibration and Accuracy Assessment

Cited by 27 publications

References 34 publications

A channel selection for the assimilation of CrIS and HIRAS instruments at full spectral resolution

A channel selection for the assimilation of CrIS and HIRAS instruments at full spectral resolution

Temperature and Relative Humidity Profile Retrieval from Fengyun-3D/HIRAS in the Arctic Region

Radiometric nonlinearity and the correction strategies for infrared hyperspectral benchmark sounder

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