# Presentation: 364686

## Using Datacasting to Acquire Only the GHRSST Products You Care Abouthttp://datacasting.jpl.nasa.gov

*Andrew Bingham*
*Bob Deen, Kevin Hussey*
*Tim Stough, Sean McCleese, Ed Armstrong, Alex Cervantes*

*Funded through NASA ROSES/ACCESS Program*

*Presented at the GHRSST Science Team Meeting, Melbourne May 2007*

## Podcasting Metaphor

| Podcasting | Datacasting |
| --- | --- |
| Search for and subscribe to music or video feeds using iTunes | Search for and subscribe to Earth Science data feeds using the Datacasting client |
| Download all files as they become available | Download only relevant files, as they become available (filtering) |
| Manage files in iTunes | Manage files in the Datacasting client |
| Listen to music file or watch video | Visualize data in the client and/or Google Earth |
| Upload to ipod | Ingest data into a science analysis tool |

## Overview 

**Subscribe**
- XML feeds list available files within a data set and are updated as new files are made available
- Feed uses the RSS standard, with extensions that describe
- The **content** of the data for filtering
- The **location** of the file for downloading
- The **format** of the files for data extraction
**Download by Content**
- Files are automatically downloaded to client as they become available
- User-defined filters select which files are downloaded (e.g. only files with high clear sky fraction and/or contains an algae bloom)
- Filters are hierarchical, which gives meaning to the filter selections
**Manage & Visualize**
- Downloaded files are placed in a meaningful (or user-defined) directory structure
- Data are extracted from the file and visualized within the client
- Possible plug-in for viewing data overlays in Google Earth

## System Configuration

- Data provider creates XML feeds and provides access to files using the Datacasting server software
- Users subscribe and download relevant files using the Datacasting client software

## The Datacasting Server

- Simplifies publishing of feeds to the Datacasting/RSS specification
- A set of easy to use, portable, Python based tools for publishing your data
- Text based configuration file specifies location of repository, data format, and other information for the feed
- A single script is tailored to process new data granules for publishing

## The Datacasting Client

- Uses an email reader type interface
- Java based tool designed to work on most platforms
- Subscribes to feeds
- Filters available data files and downloads only what the user needs
- Stores and manages files for later use
- Previews data for interactive selection
- Visualizes data after download

## Rich Metadata

- Filtering is a function of the metadata
- Some metadata are part of the core Datacasting XML specification, e.g.
- Location or Extent
- Acquisition or Start time
- Other metadata can be defined by the data provider and included in the XML feed, for GHRSST this might be:
- % of pixels with a given confidence value
- Min, mean & max SST value
- Min, mean & max wind speed, solar irradiance, etc
- Get imaginative - add event information, such as hurricanes, algae blooms, upwelling, etc.

## Become a Datacaster

- Definition of initial Datacasting feed specification is complete.
- Datacasting server is deployed on the GHRSST GDAC servers with AVHRR and Modis data streams.
- Alpha release of the Datacasting client.
- Currently the server and client are not for general release.  Contact _[Andrew.Bingham@jpl.nasa.gov](mailto:Andrew.Bingham@jpl.nasa.gov)_ to receive copies and begin testing and experimenting.
- Plan to advertise all available feeds on the Datacasting web site.