R. Suresh (NASA/MTECH) Ben Burford (JAXA) Bernhard Buckl (DLR) Contact: - CEOS WGISS Meeting, Beijing, China, September 2004 A RSS based CEOP Metadata Prototype System

Background RSS Technology RSS based CEOP Metadata System Demonstration Outline

Background CEOP Metadata discussion and Implementation Plan Semantic Web Activities for Earth Science CEOP In situ Data and Metadata Partners: JAXA, NASA and DLR Demonstration

What is an RSS? RSS is a Web content syndication format. Its name is an acronym for R eally S imple S yndication. RSS is a mechanism for metadata/data providers to let users know what new content is available RSS RSS is a dialect of XML. All RSS files must conform to the XML 1.0 specification as published on the World Wide Web Consortium (W3C) website. The RSS has multiple versions. Current version is 2.0.

RSS feeds include site tracking by search engines and other software. Receive customized information from various sources. RSS feed is machine-readable Continuous real time update of information RSS feed applications

RSS Applications Oceanographer can select only ocean related metadata to be delivered to his desktop. A person interested in Disaster data can get only metadata related to disaster data. A user interested in weather monitoring can receive customized US weather data. Other Applications News Sports Entertainment Job Listings Document cataloging

RSS Feeders and Readers Creation of RSS based system is simple. It involves two steps 1. Generation of RSS feeds: Metadata/data providers can describe metadata using RSS format Metadata can be aggregated for different disciplines : Ocean, Atmosphere, and Solid Earth or locations of stations in case of In situ metadata 2. Users can download RSS readers and install on their system These readers check various sites for RSS feeds and updates information. Users can set up the frequency of update and select the data they want.

At the top level, a RSS document is a element, with a mandatory attribute called version, that specifies the version of RSS that the document conforms to. If it conforms to this specification, the version attribute must be 2.0. Subordinate to the element is a single element, which contains information about the channel (metadata) and its contents. RSS Feed Description

Identify required and optional sub-elements of Required channel elements: Title: The name of the channel. It's how people refer to your service. If you have an HTML website that contains the same information as your RSS file, the title of your channel should be the same as the title of your website. Link: The URL to the HTML website corresponding to the channel. Description: Phrase or sentence describing the channel. Item: A channel may contain any number of s RSS Feed Description

Optional channel elements: language: The language the channel is written in. pubDate: The publication date for the content in the channel. lastBuildDate: The last time the content of the channel changed. ttl: ttl stands for time to live. It's a number of minutes that indicates how long a channel can be cached before refreshing from the source. Image Specifies a GIF, JPEG or PNG image that can be displayed with the channel. and … RSS Feed Description

Elements Description Title The title of the item. Link The URL of the item. Description The item synopsis. Author address of the Author PubDate Indicates when the item was published. Source The RSS channel that the item came from RSS Feed Description-Item

Earth Invaded The earth was attacked by an invasion fleet from halfway across the galaxy; luckily, a fatal miscalculation of scale resulted in the entire armada being eaten by a small dog. Additionally, the feed itself can have metadata associated with it, so that it can be given a title (e.g., "Bob's news headlines"), description, and other fields like publisher and copyright terms. RSS Feed example

CEOP RSS Implementation plan Creating an RSS feed for In situ metadata/data Create, reuse or Modify RSS reader Create Distributed sites Place RSS feed examples on distributed servers (JAXA, DLR, NASA) Users can install RSS readers which will assist them in obtaining real time updates for metadata/data RSS feeds for CEOP applications

NASA Feed DLR Feed JAXA Feed Earth Science Gateway Portal User RSS Reader CEOP Metadata System Architecture

Automatic update of metadata Aggregation of metadata parameters Show me all sites which have data for this time period? Specify update intervals i.e., once a day, hourly, … Provides links to sources of data No processing of data currently Simply display mechanism for updates Give me the maximum temperature for this site for the last month. CEOP In Situ Metadata Implementation FEATURES

RSS Feeder Tools Tools for generating RSS Feeds thelocust.org/projects/instantrss/// Feed Validator

RSS Readers RSS readersReference sites AWASUwww.awasu.com BLOGLINESwww.bloglines.com My Yahoo My.yahoo.com Radio UserlandRadiouserland.com WinRSS Pluck