Research and implementation of a universal workflow model to evaluate the soil fertility based on OGC Web Service

A method based on workflow technology and Open Geospatial Consortium(OGC)specification is proposed to establish a universal workflow conceptual model in the network environment.In this paper,the soil fertility evaluation conceptual model was developed as an evaluation method of soil fertility by analyzing the GIS-based fertility evaluation method and extracting the dynamic variable to verify the feasibility model.This validation process involves determining the instantiation of the conceptual model.The proposed conceptual model achieved the following goals.All data acquisition and processing functions were packaged into an OGC-compliant service model;these service models were organized into a processing chain in a certain order on the workflow platform by Petri-Net;the fertility evaluation was realized on the workflow platform by calling the processing chain.Results showed that processing functions and data can be shared in the network environment,and the network workflow model can be realized by the workflow technology.The successful implementation of fertility evaluation proved the feasibility of the network-based universal workflow conceptual model.In addition,the flexibility of our modeling method is demonstrated by reconstructing the workflow model.

An asynchronous Geoprocessing Workflow and its application to an Antarctic ozone monitoring and mapping service

The integration of Sensor Web Enablement services with other Open Geospatial Consortium(OGC)Web Services as Geospatial Processing Workflows(GPW)is essential for future Sensor Web application scenarios.With the help of GPW technology,distributed and heterogeneous OGC Web Services can be organized and integrated as compound Web Service applications that can direct complicated earth observation tasks.Under the Sensor Web environment,asynchronous communications between Sensor Web Services are common.We have proposed an asynchronous GPW architecture for the integration of Sensor Web Services into a Web Service Business Process Execution Language workflow technology.We designed a Sensor Information Accessing and Processing workflow,an asynchronous GPW instance,to take an experiment of observing and mapping ozone over Antarctica.Based on our results,our proposed asynchronous workflow method shows the advantages of taking environmental monitoring and mapping tasks.