CDDIS Bulletin - December 1989
Volume 5 No. 2

In this issue:

• Cover:
  • VLBI Sites Observing After Loma Prieta Earthquake
• Articles:
  • Changes to TELEMAIL Addressing
  • Canadian Space Geodesy Forum
• Data Bits and Bytes:
  • SLR Data Corrections
  • Test Set of SLR Normal Points

On the cover: VLBI Sites Observing After Loma Prieta Earthquake

Changes to TELEMAIL Addressing

On November 18th, 1989 the TELEMAIL addressing system will change to the X.400 environment. This article provides information on this new addressing scheme. Table 2 on the following page 1 and 2 lists examples of the new addresses for those systems that will be functional on November 18. In the examples listed in this table, uppercase is used to indicate entries that must be made exactly as they appear; lowercase is used for entries that will vary depending on the user to be addressed.

The new addressing system uses the same information from the old interconnect method, but the information can be specified in any order and with more options to make addressing easier. The new format is more free-form with the content being more important than the structure:

	TO:  ([keyword]:[value], [keyword]:[value], [keyword]:[value], ...)

Table 1. TELEMAIL Addressing Information

One of the following keyword combinations must be used in the address: the username, the surname/first name/middle initial combination, or the user code. As an example of this new format, the old interconnect address

TO: [username/organization] system/country
TO: [JSMITH/NASA] NASAMAIL/USA

in the new format becomes:

TO: (C: country, ADMD:administrative domain, PRMD: private system, UN: username)
TO: (C: USA, ADMD: TELEMAIL, PRMD: NASAMAIL, O: NASA, UN: JSMITH) or
TO: (C: USA, ADMD: TELEMAIL, PRMD: NASAMAIL, FN: JOHN, SN: SMITH)

Users should note that the Organization component (O: keyword) must be used with the UN: keyword in NASAMAIL and GSFCMAIL addresses; if the FN: and SN: combination is used, O: can be omitted.

GSFCMAIL users can enter the DIR command followed by their username to check what GSFCMAIL information is stored for the entered name:

Command? DIR JRSMITH

*ABC1234 (this value is JRSMITH's user code)
JRSMITH/D999/D900/GSFCMAIL
John R. Smith
(301) 286-6397

Canadian Space Geodesy Forum

The CDDIS recently received the following information from Richard Langley at the Geodetic Research Laboratory of the University of New Brunswick, Canada. It was thought that this communication service may be of interest to the readers of the DIS Bulletin.

As an aid to improving communication among scientists and engineers working with the techniques of space geodesy, an information dissemination and discussion group, called the Canadian Space Geodesy Forum, has been set up on the BITnet/NetNorth/EARN computer communications network. Messages consisting of news, comments, questions, and answers are exchanged among forum participants by means of a LISTSERV list. LISTSERV is an electronic mail utility that allows a message to be sent "simultaneously" to a list of individuals simply by sending the message to the list address. The address of the Canadian Space Geodesy Forum is CANSPACE@UNB.CA. Files can also be distributed or retrieved from CANSPACE including the monthly message archives.

Any topic related to the space geodetic techniques of GPS, Transit, VLBI, SLR, satellite altimetry, etc., may be discussed. Information concerning satellite launches and orbital elements may be posted. Questions are particularly encouraged.

CANSPACE is directly accessible through computers on the BITnet/NetNorth/EARN network. CANSPACE is also accessible from other networks such as ARPAnet, CSnet, UUCP, TELEMAIL, etc. through various gateways. Individuals may also communicate through CompuServe and the various bulletin board systems on the FidoNet network. Although initially intended to link Canadian geodesists and geophysicists together, CANSPACE is open to all.

To subscribe to CANSPACE it is necessary for you to send a message to LISTSERV@UNB.CA (***not*** to CANSPACE) with the following text:

SUB CANSPACE yourname

To find out who else is participating in the forum, send the following message to LISTSERV@UNB.CA:

REV CANSPACE

To get a list of files available on CANSPACE, send the following message to LISTSERV@UNB.CA:

INDEX CANSPACE

To retrieve a file, send the following message to LISTSERV@UNB.CA:

GET filename filetype

Note that "filename filetype" is generally a two-word file name.

To have a message distributed to CANSPACE subscribers, send the message to CANSPACE@UNB.CA. The message will be automatically distributed.

CANSPACE is maintained at the University of New Brunswick by Terry Arsenault. He can be reached directly via SE@UNB.CA or by phone at (506) 453-4698 or by FAX at (506) 453-4943.

If you have any difficulties in accessing CANSPACE or want more information on the use of a LISTSERV message/file server, consult your local LISTSERV resource person or contact the Dept. of Surveying Engineering at UNB.

Richard B. Langley (LANG@UNB.CA)
Geodetic Research Laboratory
Dept. of Surveying Engineering
University of New Brunswick
Fredericton, N.B., Canada
E3B 5A3

DATA BITS AND BYTES

This section is designed to give brief notices of special events or problems encountered in recent months.

SLR Data Corrections

Recently, problems have been noted in several SLR data sets. These data have been corrected, the release flag updated, and will be issued in subsequent monthly issues of the SLR full-rate data sets.

RIGA 100 microsecond error in time correction for data from September, 1987 through May, 1989

KATSIVELY (CRIMEA) 100 microsecond error in time correction for data from September 1987 through May, 1989

ZIMMERWALD range bias of 0.26 nanoseconds or 3.9 centimeters (too long) for data from May 26, 1988 through August 31, 1989

HTLRS data from the system's first occupation of Titi Sima was incorrect by 2 microseconds

In addition, the Bendix Data Services group has been instructed by the Project's SLR Manager to release all HOLLAS data since October, 1988 into the operational data sets. Users are cautioned, however, that there are some possible, unrecoverable problems with this data set. Based on full-rate data analysis, jumps in the satellite ranging residuals as high as 60 to 80 centimeters have been detected. A majority of the passes may not contain any jumps, but some passes may contain one or more jumps of varying magnitudes. The cause of this problem is unknown and therefore, not recoverable.

Test Set of SLR Normal Points

As reported in previous issues of the DIS Bulletin, the Bendix Data Services group has continued the generation of test sets of SLR normal points. To date, the CDDIS now has normal point data produced from the B version of the January through March, 1989 full-rate data as well as those data sets produced from the A version of the April through July, 1989 full-rate data. The entire set of 1988 normal points generated from the latest versions of full-rate data are also available in the CDDIS.