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Site Identifier Codes

It is anticipated that most sites using the df format will need to define and use their own local conventions for the integer codes used to indicate task IDs, special processing conditions, and data sources. Such local definitions can be managed and prevented from interfering with one another (when importing data sets from another site, for instance) by keying them to a unique site ID.

These site identifiers are long integer codes signifying where a dataset was created. To avoid duplication of codes, all site IDs are currently registered with the central administrative site, Site 1. Sites that are not registered with the main authority may use site ID 0, but their local conventions are virtually guaranteed to conflict with others'. Use of site ID 0, then, is strongly discouraged. (Note that site IDs are needed only by sites which generate datasets; one can certainly read datasets generated by others without having to acquire a site ID first.)

Site 1 is the site where this format originated: the Atmospheric Chemistry and Dynamics Branch (Mail Code 916) at the National Aeronautics and Space Administration's Goddard Space Flight Center, of the the United States Government. Site 1 will be the source of other site registrations and the source of updates and changes to the format. The current mailing address is:

Dr. Paul Newman
Code 916
NASA/GSFC
Greenbelt MD 20711
USA

email to: df@ertel.gsfc.nasa.gov

In addition to its use in separating local conventions, the site identifier code is also used in the audit tree of each dataset, specifying from where each data set referenced in the tree originates

Each code is an unsigned integer at least 28 bits long. The bits are numbered from 0 to 27, starting with the least significant bit. Bits 26 and 27 define an index of site types; the format of the rest of the integer code depends on the site type.


The bit format of the site ID codes is as follows:



\begin{picture}(32,3) \put(0,1){\line(1,0){32}} \put(0,3){\line(1,0){32}} \pu... ... \put(4,0){\makebox(2,1)[r]{26}} \put(6,0){\makebox(26,1)[r]{0}} \end{picture}

typ
(bits 26 and 27, values 0 to 3) type of site
0 : government
1 : university
2 : private industry
3 : other


0 : Government



\begin{picture}(32,3) \put(0,1){\line(1,0){32}} \put(0,3){\line(1,0){32}} \pu... ... \put(19,0){\makebox(5,1)[r]{8}} \put(24,0){\makebox(8,1)[r]{0}} \end{picture}

country
(bits 18 to 25, values 0 to 255) country of site
unit
(bits 13 to 17, values 0 to 31) government agency
location
(bits 8 to 12, values 0 to 31) location of site
group
(bits 0 to 7, values 0 to 255) group within site


1 : Universities



\begin{picture}(32,3) \put(0,1){\line(1,0){32}} \put(0,3){\line(1,0){32}} \pu... ... \put(20,0){\makebox(4,1)[r]{8}} \put(24,0){\makebox(8,1)[r]{0}} \end{picture}

name
(bits 12 to 25, values 0 to 16383) university name
location
(bits 8 to 11, values 0 to 15) campus location
group
(bits 0 to 7, values 0 to 255) group on campus


2 : Private Industry



\begin{picture}(32,3) \put(0,1){\line(1,0){32}} \put(0,3){\line(1,0){32}} \pu... ... \put(20,0){\makebox(4,1)[r]{8}} \put(24,0){\makebox(8,1)[r]{0}} \end{picture}

name
(bits 12 to 25, values 0 to 16383) company name
location
(bits 8 to 11, values 0 to 15) site location
group
(bits 0 to 7, values 0 to 255) group on-site


A few examples follow:

0:
Unknown
1:
U.S. NASA GSFC Chemistry and Dynamics Branch
65536:
U.S. NOAA NMC

next up previous contents
Next: Quantity Codes Up: Centrally Defined Codes Previous: Data Format Codes   Contents
Eric Nash 2003-09-25