das2 is the second-generation web-based data delivery, visualization, and analysis system from the The University of Iowa. Data are transmitted to clients along with software to manipulate and display the data.
das2 is the second-generation web-based data delivery, visualization, and analysis system from the The University of Iowa. Data are transmitted to clients along with software to manipulate and display the data.
Das2 consists of several components. Various Java libraries and client-side applications support space science data visualization such as interactive spectrograms, overlays, waveform plots, etc. Distributed data servers and server-side applications here at Iowa and other sites provide self-describing data streams to the client applications. Our IHDEA 2020 video presentation provides a good overview.
Das2 servers conserve network bandwith by providing self-describing streams of data at a resolution matched to the output device.
Das federated catalogs provide a location-independent registry of data sources. Browse the federated catalog of accessible data.
das2java is the Java Swing GUI library used by Autoplot, MIDL and special applications. Das2Core provides client-side data operations such as:
das2C is a portable C-library and utilities which handle much of the server-side data reduction and transformation and provides connectivity for SDDAS.
das2-pyserver is a python replacement for the original perl based server that adds a pre-reduced cache for better performance.
das2py is an efficient python module that loads data directly into NumPy arrays via a C extension. It is based on das2C.
das2pro is a pure IDL das2 client which requires IDL 8.6 and above.
das2dlm is an IDL dynamically loadable module that includes das2C and provides connectivity to SPEDAS. Requires IDL 8.5 and up.
Portable Java Clients provide an interactive plotting experience. As you browse datasets via zoom, pan and slice operations, new values are automatically downloaded at an appropriate resolution from the server.
Autoplot is the most popular das2 client. In addition to its role as a graphical data browser, Autoplot exposes a scripting interface for creating custom interactive displays.
SDDAS (Southwest Data Display and Analysis System) supports das2 data sources and can handle many of the newest stream features.
SPEDAS versions 4.0 and up has support for das2 data sources using das2dlm.
Small demo applications provide custom features for selected data sources.
Our 2017 AGU poster provides a das2 system overview, although it's weighted a bit towards server design.
Our 2018 AGU poster provides an overview of non-java clients, and touches on VESPA integration.
Our 2019 AGU poster provides an overview of data source location resolution using the catalog.
The Das2 2.2 Interface Control Document adds sequence yTags attributes to allow for shorter waveform headers.
MIME types for das2 streams and the top level tag URI can be found on the stream verification page (in process).
View current das2 issues and development on github.com for das2java, das2C, das2py, das2py-server and others.
The first-generation das1 delivers data products via gif images. Data product parameters were set with html forms.
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