Interoperapedia

Interoperapedia is the Interoperability Encyclopedia. It is a community resource that collates a base set of materials that the ESIP Federation and its members may use in performing interoperability standards outreach to partner and external organizations and groups. The successful expansion in the use of Earth Science interoperability standards would benefit the entire community of Earth Science data and information users through the reduction in the barriers to the use and distribution of Earth Science products. This project was sponsored by the ESIP Federation’s Information Technology and Interoperability Committee, with the work being performed by Innovim.

Interoperapedia includes the following:

an overview of key Earth Science interoperability standards
- OGC: WxS, CSW, SOS
- OpenDAP
- Semantic Technologies
- Metadata: FGDC, ISO 19115 and related standards
case studies that illustrate the benefits of using interoperability standards
information about computing platforms that may be used to implement and use standards-based Earth Science products

Background

Definition of Interoperability

“The capability to communicate, execute programs, or transfer data among various functional units in a manner that requires the user to have little or no knowledge of the unique characteristics of those units.” According to ISO/IEC 2382-01, Information Technology Vocabulary, Fundamental Terms

The IEEE (Institute of Electrical and Electronics Engineers) defines interoperability as: “the ability of two or more systems or components to exchange information and to use the information that has been exchanged.”

Types of Interoperability

Syntactic Interoperability

If two or more systems are capable of communicating and exchanging data, they are exhibiting syntactic interoperability. Specified data formats, communication protocols and the like are fundamental. In general, XML or SQL standards provide syntactic interoperability. This is also true for lower-level data formats, such as ensuring alphabetical characters are stored in ASCII format in both of the communicating systems.”

Syntactical interoperability is a necessary condition for further interoperability.

Semantic Interoperability

Beyond the ability of two or more computer systems to exchange information, semantic interoperability is the ability to automatically interpret the information exchanged meaningfully and accurately in order to produce useful results as defined by the end users of both systems. To achieve semantic interoperability, both sides must defer to a common information exchange reference model. The content of the information exchange requests are unambiguously defined: what is sent is the same as what is understood.

Approaches to Interoperability

There are two approaches: Build a new system which may incur higher cost or utilize the pre-existing legacy system and bring it up to speed. Regardless of which path is selected, both require: A service-oriented approach that underlies much of today’s World Wide Web. New systems shall use a service-oriented approach to making their data available to distributed communities of scientists.

Interoperability by Functionality

Introduction

Data Access

Sensor Observation Service and SensorML

SOS Concept

SensorML

The OpenGIS® Sensor Model Language Encoding Standard (SensorML) specifies models and XML encoding that provide a framework within which the geometric, dynamic, and observational characteristics of sensors and sensor systems can be defined.

The Objective of SensorML is to provide a complete description of an instrument’s capabilities and give the information needed to process and geolocate the measured data.

SensorML information includes:

Sensor name, type, and identification numbers
Temporal, legal, or classification constraints
A reference to the platform description
The sensor’s coordinate reference system definition
The sensor’s location
The response characteristics and information for geolocating samples
The sensor operator and tasking services
Textual metadata and history of the sensor
Textual metadata and history of the sensor description document

By describing sensors using SensorML, anyone can put sensors or sensor data online for others to find and use.

By automating the reading of metadata, SensorML will enable the development of software tools that automatically co-register different kinds of data with little human intervention.

SensorML makes sensors become more intelligent and autonomous by assisting in onboard processing of data and communications among multiple sensors.

References

http://www.opengeospatial.org/standards/sensorml

Web Map Service (WMS)

OGC WMS standards serve visualizations of geographical data in “flat” map-like layered images.

HTTP queries a WMS server and returns pre-rendered images from different sources.
The returned images from different sources can be layered on top of each other.