Monday, 14 January 2002: 4:44 PM
An Overview of the Live Access Server
This talk presents a high level overview of version 5 of the Live Access Server (LAS), a configurable Web server suitable for large model data sets. LAS is a data visualizer, subsetter (formatter), and inter-comparison environment. LAS supports the computation of model diagnostic quantities on-the-fly from the state variables stored in the model history files. Often the full dynamics of the model -- all components of diffusion and advection and many fluxes -- are included as on-the-fly variables. This approach greatly eases the data storage requirements. Model diagnostic calculations are performed through the "external function" capability of Ferret (a component of LAS), where fragments of original model code can be linked dynamically into the server. Each different model served may utilize custom diagnostic code consistent with its numerical techniques. LAS supports distributed data collaborations. An individual LAS site can provide access both to locally held and remote data sets. Binary access to remote data sets is provided transparently by the Distributed Ocean Data System (DODS). Users can co-plot and difference (with regridding as required) distributed model outputs. A cluster of cooperating LAS sites may unite as "sisters". Sister sites appear to the user as a single (virtual) site. This talk will demonstrate many aspects of the system. The Live Access server can be reached at "http://www.ferret.noaa.gov/Ferret/LAS/ferret_LAS.html".