Review comment 13
Review of netCDF version 3 implementation and operational suitability
NASA's Earth Science Data Systems Standards Process Group (SPG) is considering the network Common Data Form version 3 (netCDF classic), for adoption as a community standard. You are invited to review this Requests For Comment (RFC) in the context of your implementation experience with this data format specification and its suitability for operational use. Only answer questions applicable to your experience. Please send completed review to: firstname.lastname@example.org.
Implementation Experience questions:
- (Your background) Describe in a sentence or two your overall implementation experience related to the proposed specification. (e.g., specification implementer, tools developer, data provider, scientific analyst, science user, etc.) Have you directly implemented the netCDF classic format specification or modified a netCDF classic library using the specification? Did you use pre-existing software, and if so, what did you use?
NASA's Global Precipitation Mission (GPM) Ground Validation System (GVS) is developing a validation network that matches ground radars from operational agencies (e.g., NOAA's NEXRAD/WSR-88D radars) and satellite observations. Most of the development is done using IDL, and data products are generated using IDL's support for netCDF 3.6.2.
- (Completeness) Does the specification provide all the detail you need to implement it in software? (e.g., to read or write a data file; to implement or modify the library, a profile or extension; or develop a tool such as a format translator) If not, describe what is missing in the specification.
- (Accuracy) Do any parts of the specification contain inaccuracies, or internal inconsistencies? If so, please provide details.
None that we have noticed.
- (Clarity) Is any part of the specification ambiguous, or poorly explained? If so, please provide details.
Not that we have noticed, and again, since we are developing in IDL most of these details are "hidden" from us.
- (Balance) Does the standard describe the right set of concepts and data types, and enable the appropriate data operations for its intended users? Is this set of concepts and data types an overly broad set (requiring excessive complexity) or narrowly simplistic set?
netCDF seems to have a good "balance"
- (Usefulness) How well does this specification meet your information sharing needs? (e.g., does it work well with the data types and data manipulations in your application? Does it properly represent your datasets? What are the pros and cons of this data format?)
netCDF is very commonly used in the atmospheric sciences community.
- (Implementation) What implementation challenges does the proposed standard present? (e.g., does it require advanced processing power, large amounts of memory, complex configuration, etc.? Does it scale to a production environment?)
It is easy to use in development and on the user side too.
- (Flexibility) In what software environment(s) have you used netCDF classic (e.g., Solaris, Linux, Windows, Mac OS X)? Have you implemented, tested or deployed netCDF classic or packages other than those provided by the original netCDF classic and developers?
Development and operations in Linux. Personal use on the Mac OS.
Operational Suitability questions:
- Do you currently use or plan to use netCDF classic in a production setting? What types of applications do you use with netCDF classic? Is netCDF classic applicable to your applications (e.g., Does it work well with the data types and data manipulations in your application?)
Currently in use in prototype, planned for use in operations.
- Why do you choose to use netCDF classic over other data formats for your applications?
Supported by IDL, easily understood data model, lots of read/write tools in use, widely used in the atmospheric sciences community.
- Have you or your users encountered any difficulty when using some of the data access or visualization tools (e.g., IDL, GrADS, etc.) on netCDF classic data files? If you have, please provide a brief description of your experience.
- Does the netCDF file format meet your requirements for storing and accessing data? (e.g., Can it handle the data types in your applications?)
- What operational challenges or limitations does netCDF classic 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)
No operational challenges, it is easy for developers and users.
- What benefits does netCDF classic present? Do the benefits of netCDF classic 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?)
Easy for developers and users.
- How much data do/will you provide or archive in netCDF classic? (number of distinct data products or data sets, total data volume, number of files.)
Four data products, 0.3-1.0 MB per product (uncompressed), approximately 4000 files per year.
- How many users do you have or expect to have for data in netCDF classic, and what is your expected user community?
TBD, products will be used for TRMM data product version 7 validation in spring/summer 2009.
- (User comments) Any additional comments, observations or criticisms of netCDF classic and the RFC can be provided here.