The Analysis-Ready Data (ARD) tiling project generates image tiles based on Landsat scenes processed to Level 2 (surface reflectance and temperature).

The system contains three components:

• tile generation framework (Mesos framework)
• tile generator
• controller

The tiling framework and tile generator are installed into Docker containers to be run in a Mesos cluster, whereas the controller is installed onto a workstation or server with access to the Mesos cluster. All three components interact with shared database tables to store and retrieve information regarding the scenes being processed.

The controller installation takes place on the designated workstation or server, and is conducted as follows:

mkdir build (if not already existing)
cd build
cmake .. -CMAKE_INSTALL_PREFIX:PATH=/usr/local/usgs/ard_tile
make
sudo make install

Verify the version.txt files, and update if necessary:

external/version.txt
ARD_determine_segments_framework/version.txt
ARD_clip/version.txt

Create and deploy the Docker images:

mkdir build (if not already existing)
cd build
cmake ..
make deploy

If you want to test the containers before deployment, run the following in lieu of "make deploy":

make ard-clip
make ard-segment

The framework interacts with the ARD_PROCESSED_SCENES and ARD_UNPROCESSED_SCENES_V tables. The latter is polled for scenes that are ready to add to tiles. Scenes in the former have their processing states updated when queued and have the state reset (to "BLANK") for running or queued scenes when the framework is restarted. New records are inserted into ARD_PROCESSED_SCENES to identify duplicates and completed scenes.

The tile generator updates the scene processing state in ARD_PROCESSED_SCENES, and inserts records into the ARD_COMPLETED_TILES table when tiles are generated. Scenes in adjacent rows for a given acquisition date are found in the INVENTORY.LMD_SCENE table, and scene corner coordinates are read from the SCENE_COORDINATE_MASTER_V table. Input scene locations are retrieved from the ARD_L2_ALBERS_INVENTORY_V table.

The controller polls the ARD_PROCESSED_SCENES table for the number of scenes in the various states of processing (complete, inqueue, inwork, blank), and can also list the product IDs for scenes in these states. It also counts the number of scenes in ARD_UNPROCESSED_SCENES_V that are remaining. If the operator requests a count of the scenes in an error state, ARD_PROCESSED_SCENES is polled for the count of records in "ERROR" or "NOGRID" state.

The controller reports the number of tiles successfully generated by polling the ARD_COMPLETED_TILES table.