WMS and Fimex integration plans

Minutes of meeting between Heiko and Egil, 2009-07-08.

Objective

The OSISAF project requires WMS-visualization and reprojection of the satellite data uploaded to Metamod.

Rough implementation ideas

Metamod up to version 2.2 did only handle metadata. All data-delivery was done in thredds. Since we cannot change the thredds code, and the required functionality doesn't exist in a sufficient manner in thredds (ncWMS has been tested, but cannot contour or vectorize data), Metamod will also start controlling the data and use Diana-WMS (Openlayers, Mapserver, Diana) for visualization and Fimex for reprojections.

The idea behind the visualization and reprojection is to deliver a fast picture / reprojection to the user rather than to provide him with a generic visualization/reprojection tool. Therefore, the data-provider (i.e. the OSISAF project responsible) will add information in addition to the discovery metadata on how to visualize/reproject the data.

Implementation Details

Storage of visualization/projection information

This information will be stored in the .xmd files for a dataset/directory. The schema will be extended to contain the optional nodes

<wmsInfo>...</wmsInfo>

and

<projectionInfo>...</projectionInfo>

The content of these nodes will be defined by Trond Michelsen (dianaWMS) and Heiko Klein (fimex). The content will in addition be stored in the database in tables named ProjectionInfo and WMSInfo, referencing to the dataset.

DONE --- Heiko Klein 2009/07/10 13:57

Administrative-Interface for adding information

The interface for adding these information will be linked on the page for creating/updating directories: Upload Data -> Administration -> Add WMS information | Add Projection information It should be administered by all data-providers.

User-Interface for accessing data as WMS / reprojected

The WMS client and the reprojected netcdf files will be accessible directly form the overview table in the dataset-search. In the same column as the dataset-name for the level2 (file) datasets, links to the WMS representation and the different projections will appear.

Caveat

Currently, all user-authentication/authorization for data-access (i.e. IPY-User) is handled in Tomcat/Thredds and not available to Apache/Metamod. All data delivered through Metamod is therefore unrestricted and the WMS/reprojection service may only be used for unrestricted data. This is no problem for OSISAF.

Fimex Implementation

The php-fimex wrapper will create a fimex command-line and convert the files to a temporary file and deliver this temporary file on the fly. This will increase useability but restrict the fimex wrapper to smaller files with conversion times <~ 1minute.

DianaWMS Implementation

TBD by Trond