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Optical Instrument Structural Design
Published in Paul Yoder, Daniel Vukobratovich, Opto-Mechanical Systems Design, 2017
The Multi-angle Imaging Spectroradiometer (MISR) is a NASA space payload launched aboard the EOS-TERRA spacecraft in December 1999. The science goals were to monitor global atmospheric particulates, cloud movements, surface BRDF (bi-directional reflectance function, a measure of scattering), and vegetative changes on the day-lit side of the Earth during a nominal 6-year mission in polar orbit. Ford et al. (1999) indicated that it employed nine cameras to collect data in four spectral bands within the 0.440−0.880 μm spectral region at nine different angles ranging from 0° to 70.5° along the flight path. Data from each observed point on the Earth were compared for similarities and differences. Key design requirements included an operational temperature range of 0°C–10°C, survival of −40°C to +80°C temperature extremes, ability to withstand launch accelerations, and minimizing long-term light transmission losses in the Earth’s polar radiation environment.
In-Flight Calibration Design
Published in Shen-En Qian, Hyperspectral Satellites and System Design, 2020
Determining the uncertainty in the expected reflectance of the SD has proven to be difficult as the quoted values vary wildly. For example, the Multi-Angle Imaging Spectroradiometer (MISR) is a scientific instrument on the Terra satellite launched by NASA on December 18, 1999. The MISR tests reported uncertainties in the determination of the bidirectional reflectance factor (BRF) of its Spectralon panel as 2.9% absolute and 1.4% relative uncertainties (Bruegge et al. 2001).
Influence of observation angle change on satellite retrieval of aerosol optical depth
Published in Tellus B: Chemical and Physical Meteorology, 2021
Lijuan Chen, Ren Wang, Jiamei Han, Yong Zha
Use of multi-angles is the popular trends for remote sensing sensors in acquiring more detailed and comprehensive observational information. Multi-angle Imaging SpectroRadiometer (MISR) is one instrument that provides remote sensing data for multi-angle observation. It is carried on the Terra satellite and consists of 4 bands and 9 Charge Coupled Device (CCD) cameras, which can provide continuous ground coverage at nine angles. MISR can obtain multi-angle observations at the same location within 7 minutes, which greatly improves the accuracy of retrieval information (Diner et al., 1991; Prasad and Singh, 2007). The MISR aerosol product inversion algorithm strictly selects applicable models from a series of preset models representing global aerosol types. These models include fine-mode aerosol mixtures with different particle size distributions and single scattering albedo, coarse Modal aerosol and non-spherical dust. In order to distinguish the contribution of the surface and the atmosphere from the top layer of the atmosphere, MISR uses an empirical orthogonal function to describe the change of the contribution ratio of the atmosphere and the surface radiation with different observation zenith angles, especially in the bright surface and sandy areas (Garay et al., 2018, 2020). Some existing studies have focussed on aerosol characteristics using MISR multi-band data. For example, Abdou et al. (2005) conducted an comparison between MISR AOD and Moderate resolution Imaging Spectroradiometer (MODIS) AOD and verified the retrieval accuracy using Global Aerosol Robotic Network (AERONET) observations, and the results suggested that on land, MISR AOD is approximately 35% smaller than MODIS AOD in the blue band, while MISR AOD is approximately 10% smaller than MODIS AOD in the red band, and the MISR AOD values are overall close to the AERONET AOD observational values. Through a comparative study of the MISR AOD and AERONET AOD in desert areas, Martonchik et al. (2004) found that MISR can retrieve AOD on the surface with relatively high reflectance of visible light and near infrared bands. Furthermore, Xu et al. (2005) improved the accuracy of retrieving AOD through integrating the radiation and geometric attributes of MODIS and MISR. Wei et al. (2019) proposed a regional robust high-resolution aerosol retrieval algorithm for MODIS images in eastern China. The results show that this algorithm performs well over dark vegetated and bright urban surfaces. Tian et al. (2020) developed a new aerosol retrieval algorithm by considering the effects of surface BRDF using the RossThick-LiSparse model over land for MODIS images. The results show that the retrieved AOD values are highly consistent with AERONET AOD values, the data quality of AOD retrieval has been largely improved compared with those without considering the effects of surface BRDF, especially over bright urban surfaces.