Unidata is pleased to announce that it will be maintaining a publicly-accessible code repository for the jj2000 software library. jj2000 is a JPEG 2000 encoder/decoder written in pure Java; it is used in the THREDDS Data Server (TDS) and the NetCDF-Java library to support JPEG 2000 compression in GRIB2 files.

JPEG 2000 is an image coding system that uses compression techniques based on wavelet technology. Unlike the older JPEG standard, JPEG 2000 can perform either lossless or lossy compression of data.

Editor's note: Shawn Cheeks was a Unidata Summer Intern in 2013 and again in 2014. He is a senior at Marshall University in Huntington, WV, majoring in computer science and applied math with a minor in meteorology. He plans to continue on to graduate school to eventually earn a PhD in atmospheric science.

Shawn Cheeks writes:

During my internship last year with Unidata, I developed an Android version of a netCDF Subset Service form. Coming back this year, I wanted to expand my endeavors in mobile development by writing an application that works on all mobile platforms. To do this, I decided to use Apache Cordova because it takes a JavaScript/HTML file and packages it as a native application for any mobile platform. The product of choice this year was Unidata's radar data as it seemed to be a product well suited for mobile users.

Read Shawn's full posting over on the Unidata Developers' Blog.

The NetCDF-Java/Common Data Model (CDM) library and THREDDS Data Server (TDS) version 4.3.22 were released on May 27, 2014. The development team recommends this upgrade for anyone using the CDM or TDS.

On Friday, March 28, 2014 the Unidata Program Center (UPC) updated the demonstration THREDDS Data Server (TDS) running on thredds.ucar.edu to version 4.5 of the TDS software. After encountering some issues with the updated version, including problems with community members' IDV bundles not loading as expected from thredds.ucar.edu, UPC staff reverted the demonstration server to version 4.3 on April 1st.

UPC staff had became aware that TDS version 4.3 running on thredds.ucar.edu was not keeping some dataset indices up to date automatically. This situation required manual intervention by UPC staff to keep the indices updated, which, coupled with changes in UPC security procedures following the intrusion on February 20, 2014, increased the urgency of releasing a new TDS version that fixed the problem. After internal testing convinced us that TDS version 4.5 was functioning properly, we followed the normal procedure of updating UPC servers (specifically thredds.ucar.edu) before releasing the package to other sites. This staged release process normally allows us to find and fix "real world" issues that are not caught by internal testing.

The NetCDF-Java/Common Data Model (CDM) library and THREDDS Data Server (TDS) version 4.3.21 were released on March 12, 2014. The development team recommends this upgrade for anyone using the CDM or TDS.