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Main Concepts

Get familiar with the main concepts associated with workflows.


Introduction

A workflow is a Directed Acyclic Graph (DAG) of data and processing blocks. The workflow defines the order in which each operation associated with a certain block is performed. A workflow always starts with a data block and is followed by one or more processing blocks. A workflow cannot be empty and it needs to contain at least one data block.

The Workflow Pipeline

The workflow pipeline allows you to add a sequence of data and processing blocks that have the role of workflow tasks. The combination of blocks is limited, which means that a block can only be connected to certain other blocks. These constraints are called block capabilities, which define the order of the blocks and dictate which blocks match by specifying the parameter values necessary to allow the combination of blocks: spectral or spatial resolution, file format, bit depth etc.

Workflow Pipeline
Workflow Pipeline

Create a Workflow

The first step is to click on Create Workflow.

Create Workflow
Create Workflow

An empty workflow template appears.

Empty Workflow Template
Empty Workflow Template

Add a data block.

After the data block, click on the plus sign and add a processing block. The blocks that do not match your previous block are grayed out.

After you added the data and processing blocks, your workflow is ready to be configured as a job. A job is a unique instance of a workflow that runs in order to generate the geospatial outputs corresponding to each block and defined by the job parameters.

Click on Save & Configure Job.

Workflow Examples

Workflow with One Block

The first workflow consists of one data block, which allows the users to directly download the dataset Pléiades Reflectance (Download).

Workflow with one data block
Workflow with one data block

Workflow with 3 blocks

The second workflow consists of one data block and 2 processing blocks, which allows the users to download the image, pan-sharpen the image to make it analysis-ready, then analyze it using the vegetation health index NDVI.

Workflow with one data block and 2 processing blocks
Workflow with one data block and 2 processing blocks

Workflow with 5 blocks

The third workflow consists of one data block and 4 processing blocks, which allows the users to download the image, convert the image to the appropriate file format, reproject it to another coordinate system, clip it into smaller tiles, then extract the cars using the Car Detection.

Workflow with one data block and 4 processing blocks
Workflow with one data block and 4 processing blocks

After creating the workflow, configure the job by following the steps from Job Configuration.