sz
These data are intended for use by our scientific colleagues. The pages to access them have been set up to make possible a more secure means of access to our scientific data by users outside of GSFC. Access to most of these pages requires a username and a password.
Assuming you have a valid user id and password for these pages, you can use any interactive web browser to see what data are available and to retrieve specific items of interest. Alternatively, if you know what files you want and wish to set up an automated procedure to retrieve them from this web site, several programs exist that will allow you to do this.
One of these programs is called "wget". To run wget, you must obtain the source code and compile it. Then, to use it, for example, to retrieve a DAO data file of EPV, give the command
For example, to retrieve a DAO data file of EPV, give the command
wget --timestamp -nd http://myusername:mypassword@acd-ext.gsfc.nasa.gov/Data_services/science/asm/data/GG2%255X2/Y1998/M01/EPV_I98010300_GG2%255X2_X_ESTRATF.ASM
and the file EPV_I98010300_GG2%5X2_X_ESTRATF.ASM will automagically appear on your machine. (Note that the "%" signs in the file name had to be entered as "%25" in the URL, since "%" is an escape character in a URL, and "%" is ASCII 37, 25 hexadecimal. Use this same escape mechanism for any other odd characters you might need.) The "--timestamp" option, by the way, forces the downloaded file ot have the same time stamp as the file on the remote end. And the "-nd" (aka "--no-directories") option means that the file is to be downloaded to the current directory on the local end. Wget has many options--read the info pages that come with the program for a full description.
Note: the usernames and passwords you need for accessing these data are not valid account names on our systems, so intruders cannot use them to break in. Nevertheless, these raw and frequently preliminary data are not supposed to be open to the general public, so please keep your usernames and passwords as secret as possible. If you imbed them in your batch scripts, please set the file permissions so that only you can read them.
Back to the Data Services page