Review-1

Review of operational suitability of HDF-EOS5:

NASA's Earth Science Data Systems Standards Process Group (SPG) is considering the HDF-EOS5 for adoption as a community standard. This is the second review of HDF-EOS5, this one focusing on its readiness for operational use. The questions below are provided to guide feedback from data systems, application providers, instrument teams and others. You only need to answer questions applicable to you. Please send comments to spg-rfc-008@lists.nasa.gov.

1. Describe in a sentence or two your overall experience related to HDF-EOS5 (e.g., science data provider, science data systems, software tools developer, and science data user, etc).

   I can be considered partly as a science data user, a developer of science data service systems, and a secondary scientific data provider.

2. Do you currently use or plan to use HDF-EOS5 in a production setting? What types of applications do you use with HDF-EOS5? Is HDF-EOS5 applicable to your applications (e.g., Does it work well with the data types and data manipulations in your application?)

   Yes, we do have a plan to migrate to HDF-EOS5. This has not fully completed. Our current production system and data services are mainly based on HDF-EOS2. The HDF-EOS was used internally as the major data models for the flagship WCS (Web Coverage Service) products NWGISS (NASA HDF-EOS Web GIS Software Suite), WCS1020, and WCS1.1. These services are compliant to OGC WCS specifications. The HDF/HDF-EOS is the most supported data models in these systems. We will adopt the HDF-EOS5 to facilitate larger file processing and flexible profiles. As we perceive, HDF-EOS5 will be the choice for us to move forward our WCS services and systems.

3. Why do you choose to use HDF-EOS5 over other data formats for your applications?

   HDF-EOS is readily available to store different earth science data. Its flexible internal structure facilitates the expansion to operate on different datasets. Its internal data structure can be easily mapped to complex earth science data.

4. Have you or your users encountered any difficulty when using some of the data access or visualization tools (e.g., IDL, GrADS, ..) on HDF-EOS5 data files? If you have, please provide a brief description of your experience.

   No report so far. Our WCSs support the users to select their desired format. The may retrieve subsets based on layers/bands, geographic areas, and temporal periods.

5. Does the performance of HDF-EOS5 you have experienced meet your requirements? (e.g., Can it handle the data types in your applications? Does it take a long time to read and write HDF-EOS5 files?)

   HDF-EOS works fine. Earth science data are perfectly served using HDF-EOS.

6. What operational challenges or limitations does HDF-EOS5 present? (e.g., Does it take a long time to learn how to use it? Does it require advanced processing power, large amounts of memory, complex configuration, etc)

   Configuration is a little challenge. Web services are our major software products. It is not so easy to make a web service deployable without manually configuring the destination server. The mixing of C libraries and Java libraries may increase the difficult in debugging programs and memory management.

7. What benefits does HDF-EOS5 present? Do the benefits of HDF-EOS5 outweigh the challenges? (e.g., Does it offer the flexibility you want to package the data types in your applications? Does it facilitate interdisciplinary studies?)

   Benefits: (1) open-source software support, (2) large file support; (4) structural data; (5) full support of earth science data types; and (4) xml support. All these make it a flexible data format to manage earth science data.

8. How much data do/will you provide or archive in HDF-EOS5? (number of distinct data products or data sets, total data volume, number of files.)

   Currently we are serving about 10 terabytes of earth science data. We are expanding to serve large educational community.

9. How many users do you have or expect to have for data in HDF-EOS5, and what is your expected user community?

   The data server in the Center for Spatial Information Science and Systems (CSISS) of the University is currently accessed by over 1800 distinct users each month with distribution of about 0.5 TB data and value-added products to users. Many of the data are handled in HDF-EOS in the server side.