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CDDIS Bulletin - December 1990
Volume 6 No. 2
In this issue:
On the cover: Global SLR Site Locations
Many users who access the CDDIS would like to transfer selected
analyzed and ancillary data sets to their home institutions. This
article describes procedures for accessing and transferring these
data from the CDDIS.
Selecting a data set The on-line CDDIS data sets are
stored using the ORACLE data base management system (DBMS). This
facility organizes the data sets into tables with columns and rows.
The CDDIS user interface provides access to these tables through
a series of menus that categorize the data by type (e.g., baselines,
earth rotation, etc.). The user can access the CDDIS data base through
the SQL interface via Main Menu Item 4. Queries to display baseline,
station position, earth rotation, coordinate/eccentricity, as well
as other data sets are listed through a series of sub- menus. The
user then can identify the data set query of interest from the sub-menu.
Each query result is preceded by textual information about the data
to be displayed.
Querying and saving a data set Prior to execution
of a selected query, the user should establish the appropriate output
environment and identify a file on the CDDIS computer to contain
the information displayed from the query. Currently, all queries
are set up to display a terminal "page" (i.e., 24 lines) of data
and pause for user input prior to displaying the next page of information.
Several parameters must be specified to change this display and create
a file to contain the resulting data. If these formatting parameters
are not changed, extraneous text will be saved to the data file with
data of interest. These parameters are discussed below:
- Pause The SET PAUSE OFF command will disable
the feature which controls the scrolling of output to the terminal.
The user will no longer view the prompt text and will not be required
to enter a return from the keyboard to view the next page of the
report.
- Save File The SPOOL fname command will direct the
results of the query to the user-specified file (fname)
on the CDDIS MicroVAX.
- Page Size The command SET PAGESIZE n command specifies
the number of lines from the title to the end of the page. If n is
set to 0, all headings, page breaks, and titles will be suppressed.
- Page Break The command SET NEWPAGE 0 sends a formfeed
or page-eject character between pages of output.
- Headings The SET HEADINGS OFF command will suppress
all headings previously defined in the query.
- Line Size The command SET LINESIZE n will specify
the total number of characters displayed on a line of output before
starting a new line.
The example shown in Figure 1 illustrates a typical session where the
results are saved to a file for printing at a later time; user entries
are shown in bold type. The selected query, BLQSG88,
is a query to the table containing the quarterly baseline solution
for 1988 produced by GSFC from SLR data. This query was chosen from
SQL Query Menu Item 2, Baseline Queries.
SQL*Plus: Version 3.0.6.4.1 - Production on Wed Nov 21 08:16:19 1990
Copyright (c) Oracle Corporation 1979, 1989. All rights reserved.
Connected to: ORACLE RDBMS V6.0.29.1.0 - Production
SQL>
SQL> SET PAUSE OFF
SQL> SET NEWPAGE 0
SQL> SET PAGESIZE 55
SQL> SPOOL BLQSG88.SPL
SQL> @BLQSG88
DOC>
DOC> ***** BLQSG88
DOC>
DOC> Select all columns and entries from the table containing the quarterly
DOC> baseline solutions computed by GSFC from SLR data in 1988
DOC> (BASELINEQTR88_SLRGSFC).
DOC>
DOC> The following are the associated column definitions and units:
DOC>
DOC> Quarter -- Time period of computation
DOC> From Sta. -- From station number
DOC> To Sta. -- To station number
DOC> Baseline/Chord/Geodesic Lengths -- Baseline determinations (meters)
DOC> Baseline/Chord/Geodesic Sigmas -- Sigmas associated with baseline
DOC> determinations (meters)
DOC>#
874 records selected.
SQL> SPOOL OFF
SQL> EXIT
Disconnected from ORACLE RDBMS V6.0.29.1.0 - Production
Figure 1. CDDIS Query Example
Transferring the data set Following successful establishment of
an output environment and execution of the query, the results will be saved to
the file specified in the SPOOL command. The user can copy this file via electronic
networks to his home institution immediately following the completion of the
query's execution. The CDDIS computer is connected to SPAN (DECnet-based), INTERnet
(TCP/IP-based) and BITnet. While accessing SQL for queries, the user can perform
file transfers using any of these networks by entering a $ prior
to the appropriate command. This procedure is illustrated in Figure 2. When passwords
are required for security reasons for these file transfers, they are shown in
this example as pword. Text shown to the right in the figure
and in italics are comments on these file transfer methods. In Figure
2, two examples of each transfer method to the user NOLL at node ROSAT are shown;
the file for this transfer containing data resulting from the executed query
is called BLQSG88.SPL. The first command for each file transfer protocol prompts
the user for the file inputs and network information; the second method specifies
all inputs on a single command line. The first two examples in Figure 2 illustrate
sending a file over SPAN using the VAX COPY command. The next
two examples perform an INTERnet TCP/IP file transfer using the FTP command.
