Although the easiest way to set-up and launch a processing chain is probably by setting parameters with the GUI and launching it right away, it is often very useful to be able to launch a processing from the command line without opening the GUI.
This allows using sen2r functionalities (provided both by the main function
sen2r() or other package functions) as part of more complex scripts, or scheduling a processing so to automatically update a time series of S2 products.
Three main processing modes are available:
In this case, the user is expected to specify all arguments required for processing within the call to
sen2r() documentation for a detailed description of each option – note that unspecified arguments will be set to default values, when possible).
For example, the following code chunk would perform the following operations:
barbellino.geojsonspatial file between 1 and 15 July 2019;
"cloud_and_shadow", in this case) shows that less than 10% of the area of interest was covered by clouds;
# Set paths out_dir_1 <- tempfile(pattern = "sen2r_out_1_") # output folder safe_dir_1 <- tempfile(pattern = "sen2r_safe_") # folder to store downloaded SAFE myextent_1 <- system.file("extdata/vector/barbellino.geojson", package = "sen2r") library(sen2r) out_paths_1 <- sen2r( gui = FALSE, step_atmcorr = "l2a", extent = myextent_1, extent_name = "Barbellino", timewindow = c(as.Date("2019-07-13"), as.Date("2019-07-25")), list_prods = c("BOA","SCL"), list_indices = c("NDVI","MSAVI2"), list_rgb = c("RGB432B"), mask_type = "cloud_and_shadow", max_mask = 10, path_l2a = safe_dir, path_out = out_dir_1 )
[2020-02-05 10:53:53] #### Starting sen2r execution. #### [2020-02-05 10:53:57] Searching for available SAFE products on SciHub... [2020-02-05 10:54:02] Computing output names... [2020-02-05 10:54:03] Processing group 1 of 5... [2020-02-05 10:54:03] Starting to download the required level-2A SAFE products. [2020-02-05 10:54:03] Check if products are available for download... [2020-02-05 10:54:03] 1 Sentinel-2 images are already online. [2020-02-05 10:54:03] Downloading Sentinel-2 image 1 of 1 (S2A_MSIL2A_20190703T101031_N0212_R022_T32TNS_20190703T134349.SAFE)... [2020-02-05 10:54:41] Download of level-2A SAFE products terminated. # (skipping most processing messages here)
After subsequent messages describing the processing operations which are being done, a report summarising the conducted processing is issued at the end:
╔══════════════════════════════════════════════════════════════════════════════ ║ sen2r Processing Report ╟────────────────────────────────────────────────────────────────────────────── ║ Dates to be processed based on processing parameters: 5 ║ Processing completed for: all expected dates. ║ Outputs for: 2 out of 5 expected dates not created because cloudiness over ║ the spatial extent is above 10%. ╚══════════════════════════════════════════════════════════════════════════════ [2020-02-05 11:02:53] #### Execution of sen2r session terminated. #### The processing chain can be re-launched with the command: sen2r("/home/lb/.sen2r/proc_par/s2proc_20200205_105355.json")
In this case, it shows that all the 5 S2 images satisfying the spatial-temporal query were downloaded and properly processed. However, outputs for two of those dates were not created because cloudiness over the spatial extent was above the specified threshold.
S2 original SAFE images are stored in the folder specified by
safe_dir, and are not deleted after processing (unless the user sets also the argument
 "S2A_MSIL2A_20190703T101031_N0212_R022_T32TNS_20190703T134349.SAFE"  "S2A_MSIL2A_20190706T102031_N0212_R065_T32TNS_20190706T134618.SAFE"  "S2A_MSIL2A_20190713T101031_N0213_R022_T32TNS_20190713T135651.SAFE"  "S2B_MSIL2A_20190708T101039_N0213_R022_T32TNS_20190708T133715.SAFE"  "S2B_MSIL2A_20190711T102029_N0213_R065_T32TNS_20190711T135545.SAFE"
Outputs are automatically subsetted and masked over the study area, and stored in appropriate subfolders of
 "BOA" "MSAVI2" "NDVI" "RGB432B" "SCL"
 "S2A2A_20190703_022_Barbellino_NDVI_10.tif"  "S2A2A_20190706_065_Barbellino_NDVI_10.tif"  "S2B2A_20190708_022_Barbellino_NDVI_10.tif" "thumbnails"
Users can set the desired parameters with the GUI, export them to a JSON file and run the command
sen2r() specifying the JSON path in the argument
param_list to specify processing options. For example, the command would launch
sen2r() using settings specified in file
"file30ac6089ea3_sen2r_params.json" in the reproducible case):
[2020-02-05 11:58:09] #### Starting sen2r execution. #### [2020-02-05 11:58:09] Searching for available SAFE products on SciHub... [2020-02-05 11:58:12] Computing output names... [2020-02-05 11:58:13] Starting to download the required level-2A SAFE products. Images S2A_MSIL2A_20170703T101021_N0205_R022_T32TNS_20170703T101041.SAFE are already on your system and will be skipped. Set "overwrite_safe" to TRUE to re-download them. # (skipping most processing messages here) ╔══════════════════════════════════════════════════════════════════════════════ ║ sen2r Processing Report ╟────────────────────────────────────────────────────────────────────────────── ║ Dates to be processed based on processing parameters: 1 ║ Processing completed for: all expected dates. ╚══════════════════════════════════════════════════════════════════════════════ [2020-02-05 11:58:20] #### Execution of sen2r session terminated. #### The processing chain can be re-launched with the command: sen2r("/home/lb/.sen2r/proc_par/s2proc_20200205_115809.json")
This is for example particularly useful if a
sen2r() processing requires ordering images from the LTA archive (see https://scihub.copernicus.eu/userguide/LongTermArchive).
The user can in fact, in that case:
sen2r()will process all already online dates, and automatically order the missing ones;
This allows users to use a previously saved JSON file as a “template” for a processing, but changing “manually” any desired parameter.
For example, the following instructions would execute the same processing as in the previous example, but changing both the extent and time window of the analysis.
out_dir_3 <- tempfile(pattern = "sen2r_out_3_") # new output folder myextent_3 <- system.file("extdata/vector/scalve.kml", package = "sen2r") out_paths_3 <- sen2r( param_list = json_path_2, extent = myextent_3, extent_name = "newxtent", timewindow = c(as.Date("2019-01-01"), as.Date("2019-01-30")), path_out = out_dir_3 )
This allows for example to easily run the same processing over different spatial/temporal extents.