Effects of spectral response function on surface reflectance and NDVI measured with moderate resolution satellite sensors

2002 ◽  
Author(s):  
A Trishchenko ◽  
J Cihlar ◽  
Z Li
2010 ◽  
Vol 3 (4) ◽  
pp. 3277-3291 ◽  
Author(s):  
B. J. Sohn ◽  
B.-R. Kim ◽  
S.-S. Lee

Abstract. The calibration of the Moderate-resolution Imaging Spectroradiometer (MODIS) 6.8 μm water vapor (WV) channel was assessed by comparing Terra/MODIS measurements with the WV channel brightness temperatures equivalent to Infrared Atmospheric Sounding Interferometer (IASI) measurements for June 2007 and December 2007. IASI spectral information was transferred to the Japanese Multifunctional Transport Satellite (MTSAT)-1R WV channel and then to the MODIS WV channel. Results indicate that the MODIS WV channel is biased low up to 3 K, likely caused by the shift of the spectral response function by about +11 cm−1. This finding is particularly important because the bias of −3 K can cause about +30% relative errors in the retrieval of upper tropospheric humidity (UTH). In other words, the current MODIS measurements may result in higher UTH values, showing relative errors up to +30%.


2010 ◽  
Vol 3 (6) ◽  
pp. 1667-1672 ◽  
Author(s):  
B. J. Sohn ◽  
B.-R. Kim ◽  
S.-S. Lee

Abstract. The calibration of the Moderate-resolution Imaging Spectroradiometer (MODIS) 6.8 μm water vapor (WV) channel was assessed by comparing Terra/MODIS measurements with the WV channel brightness temperatures equivalent to Infrared Atmospheric Sounding Interferometer (IASI) measurements for June 2007 and December 2007. IASI spectral information was transferred to the Japanese Multifunctional Transport Satellite (MTSAT)-1R WV channel and then to the MODIS WV channel. Results indicate that the MODIS WV channel is biased low by 2–3 K, possibly caused by the shift of the spectral response function by about +11 cm−1. This finding is particularly important because the bias of −3 K can cause about +30% relative errors in the retrieval of upper tropospheric humidity (UTH) over the tropics. In other words, the current MODIS measurements may result in higher UTH values, showing relative errors up to +30%.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Simon Plank ◽  
Francesco Marchese ◽  
Nicola Genzano ◽  
Michael Nolde ◽  
Sandro Martinis

AbstractSatellite-based Earth observation plays a key role for monitoring volcanoes, especially those which are located in remote areas and which very often are not observed by a terrestrial monitoring network. In our study we jointly analyzed data from thermal (Moderate Resolution Imaging Spectrometer MODIS and Visible Infrared Imaging Radiometer Suite VIIRS), optical (Operational Land Imager and Multispectral Instrument) and synthetic aperture radar (SAR) (Sentinel-1 and TerraSAR-X) satellite sensors to investigate the mid-October 2019 surtseyan eruption at Late’iki Volcano, located on the Tonga Volcanic Arc. During the eruption, the remains of an older volcanic island formed in 1995 collapsed and a new volcanic island, called New Late’iki was formed. After the 12 days long lasting eruption, we observed a rapid change of the island’s shape and size, and an erosion of this newly formed volcanic island, which was reclaimed by the ocean two months after the eruption ceased. This fast erosion of New Late’iki Island is in strong contrast to the over 25 years long survival of the volcanic island formed in 1995.


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