What is the GHRC?

GHRC stands for Global Hydrology Resource Center. The GHRC is the data management and user services arm of the Global Hydrology and Climate Center. It encompasses the data and information management, supporting product generation, archival, and distribution of research quality and operational datasets for a variety of data types, including lightning, passive microwave, radar and others.To learn more about the research, data, and tools available to you, please spend some time browsing through our web pages at the Global Hydrology Resource Center at http://ghrc.nsstc.nasa.gov.

Should I cite data obtained from the GHRC?

Yes, please acknowledge that the data came from the GHRC any time you use them in a published paper or public presentation.
Please cite Vaisala's U.S. National Lightning Detection Network data in this manner:

NLDN data provided by the NASA Lightning Imaging Sensor (LIS) instrument team and the LIS data center via the Global Hydrology Resource Center (GHRC) located at the Global Hydrology and Climate Center (GHCC), Huntsville, Alabama through a license agreement with the Vaisala Group. The data available from the GHRC are restricted to LIS science team collaborators and to NASA EOS and TRMM investigators.

Please cite all other GHRC data in this manner:

Data provided by the Global Hydrology Resource Center (GHRC) at the Global Hydrology and Climate Center, Huntsville, Alabama.

For more information see Citing GHRC Data.

Is any of the dataset documentation available online?

Yes. To access the dataset documentation, use HyDRO. Click on a folder to reveal the datasets. Each dataset may have a Guide document, a home page, a dataset catalog entry, a README, and/or one or more browse images.

Is there a listing of the data available from the GHRC?

Yes. The GHRC Data Catalog provides a brief description of each dataset held by the GHRC. There are links in the descriptions to the READMEs for each data set. This is a dynamic page and is updated as the data holdings change

How can I order data from the GHRC?

With HyDRO, you can search through our dataset holdings using multiple criteria to find the datasets that suit your needs. Or, you can browse through our entire dataset list and find out all sorts of information about the datasets. When you find something you like, you may be able to download the dataset directly to your workstation, or you can submit an order to GHRC User Services to have the dataset stagged for your FTP pickup. HyDRO is fast, and easy to use. Give it a try!

Is there a charge for the GHRC data?

No, currently the entire GHRC data holdings are provided without charge.

How are the data distributed?

The GHRC promotes distribution of data electronically. Custom orders are distributed via anonymous FTP. Many datasets are available realtime via electronic download from our Data Pool. However, at times the GHRC may choose to custom distribute data on other media types.

How do I FTP data from the GHRC?

Much of our data is already online and can be retrieved via HyDRO, or the GHRC Data Pool. Other datasets are stored in "near-line" (archive) storage and must be staged for FTP pickup. To request data that is not online, place an order for data via HyDRO. Once the order is processed, you will receive an e-mail message containing the FTP instructions for picking up the ordered data.

Example e-mail message:

The order you placed with the GHRC is now ready. You may access the data via anonymous FTP using the following instructions:

ftp microwave.nsstc.nasa.gov
for user name, enter: anonymous
for password, enter: your email address
change to binary: binary

This data will remain in this directory for FIVE days. After that time, it will be removed.

Can I access any data sets directly?

Yes, the GHRC has many data sets available via web browser, and anonymous FTP. The online datasets can be accessed via HyDRO and the GHRC Data Pool. You can also access browse images and accompanying documentation via these portals.

What is the GHRC Data Pool?

The GHRC Data Pool is a half a terabyte of anonymous FTP area where the most current two years of passive microwave data; AMSU-A, SSM/I, and TMI are made available. The Data Pool features Interactive search, subsetting, ftp access and OPeNDAP functionality.

What is a granule?

A granule is the smallest aggregation of data that is independently managed (i.e., described, inventoried, retrievable).

What is HDF?

Hierarchical Data Format (HDF) was developed at the National Center for Supercomputing Applications (NCSA). Most of the data sets in the GHRC inventory are in this format.

What is HDF-EOS?

HDF-EOS is an API that defines several important conventions for EOS mission data. These include the placement of metadata in the HDF file, and the definition of compound data objects to represent satellite remote sensing SWATHs and standard projection GRIDs. Learn more about HDF-EOS here.

Why are the US Composite Lightning Products restricted?

