To generate a composite image from SAR data before and after the massive mudslide, a spatial coregistration procedure is necessary. For this, right click over the name of each new subset product and select Save Product As, rename it if desired, click ok. Now, the new subset products must be converted to BEAM-DIMAP format. To ensure the same spatial coverage for both images, double click on any of the bands (vv or hv) of the second image and start again the “subset processing” as mention above. Go to Raster > Subset, specify the area and parameters of the region of interest as shown in Figure 9. To get the same spatial subset to both images, click on View and select the following menu options: Statusbar, Synchronise Image Cursors and Synchronise Image Views. This processs must be applied for both image. You can select another type of filter according with your expertise however, we recommend using Lee and Frost filters as they are less degrading to the SAR image.Ĭlick on Radar > Geometric > Terrain Correction > Range-Doppler Terrain Correction, and define all “Processing Parameters” according to Figure 7. Select Radar > Speckle Filtering > Single Product Speckle Filter, and set the “Processing Parameters” as shown in Figure 5. This process must be applied for both images. Select Radar > Radiometric > Calibrate, and set the “Processing Parameters”, select all polarizations and select Sigma0 as output band. Select Radar > Apply Orbit File, and then define all parameters according to Figure 2. For this recommended practice, the "apply orbit file" procedure can be optional nevertheless, it's highly recommended to ensure a successful spatial coregistration process. The orbit file provides an accurate position of SAR image and the update of the original metadata of SAR product, the orbit file is automatically downloaded from SNAP software. This process must be applied to both images. Unzip the Sentinel-1 data in your working directory, Open SNAP software and call SAR images by clicking on File > Open Product and then selecting the manifest.safe file.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |