FORCE can download Landsat and Sentinel-2 data from cloud storage providers (currently Google Cloud Storage).
force-level1-csd allows to search for image acquisitions that precisely match the user’s requirements, manages data pool, and prepares/updates the file queue required for level 2 procesing.
If you need to bypass
force-level1-csd, it is recommended to store the images in a consistent data pool without duplicates.
You will need to prepare a File queue.
Before you start:
The metadata catalogues need to be downloaded prior to the first run and downloading Sentinel-2 data requires authentication.
See the Level 1 Cloud Storage Downloader tutorial for more information on properly setting up
force-level1-csd requires four mandatory arguments to be specified.
Several optional arguments can be used to further refine the search.
Usage: force-level1-csd [optional arguments] metadata-dir level-1-datapool queue aoi
metadata-dirThe directory where the metadata catalogues (csv files) are stored.They need to be downloaded before the first use and should be updated regularly.
level-1-datapoolAll downloaded files are stored in the data pool, which should be an existing directory.Scenes will not be downloaded if they already exist in this folder.
queueDownloaded files are appended to a file queue, which is needed for the Level 2 processing.The file doesn’t need to exist.If it does exist, new lines will be appended on successful ingestion.This queue is needed for Level 2 processing.All images with
QUEUEDstatus will be processed, then set to
area of interestThe area that data should be downloaded for. It can be defined in three different ways(1) user-supplied coordinates of your study area:The polygon must be closed (first
X/Ymust be given asdecimal degrees with negative values for West and South coordinates.Either specify the path to a file, or the coordinates on the command line.If in a file, provide one coordinate per line.If on the command line, provide a comma separated list.(2) a shapefile (point/polygon/line). On-the-fly reprojection is provided,but using EPSG4326 is recommended.(3) scene identifier:Landsat: Path/Row as
PPPRRR. Make sure to keep leading zeros:correct: 181034, incorrect: 18134Sentinel-2: MGRS tile as
TXXXXX. Make sure to keep the leading
Tbefore the MGRS tile number.You can either give the path to a file, or give the IDs on the command line.If in a file, provide one ID per line.If on the command line, provide a comma separated list.
Running the search without any optional parameters will return all Landsat and Sentinel-2 scenes for the specified
To narrow down the search results, use the following parameters.
- -c | --cloudcover
minimum,maximumThe cloud cover range must be specified in %Default:
- -d | --daterange
starttime,endtimeDates must be given in the following format: YYYYMMDD,YYYYMMDDDefault:
- -s | --sensor
- Sensors to include in the query, comma-separated.Valid sensors:Landsat
LT04- Landsat 4 TM
LT05- Landsat 5 TM
LE07- Landsat 7 ETM+
LC08- Landsat 8 OLISentinel
S2A- Sentinel-2A MSI
S2B- Sentinel-2B MSIDefault:
- -t | --tier
- Landsat collection tier level. Valid tiers:
The remaining optional arguments are used to perform a search without actually downloading data, store the metadata of search results, and download / update the metadata catalogues.
- -n | --no-act
- Will trigger a dry run that will only return the number of imagesand their total data volume
- -k | --keep-meta
- Will write the results of the query to the level 1 datapool directory.Two files will be created if Landsat and Sentinel-2 data is queriedat the same time. Filename:
[satellite]refers to either Landsat or Sentinel-2.
- -l | --logs
- Check for FORCE Level-2 log files and remove any products from the searchthat have been processed previously. Note that this only checks for thepresence of log files, not for actual Level-2 products.
- -u | --update
- Will create or the metadata catalogue (download and extract from GCS)If this option is used, only one mandatory argument is expected (metadata-dir).Use the -s option to only update Landsat or Sentinel-2 metadata.
The mandatory arguments are positional!
They need to be provided in this exact order.
The optional arguments can be placed anywhere and may also be combined.
-n -k -c 0,70 could also be written as
When values are passed to the optional arguments (cloud cover, date range, sensor, or tier), these must be separated by commas
, and must not contain whitespace.
To learn more about FORCE Level 1 CSD, check the Level 1 Cloud Storage Downloader tutorial. It covers the set up, usage, and provides some more general information.