The US Composite Lightning Products are limited to Earth Observing System (EOS) affiliated investigators due to contractual restrictions set by the data producer.

What is the EOS Data Gateway (EDG)?

The EOS Data Gateway (EDG) is the primary interface to all data available in NASA's Earth Observation System Data Information System, and related data centers. This system allows users to search for and order data from several data centers in a single session. The goals of the EOS Data Gateway system are to facilitate Earth science research through improved access to data. The Data Gateway provides a consistent view of data sets held at EOSDIS data centers, allowing users without specific prior knowledge of the data to search science data holdings, retrieve high level descriptions of data sets and detailed descriptions of the data inventory, view browse images, and place orders for data. By logging onto the EOS Data Gateway a user can view the data inventory as well as data set guides, and place an order.

Is there any documentation which describes how to use the EOS Data Gateway?

Yes. An Ordering Tutorial for the EOS Data Gateway (EDG) is available from The Land Processes Distributed Active Archive Center.

How do I log onto the EOS Data Gateway (EDG)?

You can directly access the EDG on the Web using the URL http://ghrc.msfc.nasa.gov:3333. If you need help with this system, you can contact the GHRC User Services office which will provide further instructions. The e-mail address for the GHRC User Services office is ghrc@eos.nasa.gov

Can I order data from multiple Data Centers during one EOS Data Gateway session?

Yes, each data set you have marked for order will be processed by the Data Center responsible for archiving that data. You will receive a message from each individual Data Center acknowledging your order. HyDRO, however, only handles data available from the GHRC.

Can I subset data sets by parameter while logged onto the EDG?

Yes! The EDG has added new subsetting features to the ordering process.

While logged onto the EDG, can I view the data?

If browse data is available for a data set, this browse product can be viewed from the data granule list page. However, browse products are not universally available. The user does have the ability to restrict a search to only return information about data sets for which browse products are available. Additionally, the spatial and temporal coverage of a data set is always available.

How can I get answers for other EDG questions?

Most questions are have previously been asked, and the answers can be found at the EOS Data Gateway FAQ web site.

Why am I having problems using FTP from my Web Browser?

Most anonymous FTP sites today require 'Passive Mode' capability. If you are using Internet Explorer, please check the options under: Tools > Internet Options > Advanced tab. Verify that:
"Enable Folder View for FTP sites" is not checked.
"Passive FTP" is checked.

This will allow you to download files one at a time. Currently there is not an option for a multiple file transfer.

If you are using Netscape, Mozilla, or another type of browser, you may need to consult your Browser documentation or contact your system administrator for assistance.

Why am I having problems downloading data from your FTP site?

In order to better assist you with your FTP problems, please answer the following questions:

1) Have you connected to this FTP site before? Were you able to download the data successfully?
2) Are you using an FTP client or a DOS/UNIX command window?
3) What error messages have you encountered? For instance, “Connection Refused” or “Connection Timed out” messages?
4) Is your computer secured behind a firewall? If so, what type?
5) Please provide the IP address/domain name of your computer.
6) Try using "Trace Route" and "NS Lookup" to help pinpoint the problem.

type “tracert xxx.xxx.xxx.xxx” within a DOS/command window
type “traceroute xxx.xxx.xxx.xxx” if using a UNIX-based system.
(The xxx.xxx.xxx.xxx represents the FTPHOST name from the E-mail Notification.)

If you experience problems with the above test, please contact your system administrator for assistance. Please include all output from above questions/test in all correspondence with the GHRC User Services office, ghrc@eos.nasa.gov.

Where can I get FTP software that supports passive mode?

There are many sources for FTP software, and none are specifically endorsed by the GHRC.

The SGI UNIX Operating System 6.5.14 will support Passive Mode if you use 'ftp -p' from the command line.

A wide variety of FTP software packages with passive mode support can be found here.

Information concerning Passive Mode may be found at the following URL:
http://www.slacksite.com/other/ftp.html.

If additional FTP support is needed, you may need to contact your system administrator for assistance.

NASA Information Contact: Michael Goodman, Global Hydrology and Climate Center GHRC Web Curator: GHRC Web Team Last update: Wednesday, 18-May-2005 00:07:04 CDT If you have trouble viewing or navigating this page, please contact GHRC User Services. U.S. Government Compliance report.