Analysis Based on Onboard Lamp and Lunar Vicarious Calibrations for Sensitivity Degradation of a Hyperspectral Sensor

Yamamoto, Sakae; Mizuochi, Hiroki; Matsuoka, Moe; Iwao, Koki; Tsuchida, Seigi

doi:10.1109/tgrs.2021.3127163

Cited by 3 publications

(2 citation statements)

References 27 publications

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“…We then calculated the ratio of the measured radiance shifted by a wavelength of ω to the modeled radiance, as shown in Fig. 1(b), where the shifted data were obtained using a cubic spline interpolation according to the method used in [28]. For the case of ω = −1.00, −2.00, −4.00, and −5.00 nm, a concave or convex feature in the wavelength range 1240 ≤ λ ≤ 1280 nm is observed in the radiance ratio, indicating that the shape of Band S1 for the measured radiance is not consistent with that for the modeled radiance.…”

Section: Methods a Atmospheric Correction Methodsmentioning

confidence: 99%

Analysis of Long-Term Variation in Spectral Smile of HISUI Using Atmospheric Absorption Bands

Yamamoto,

Tsuchida,

Urai

et al. 2024

IEEE J. Sel. Top. Appl. Earth Observations Remote Sensing

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This paper reports on the long-term variation of the spectral smile and the full-width at half-maximum (FWHM) of the sensor response function for the Hyperspectral Imager Suite (HISUI) onboard the International Space Station (ISS). HISUI is an optical hyperspectral imager comprising two subsystems: a visible-and-near-infrared (VNIR) system covering 400 to 980 nm and a short-wave infrared (SWIR) system covering 895 to 2481 nm. On the basis of atmospheric corrections for actual observation images, we found that the characteristics of the spectral smile and the FWHM can be classified into five major periods. The results show that the first two transitions of the periods are due to updates of the smile correction table used in HISUI and that the last one is related to the occurrence of vertical stripes in the HISUI images. However, two unexpected changes are observed. One is a sudden increase in the spectral smile in the SWIR data to 2.0-2.1 nm on 30 September 2021, which was just 3 days after the second update of the smile correction table. The other is a sudden improvement on 5 January 2022, showing almost zero spectral smile and a nearly constant FWHM. Because neither sudden change is associated with HISUI or ISS operations/events, the optical and electrical systems of HISUI might exhibit instability, leading to sporadic changes of the spectral smile and FWHM. The findings of this study therefore suggest that, although the post-launch spectral smile correction has been completed, continued long-term evaluation of the spectral stability is important.

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Section: Methods a Atmospheric Correction Methodsmentioning

confidence: 99%

Analysis of Long-Term Variation in Spectral Smile of HISUI Using Atmospheric Absorption Bands

Yamamoto,

Tsuchida,

Urai

et al. 2024

IEEE J. Sel. Top. Appl. Earth Observations Remote Sensing

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“…For example, Fig. 2(b) also shows the radiance ratio for the case of the measured radiance shifted by ω = +0.4 nm (red circles), where we obtained the shifted data using the cubic spline interpolation (see, e.g., [27]). We see that the radiance ratio around λ = 745-785 nm with ω = +0.4 nm becomes nearly flat as compared to that with ω = 0.0 nm.…”

Section: B Evaluation Of the Spectral Smile By Atmospheric Correctionmentioning

confidence: 99%

Initial Analysis of Spectral Smile Calibration of Hyperspectral Imager Suite (HISUI) Using Atmospheric Absorption Bands

Yamamoto

Tsuchida

Urai

et al. 2022

IEEE Trans. Geosci. Remote Sensing

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This paper reports on the initial analysis of spectral smile calibration of the Hyperspectral Imager Suite (HISUI) onboard the International Space Station, which has been continuously acquiring data since September 4, 2020. HISUI is an optical hyperspectral imager consisting of two subsystems: VNIR covering 400 to 980 nm at intervals of 10 nm, and SWIR covering 895 to 2481 nm at 12.5 nm intervals. Based on the atmospheric correction for actual observation images, we assessed cross-track dependences of the wavelength deviation (spectral smile) and the full-width at half-maximum (FWHM) of the HISUI response function. We found that significant spectral smile was observed, with maximum variations of 1.8 nm in VNIR and 4.3-4.5 nm in SWIR. In addition, the cross-track variation of FWHM was observed with maximum variations of 5.0 nm for VNIR and 2.5-3.5 nm for SWIR. We used the results to model the smile functions to update a smile correction table in the internal calibration system of HISUI. Then, we evaluated how the smile functions reduce the spectral smile in the data acquired after the update on September 27, 2021. We confirmed that VNIR showed a nearly flat profile within 0.25 nm with a nearly constant FWHM. For SWIR, although a slight amount of spectral smile and a variation of FWHM were still observed partly due to wavelength dependence in the spectral smile, the spectral smile was reduced to <∼2.2 nm. This study demonstrated that wavelength calibration using actual observation images for ground surfaces is important for the characterization of hyperspectral sensors.

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Using the Moon for On-Orbit Absolute Radiometric Calibration of GaoFen-4 PMS

Cai,

Xu,

Shu

et al. 2024

IEEE Trans. Geosci. Remote Sensing

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Analysis Based on Onboard Lamp and Lunar Vicarious Calibrations for Sensitivity Degradation of a Hyperspectral Sensor

Cited by 3 publications

References 27 publications

Analysis of Long-Term Variation in Spectral Smile of HISUI Using Atmospheric Absorption Bands

Analysis of Long-Term Variation in Spectral Smile of HISUI Using Atmospheric Absorption Bands

Initial Analysis of Spectral Smile Calibration of Hyperspectral Imager Suite (HISUI) Using Atmospheric Absorption Bands

Using the Moon for On-Orbit Absolute Radiometric Calibration of GaoFen-4 PMS

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