Landsat 8 OLI
Landsat 8 OLI was launched by an Atlas-V rocket on February 11, 2013, as part of the long-term Earth Observation Systems (EOS) program. The Landsat 8 is a passive multispectral with an optical sensor. The OLI sensor collects data and improves radiometric accuracy throughout a 12-bit dynamic range, enhancing the signal-to-noise ratio. It amounts to 4096 possible gray levels, as opposed to the 256 gray levels of Landsat 1-7, which only include 8-bit sensors. The OLI captures data for two new bands, a coastal/aerosol band (band 1) and a cirrus band (band 9), together with the historical Landsat multispectral band. They scan the electromagnetic spectrum in 11 distinct bands with a geometric resolution of 15-30 m (Figure 2.7). This sensor has the same seven multispectral bands and 30-meter ground resolution as the ETM+7, in blue, green, red, NIR, SWIR-I, and SWIR-II, respectively (Table 2.2). The TIR band has been upgraded to a ground resolution of 100 meters and measured in two gains. The upgrade included a 15-meter resolution panchromatic band between 0.503 and 0.676 m in the visible green-to-blue spectrum (Boettinger et al., 2008).
Figure (2.7): Landsat-8 in the visible and near-infrared (VNIR) and shortwave infrared (SWIR) regions Modified after (Mars, 2018)
Table (2.2): The Landsat 8 OLI sensors with spectral bands
DInSAR
The DInSAR approach depends on the phase difference Q between two SAR images, which is utilized to measure surface deformation. The ALOS-2 (L-band) and Sentinel-1 (C-band) data were collected in ascending and descending orbits. The two SAR images before and after the earthquake were acquired for all data. Given this event's magnitude and depth, SAR data has completely covered surface deformation near and far from the epicenter. The GAMMA software used to process data
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