<p>There are no bytes in an IBG. SEGDrev1 is a tape format, and the schematic you are referencing in the standards document is a map of how the data is physically stored on a tape. Tape gaps are actual physical spaces on the tape between blocks of data. An IBG is, quite literally, a gap between blocks of actual data. </p>

<p>If you are reading a tape, you should be able to advance the tape to the next block as needed. If you are working with a SEGD file that has been copied to a hard disk, then gaps are nonexistent and you can pretend they are not there. </p>

CC BY-SA 3.0
2015-03-24T21:47:13.930Z
2015-03-24T21:47:13.930Z
txpaulm
<p>How can one determine the number of bytes in the SEGD Revision1 interblock gap?</p>

<p>The quantity is present on page 5 of the <a href="http://www.google.com/url?sa=t&amp;rct=j&amp;q=&amp;esrc=s&amp;source=web&amp;cd=1&amp;ved=0CB8QFjAA&amp;url=http%3A%2F%2Fwww.seg.org%2Fdocuments%2F10161%2F77915%2Fseg_d_rev1.doc&amp;ei=kBgPVY_rN8vYggT1koLACw&amp;usg=AFQjCNFw_v1mXQI7KvOLBIUTT6jof_GYMA&amp;sig2=XamJ0jul-LnpoXrx1lLV7w&amp;bvm=bv.88528373,d.eXY&amp;cad=rja" rel="nofollow">standards document</a>.</p>

<seismology><data-formats>
How to determine the number of bytes in the SEGD Revision 1 interblock gap
user14717
# How to determine the number of bytes in the SEGD Revision 1 interblock gap

(Asked by: username_0 on 2015-03-22)

How can one determine the number of bytes in the SEGD Revision1 interblock gap?

The quantity is present on page 5 of the [standards document](http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CB8QFjAA&url=http%3A%2F%2Fwww.seg.org%2Fdocuments%2F10161%2F77915%2Fseg_d_rev1.doc&ei=kBgPVY_rN8vYggT1koLACw&usg=AFQjCNFw_v1mXQI7KvOLBIUTT6jof_GYMA&sig2=XamJ0jul-LnpoXrx1lLV7w&bvm=bv.88528373,d.eXY&cad=rja).

**Tags:** seismology, data-formats


---

## 1 answers

### Answer by username_1 on 2015-03-24. Score: 3 | Accepted answer

There are no bytes in an IBG. SEGDrev1 is a tape format, and the schematic you are referencing in the standards document is a map of how the data is physically stored on a tape. Tape gaps are actual physical spaces on the tape between blocks of data. An IBG is, quite literally, a gap between blocks of actual data.

If you are reading a tape, you should be able to advance the tape to the next block as needed. If you are working with a SEGD file that has been copied to a hard disk, then gaps are nonexistent and you can pretend they are not there.


---

