RODE - some second thoughts (December 1996)

A dissenting voice has spoken to PDM on the subject of RODE encapsulation of seismic data.

In last months PDM we presented the newly released Record Oriented Data Encapsulation (RODE) format and suggested that, as well as becoming a standard for archival, this may become a standard for field recording of seismic data. An authoritative source in the industry has pointed out that this possibility has been considered by the Field Tape Subcommittee of the Technical Standards Committee of the SEG, they concluded that while they had "spent some time reviewing the RODE format as a possible field tape format [....] the flexibility and wide range of options in RODE have made it impossible [...] to completely evaluate whether it is possible to adopt a version of RODE as a field tape standard. The committee feels that the complete RODE format is too flexible to be suitable for field tape recording without some restrictions. The committee will continue working toward an acceptable subset of RODE for field tape recording." Our source adds a few reasons why RODE may not be a realistic choice for field acquisition at the present time

"RODE (and, in particular, the underlying RP66 V2) format is complex, and may be implemented in many different ways. It is almost impossible to write a program which will correctly read every valid RODE dataset. (For example, the client name field could be 4 gigabytes long)! Therefore most RODE software packages are restricted to reading data that they create, plus any other specific RODE formats for which they have been adapted.

There is no general agreement as to how RODE data should be formatted. For example, should there be one RODE dataset for each shot record, or one per tape volume, or one per line?

SEG-D Rev 2 permits use of fixed block and byte stream devices as an alternative to variable length block devices. Therefore there is no particular need for RODE encapsulation."

So the jury is out on RODE as an acquisition format, any other opinions on this and related matters welcome.

Click here to comment on this article

If your browser does not work with the MailTo button, send mail to pdm@the-data-room.com with PDM_V_2.0_199612_22 as the subject.

© Oil IT Journal - all rights reserved.