Data Translation Web Service (DTWS)
In a bid to facilitate and promote data exchanges among space scientists, the CDF office has developed a web service called Data Translation Web Service (DTWS) and a client to talk to DTWS via a web browser. The DTWS is a web service based on the Simple Object Access Protocol (SOAP), an XML-based protocol designed for the exchange of information in a distributed computing environment, and it allows users to translate one or more local and/or remote files into other data formats. Below is a list of the data translation modes that are currently supported:- CDF-to-netCDF
- CDF-to-FITS
- CDF-to-ASCII (Text dump of a CDF file)
- CDF-to-CDF Skeleton table
- CDF-to-CDFML (XML representation of CDF)
- CDFML-to-CDF
- netCDF-to-CDF
- netCDF-to-ASCII (Text dump of a netCDF file)
- FITS-to-CDF
- FITS-to-ASCII (Text dump of a FITS file)
- HDF4-to-CDF
- HDF5-to-CDF
- HDF5-to-ASCII (Text dump of a HDF5 file)
DTWS Client
Since it's not a trivial task for most scientists to learn how to invoke the DTWS service by writing a program, the CDF office has developed a web browser client through which end users can specify one or more local and/or remote files, have the specified files translated, and download the translated files. Upon completion of the requested data translation, the users will be presented with a list of the translated files for http download. Double-clicking on the hypertext linked file name will initiate the file download to the user's local machine/disk. The DTWS client can be invoked by going to this URL http://translators.gsfc.nasa.gov from a web browser.When users submit a file translation request, they can either wait for the data translation to complete (default) or provide an email address (optional) if they don't want to wait for the data translation to complete. If an email address is provided, the names of the translated files along with their locations will be sent to the specified email address.
We are trying to make this data translation service as useful as possible and would greatly appreciate for your testing and any feedback. Please send any comments/suggestions/problems to cdfsupport@listserv.gsfc.nasa.gov.
How to Invoke DTWS within an Application
Since DTWS is a SOAP-based web service, it can be invoked by applications written in any of the programming languages that support SOAP binding (e.g. C, C++, Java, Perl, IDL, JavaScript, etc.). The DTWS uses the RPC/encoded WSDL binding style. Please note that the service can't use RPC/literal or Document/literal because it uses an javax.activation.DataHandler object to receive a binary CDF file.If you would like to translate local files (files on your local machine/desktop), you will have to use Java (unless you want to transfer your local files to a remote machine prior to data translation) since it is the only language (as far as we know) that allows sending binary and text files as arguments/parameters. Here is the info about the data translation web service:
- WSDL is at http://translators.gsfc.nasa.gov/pub/dtws/DataTranslationService.wsdl
- The endpoint of the service is http://translators.gsfc.nasa.gov/dt/dtservice
- If you developing a client application in Java, we
have a static stub available for download at
http://translators.gsfc.nasa.gov/pub/dtws/dtServiceStub.jar.
We strongly encourage the use of our static stub (instead of generating your own from a WSDL file) since it contains the correct Java DataHandler object. Note that there are different versions of DataHandler objects available from different sources and some of them might not be compatible with the one used in the DTWS service. - The following sample programs show how the DTWS services can be called
for translating local and remote files:
- http://translators.gsfc.nasa.gov/pub/dtws/SampleDTserviceClient.java (Java)
- http://translators.gsfc.nasa.gov/pub/dtws/SampleDTserviceClient.pro (IDL)
- The online API documentation (javadocs) is at http://cdf.gsfc.nasa.gov/dtws_apis/docs.
Individual Translators Download
Most of the translators described above are available either in binary or
source code. The CDF-to-ASCII tool (cdfexport) is included in the CDF
distribution package, and this tool is available in the <cdf_install_dir>/bin
directory. We use the tools included in the HDF4 and netCDF packages for the
translation of HDF4-to-ASCII (h4dump) and netCDF-to-ASCII (ncdump). These
two tools are not distributed by us and available from the
HDF and netCDF web sites.
Source Code Download
If you would like to have a copy of any of the translators listed below installed on your local machine or desktop, please download the translator(s) of interest and follow the instructions in the README.install or INSTALL file.
- CDF-to-netCDF
- netCDF-to-CDF
- CDF-to-FITS
- FITS-to-CDF
- HDF4-to-CDF
- CDF-to-CDFML : Use the CDF2CDFML tool included in the CDF distribution package
- CDFML-to-CDF : Use the CDFML2CDF tool included in the CDF distribution package
Binary Download
The table listed below will be populated in the near future.
| Linux | Solaris | Mac OS X | Windows | ||
|---|---|---|---|---|---|
| Power PC | Intel Mac | ||||
| CDF-to-netCDF | Download | Download | Download | Download | |
| netCDF-to-CDF | Download | Download | Download | Download | |
| CDF-to-FITS | Download | ||||
| FITS-to-CDF | Download | ||||
| HDF4-to-CDF | Download | ||||
If you have any questions or encounter problems, please send an email to cdfsupport@listserv.gsfc.nasa.gov and we'll respond as soon as possible.
