MPIC-OPT-ETQ
MPIC-OPT-EarThQuake is a service based on the CO-REGIS/MPIC library developed by CNRS/EOST (Strasbourg, France) [1], [2] and the MicMac image matching library developed by IGN (Marne-la-Vallée, France) [3]. CO-REGIS (CO-REGIStration of Sentinel-2 and Landsat-8 images) and MPIC (Mutiple Pairwise Image Correlation of image time series) enable the processing of optical image time series for the quantification of Earth surface motion.
MPIC-OPT-ETQ is an on-demand service tailored for quantifying co-seismic deformation from a limited number of images and a few number of parameters which makes it easy to use by non-experts. It comprises two components with (a) an analysis module for measuring sub-pixel displacement from optical image pairs and (b) a correction module for the geometric correction and filtering of residuals.
EO sources:
- Sentinel-2 MSI L1C
Outputss
Four service outputs are provided for visualization on GEP: * Mean displacement magnitude: It consists of a GeoTIFF image representing the mean displacement magnitude over all time steps. The unit is in m. The naming convention is MM_Mean_displ_magnitude_tile_date1_to_dateN.tif * Mean displacement: TIt consists of two GeoTIFF images representing the mean displacement in the E−W and N−S direction. The unit is in m. The naming convention is MM_Mean_displacement_EW_tile_date1_to_dateN.tif and MM_Mean_displacement_NS_tile_date1_to_dateN.tif. * Quality: It consists of a GeoTIFF image representing the percentage, per pixel, of the pairs with a correlation score NCC > minimum correlation threshold.
Four service output folders are provided for download by the user: * Analysis: Folder containing the four products described above in float GeoTIFF file formats. * Displacements: Folder containing the correlation grids and the corrected and filtered displacement field grids.
- Corrected displacement fields for each time step: Float GeoTIFF files representing the measured displacement among the two respective input images in pixels in E-W direction (East is positive) and N-S direction (South is positive) after application of the corrections selected by the user. The naming conventions are MM_EW_displ_tile_date1_vs_date2_corrected.tif and MM_NS_displ_tile_date1_vs_date2_corrected.tif respectively.
- Filtered displacement fields for each time step: Float GeoTIFF files representing the measured displacements among the two respective input images in pixels in E-W direction (East is positive) and N-S direction (South is positive) after filtering. The naming conventions are MM_EW_displ_tile_date1_vs_date2_FILTER_Displmax.tif and MM_NS_displ_tile_date1_vs_date2_FILTER_Displmax.tif respectively.
- Correlation scores: Folder containing 8-bit GeoTIFF images representing the correlation score for each time step with the correlation coefficient [0,1] quantized in the range [128,255]. The naming convention is MM_Corr_tile_date1_date2.tif.
The tutorial introduces the use of the MPIC-OPT-ETQ service for the quantification of co-seismic motion. To this end we will process Sentinel-2 images acquired before and after the Ridgecrest earthquake sequence (California, USA, 2019).
This will display the service panel including several tunable parameters.
The Geobrowser offers multiple ways to search a large variety of EO-based dataset and the user should refer to the Geobrowser section for a general introduction. For this tutorial we will use a data package which is accessible through the “Data Packages” tab on the upper left of the screen. If you type “Ridgecrest” into the search box you should be able to find a data package named “Ridgecrest_2019_S2_2im”. Alternatively you can access the `Ridgecrest data package`_ directly by clicking on the link: .. Ridgecrest datapackage: https://geohazards-tep.eu/t2api/share?url=https%3A%2F%2Fgeohazards-tep.eu%2Ft2api%2Fdata%2Fpackage%2Fsearch%3Fid%3DRidgecrest_2019_S2_2im
Click on the data package, hold Shift and Drag and Drop all four products in the Sentinel-2 products field in the service panel on the right:
Warning
Sentinel-2 datasets distributed before 27 September 2016 contain multiple tiles. For such datasets the Geobrowser currently returns several results including both the original multi-tile dataset and a preview of the footprints of the tiles. For processing, you must select only the original multi-tile datasets. For datasets after 27 September 2016, there is no such ambiguity.
There are 16 processing parameters that can be adjusted. A short explanation of the parameter is provided when hovering over the parameter fields.
Warning
Choosing the Forward+Backward option has to be carefully considered by the user as it increases the number of pairs created and hence, the computing time and resources.
Note
The products in the Geobrowser are previews. The user needs to download the results for further analysis and interpretation.
[1] | (1, 2) Stumpf, A., Malet, J.-P. and Delacourt, C. (2017). Correlation of satellite image time-series for the detection and monitoring of slow-moving landslides. Remote Sensing of Environment, 189: 40-55. DOI:10.1016/j.rse.2016.11.007 |
[2] | (1, 2) Stumpf, A., Michéa, D. Malet, J.-P. (2018). Improved co-registration of Sentinel-2 and Landsat-8 imagery for Earth surface motion measurements. Remote Sensing, 10, 160. DOI:10.3390/rs10020160 |
[3] | Rosu, A.-M., Pierrot-Deseilligny, M., Delorme, A., Binet, R. and Klinger, Y. (2015). Measurement of ground displacement from optical satellite image correlation using the free open-source software MicMac. ISPRS Journal of Photogrammetry and Remote Sensing, 100: 48–59. DOI:10.1016/j.isprsjprs.2014.03.002 |
[4] | Yamazaki D., Ikeshima, D., Tawatari, R., Yamaguchi, T., O’Loughlin, F., Neal, J.-C., Sampson, C.C., Kanae, S., and Bates, P.D. (2017). A high accuracy map of global terrain elevations. Geophysical Research Letters, 44: 5844-5853, DOI:10.1002/2017GL072874 |
[5] | Copernicus Services Coordinated Interface / CSCI (2020). Copernicus DEM - Global and European Digital Elevation Model (COP-DEM). https://spacedata.copernicus.eu/web/cscda/dataset-details?articleId=394198 |
[6] | Provost, F., Michéa, D., Malet J.-P., Stumpf, A., Doin M.-P., Lacroix, P., Boissier, E., Pointal, E., Pacini F., Bally, P. (submitted). Terrain deformation measurements from optical satellite imagery: the MPIC-OPT processing services for geohazards monitoring. Remote Sensing of Environment (subm. in Oct. 2020). |