From: Ruth Neilan Date: 30 Jun 1999 17:38:42 Subject: [SCIGN-0591] SCIGN Site Logs, ref Msg. # 590 ****************************************************************************** SCIGN Electronic Mail Wed Jun 30 17:38:42 PDT 1999 Message Number 0591 ****************************************************************************** Author: Ruth Neilan Subject: SCIGN Site Logs, ref Msg. # 590 Dear colleagues, This message is in response to SCIGN mail message # 590 message concerning SCIGN site log format changes. It is important to note that variations in the fundamental format of the site logs can have an impact on other processes accessing the GPS data and ancillary information such as the site log. The SCIGN regional array has adopted a log format that differs from the accepted log format used globally by all agencies associated with the IGS. For analysts who use only data and information from SCIGN, this may not cause any obvious problems. However, for users attempting to access SCIGN data and logs and who wish to include these with data and log information from other data centers, this becomes a thorny problem. It can impact the ability of other users to mix SCIGN data with other global or regional data in a consistent or automated fashion. The philosophy that has been adopted and adhered to by the IGS is that the site log is the fundamental source of information on a GPS tracking station. To promote uniformity in the use of GPS the site log format has been standardized with obvious upgrades since at least 1991. It is a convention that literally all GPS users adopt including campaign style GPS observations. There is a discussion that has been initiated to further develop the current site log format and it is expected that a number of changes will be adopted later this year. In general this happens only after agreement is achieved as to additional log content and revised format with a broader based discussion. Then everyone converts to the new site log by a specified time -- many of you may recall that the last major effort like this occurred in 1996. Currently, the IGSCB is attempting to ensure that all site logs are in compliance, both in format and content, so that RINEX generation programs, verification programs and SINEX templates can be easily generated and match a common format, the content of which can be considered robust and reliable. This current exercise is sparked by the recently revised and adopted antenna/receiver naming conventions which must be reflected in all logs, RINEX files and SINEX files by July 4 for IGS processing upgrade. I hope that this clarifies the current situation on the divergent file format. Yehuda Bock, Angelyn Moore and myself have had a few constructive telephone conversations as to how to resolve this situation. The SOPAC groups effort is no doubt well intentioned and while the format may be more machine readable for SCIGN implementation, it is incompatible with practically every other reader in use. I have recommended that the SCIGN logs should certainly match the current accepted log format until a new one is adopted. regards, Ruth ============================================================================ Ruth E. Neilan Telephone: (818)-354-8330 Director, IGS Central Bureau FAX: (818)-393-6686 Jet Propulsion Laboratory E-mail (IGS): igscb@igscb.jpl.nasa.gov MS 238-540 E-mail: ruth.neilan@jpl.nasa.gov 4800 Oak Grove Drive Pasadena, CA 91109 IGS CBIS: http://igscb.jpl.nasa.gov/ Secretary: Carol Lorre / tel:818-354-2077 /email: ============================================================================ [Mailed From: "Ruth E Neilan" ]