Spatial Data Processing

Overview

Geospatial Data Processing takes advantage of the OGC Web Processing Service (WPS) as web interface to allow for the dynamic deployment of user processes. In this case, Terradue selected the 52° North WPS open source component, as the interface to a Cloud service that we developed to allow the deployment of user “algorithms”. We demonstrate that such user algorithms can be developed to exploit the powerful and distributed framework offered by Apache™ Hadoop™ MapReduce. The source code for wrappers and examples developed by Terradue are contributed via the iMarine EC FP7 project to the D4Science gCube infrastructure components.

Thus was born WPS-Hadoop.

Key Features

WPS-Hadoop offers a web interface to access the algorithms from external HTTP clients through three different kind of requests, made available through the Web Processing Standard interface:

• The GetCapabilities operation provides access to general information about a live WPS implementation, and lists the operations and access methods supported by that implementation. 52N WPS supports the GetCapabilities operation via HTTP GET and POST.

• The DescribeProcess operation allows WPS clients to request a full description of one or more processes that can be executed by the service. This description includes the input and output parameters and formats and can be used to automatically build a user interface to capture the parameter values to be used to execute a process.

• The Execute operation allows WPS clients to run a specified process implemented by the server, using the input parameter values provided and returning the output values produced. Inputs can be included directly in the Execute request, or reference web accessible resources.