The final two examples show a BITnet transfer using the SEND command;
the qualifiers on SEND are necessary when the recordsize of the file is larger
than the default value of 80 bytes.
CDDIS users are encouraged to try some of these methods for accessing on-line
data. Comments and questions are welcome.
The SLR Analysis Group at GSFC, Code 920, has submitted revised quarterly baseline
and station position data sets for 1986, 1987, and 1988; data from 1979 through
1985 were not replaced. These data can be queried through the DIS by accessing
the SQL menu interface (Main Menu Item 4). The data base tables containing these
data are:
BASELINEQTRyy_SLRGSFC Quarterly baseline solution
POSITIONSQTRyy_SLRGSFC Quarterly station positions solution
where yy refers to the year (79 through 88).
SQL*Plus: Version 3.0.6.4.1 - Production on Wed Nov 28 09:43:28 1990
Copyright (c) Oracle Corporation 1979, 1989. All rights reserved.
Connected to: ORACLE RDBMS V6.0.29.1.0 - Production
SQL> $ DIR/SINCE=TODAY Directory of files created today
Directory MANAGE:[DISCM.ORACLE.SQL.USER]
BLQSG88.SPL;1 635
Total of 1 file, 635 blocks.
SQL> $ COPY Copy file via SPAN
_From: BLQSG88.SPL
_To: ROSAT"NOLL pword"::GSFCMP:[NOLL]BLQSG88.SPL or
SQL> $ COPY BLQSG88.SPL ROSAT"NOLL
pword"::GSFCMP:[NOLL]BLQSG88.SPL
SQL> $ FTP ROSAT Copy file via INTERnet
CDDIS.GSFC.NASA.GOV MultiNet FTP user process 2.2(100)
Connection opened (Assuming 8-bit connections)
LOGIN NOLL
pword
PUT BLQSG88.SPL
to remote file: BLQSG88.SPL
EXIT
or
SQL> $ FTP /USER=NOLL/PASSWORD=pword ROSAT PUT BLQSG88.SPL
BLQSG88.SPL
CDDIS.GSFC.NASA.GOV MultiNet FTP user process 2.2(100)
Connection opened (Assuming 8-bit connections)
$ SEND/FILE/PRINTER/RECORDSIZE=132 Copy file via
BITnet
_File: BLQSG88.SPL
_To: NOLL@ROSAT or
SQL> $ SEND/FILE/PRINTER/RECORDSIZE=132 BLQSG88.SPL
NOLL@ROSAT
SQL> EXIT
Disconnected from ORACLE RDBMS V6.0.29.1.0 - Production
Figure 2. CDDIS Query File Transfer Example
This section is designed to give brief notices of special events, new data
sets, or problems encountered in recent months.
The CDDIS GPS data archive now contains the Fort Davis footprint data set.
These data consists of 56 sessions taken from June 7 through 20, 1990 at eight
sites around the Fort Davis/McDonald, Texas area. The data is available in
raw, binary (Trimble receiver) or RINEX formats.
At a recent CSTG SLR meeting held at GSFC on October 23, 1990, the group
recommended that future SLR data releases contain operational and engineering
data in a single merged data set. Prior to this decision, engineering data
was released to the CDDIS on a monthly basis on a separate release tape. In
the merged form, data classified as engineering can be identified by a release
flag set to Z; operational data has a release flag of A, B, C, etc. When/if
engineering data is considered operational, the release flag will be updated
from Z to the current value for the release flag (e.g., B, C, etc.). This policy
will become effective with data taken during January, 1991.
The CDDIS is now archiving SLR data from the ETALON-I and ETALON-II satellites
in support of the intensive tracking campaign for IERS. The data will be made
available to the general user community on the regular monthly release tapes.
Alternatively, the entire set of data from the ETALON satellites (starting
in February, 1989 and continuing through August, 1990) is available upon request.
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