Difference between revisions of "2010-08-27: Virtual Workshop WCS Implementation"

From Earth Science Information Partners (ESIP)
Line 41: Line 41:
 
* The WCS protocol – how can/should it be extended for air quality
 
* The WCS protocol – how can/should it be extended for air quality
 
* How should we handle different or even multiple parameter requests? (separate arguments? Lists as arguments?)
 
* How should we handle different or even multiple parameter requests? (separate arguments? Lists as arguments?)
 +
<nowiki>**At the WCS URL level, V1.0.0 only allows one variable per request while V1.1.x allows multiple variables.  If a client or portal is provided (e.g., the DataFed browser), the client or portal should be able to handle multiple variables case even in V1.0.0 by sending multiple requests. -- Wenli Yang**</nowiki>
 
* Duration codes?
 
* Duration codes?
 
* Parameter occurrence codes (POC)?
 
* Parameter occurrence codes (POC)?
 
* Time_Sequence: Ours currently is a single date/time -- should it accommodate a time range (performance is a concern)?  What time standard? (UTC?)
 
* Time_Sequence: Ours currently is a single date/time -- should it accommodate a time range (performance is a concern)?  What time standard? (UTC?)
 +
<nowiki>**The GSFC WCS servers support time range and will pack multiple time slices (e.g., daily, monthly) data into one single file, thus increasing the dimensionality of the output, e.g., 2D spatial => 3D spatial and temporal.  There might be, however, a performance issue.  If a client requests a long time period, e.g., an entire year, for a daily product, the server may not be able to fulfill the request.  Chris Lynnes suggested that the server only do one time step, which means that the client shall send multiple requests for multiple times and assemble the after receiving the data. --Wenli Yang</nowiki>
 
* Use of an API key for authentication.
 
* Use of an API key for authentication.
 
* Output (payload) formats
 
* Output (payload) formats
 +
<nowiki>**GSFC servers currently support HDF-EOS and netCDF-CF1, but there are issues for some products in CF1 compatibility. --Wenli Yang**</nowiki>
 +
 
* Field naming
 
* Field naming
  

Revision as of 14:33, August 25, 2010

Main ESIP page >> Main AQ Work Group page >> Interoperability of Air Quality Data Systems | Standards Implementation Virtual Workshops

Telecon/Screenshare Info

1:30pm EDT
Phone: 866-489-0573 (US, Canada, VOIP); 205-354-0149 (international)
Meeting Code: *2279431*

Screenshare details:
Please join my meeting, https://www1.gotomeeting.com/join/954083041


Introduction

Who is this workshop for? Anyone interested in:

  • Making their data more widely accessible
  • Using standard tools and catalogs instead of custom-made
  • Need help adding a standard interface to data

Participants in this workshop may have varied backgrounds on web services (from novice to expert). The varied experience will allow participants to form mentor relationships.

Problem: Data is distributed, in different formats and can't be accessed by common tools within the AQ Community

Solution: Create a standard interface to the data using OGC Web Coverage Service

In-depth Details (programmers?)

Case studies of how Data Systems Implemented WCS:

  • DataFed - Kari Hoijarvi, Rudy Husar
  • DLR
  • Giovanni/NASA - Wenli Yang/Greg Leptoukh
  • RSIG - Todd Plessel
  • Airnow- Steve Ludewig/Tim Dye
  • Univ. of New Mexico - Karl Benedict
  • Unidata - Ben Domenico

How-To

Questions about WCS

What WCS questions/issues have you encountered? If you know the answer to these questions please respond below the question with ** and add your name.


Questions from Steve Ludewig, Sonoma Tech

  • The WCS protocol – how can/should it be extended for air quality
  • How should we handle different or even multiple parameter requests? (separate arguments? Lists as arguments?)

**At the WCS URL level, V1.0.0 only allows one variable per request while V1.1.x allows multiple variables. If a client or portal is provided (e.g., the DataFed browser), the client or portal should be able to handle multiple variables case even in V1.0.0 by sending multiple requests. -- Wenli Yang**

  • Duration codes?
  • Parameter occurrence codes (POC)?
  • Time_Sequence: Ours currently is a single date/time -- should it accommodate a time range (performance is a concern)? What time standard? (UTC?)

**The GSFC WCS servers support time range and will pack multiple time slices (e.g., daily, monthly) data into one single file, thus increasing the dimensionality of the output, e.g., 2D spatial => 3D spatial and temporal. There might be, however, a performance issue. If a client requests a long time period, e.g., an entire year, for a daily product, the server may not be able to fulfill the request. Chris Lynnes suggested that the server only do one time step, which means that the client shall send multiple requests for multiple times and assemble the after receiving the data. --Wenli Yang

  • Use of an API key for authentication.
  • Output (payload) formats

**GSFC servers currently support HDF-EOS and netCDF-CF1, but there are issues for some products in CF1 compatibility. --Wenli Yang**

  • Field naming

Implementation of WCS

Testing Services

Outcome

List your server here if you have a WCS implementation. Test with the Service Checker for GetCapabilites, DescribeCoverage and GetCoverage with the WCS Service Tester

Participants

Next to your name add if you are looking for guidance or have implemented a successful WCS and could provide guidance


Next Workshop

We will continue the discussion on WCS in telecon/webex form in 6 weeks. In hopes that the information gained from this session can be implemented/tested and we can move forward with a set of interoperable web services.