Influence of surface reflectivity variability on MOPITT 2.2-2.3 /spl mu/m channel radiances and the retrieval of CO and CH/sub 4

• Published in: IEEE International Geoscience and Remote Sensing Symposium Vol. 2; pp. 1094 - 1096 vol.2
• Main Authors: Francis, G.L., Gille, J.C., Edwards, D.P., Ziskin, D.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 2002
• Subjects: Data acquisition; Instruments; Layout; Pollution measurement; Reflectivity; Solar radiation; Spectroscopy; Surface contamination; Surface waves; Terrestrial atmosphere
• ISBN: 9780780375369; 078037536X
• DOI: 10.1109/IGARSS.2002.1025786

The MOPITT (Measurement of Pollution in the Troposphere) instrument uses gas-correlation spectroscopy to retrieve the tropospheric profile of CO and the total column of CO and CH/sub 4/. The instrument's 2.2-2.3 /spl mu/m channel signals can be used to determine the CH/sub 4/ and CO columns. At these wavelengths, surface effects are important since the channel radiances are determined by reflected solar radiation. Small changes in scene during data acquisition for a given pixel can introduce important variations in surface reflectivity, even when averaged over the instrument field-of-view. These variations must be carefully accounted for to ensure a quality column retrieval. MOPITT simulations based on reflectivity measurements from the MODIS Airborne Simulator are used to construct examples illustrating these effects, along with a method for their mitigation.