Header Sequence Builder

Description Write to headers for all traces in the record, based on a statistic or otherproperty of the entire record.
Module(s) Image Gather Processing, Gather Attributes
Requirements Volume
Related
Works with Gathers


This process is a record-by-record paneled process; it takes a volume and a set of one or more header operations. These operations write to headers for all traces in the record, based on a statistic or other        property of the entire record.

This process won't allow you to alter the fundamental headers that define a volume (e.g. NS, DT, and DELRT for all volumes).    

Note: The process only takes a gather volume as input.      

Create a header sequence builder process

  1. In the Control Panel, open the Process tab.
  2. At the tab header, click the Add icon and select New Process.
  3. Double-click Header Sequence Builder.
  4. Type a name for the process and click OK.
Create edges

When one or more group-by headers are provided, the header operations are applied per group, where a group consists of traces sharing the same value for all group-by headers in a record. Without group-by headers the entire record is a single group.  

  1. In the Details Panel, select the input Volume.
  2. Under Group By, click the blue "+" icon to add a row.
  3. Click the search box and select the Header.
  4. Select the Method:
    • Start a new group whenever group header values change
    • Group by header values in order encountered in record
    • Group by header values in sorted order
  5. Under Sequence Builder, click the blue "+" icon to add a row.
  6. Click the search box and select the Header.
  7. Select the Operations available for the selected target header.
    • Number Sequentially: numbers each trace in a record or group, starting from 1.
    • Number Group: groups in a record are numbered sequentially, starting from 1, with the value for every trace in a group being set to the group number.
    • Count: the value for every trace in a group is set to the number of traces in that group.
    • Aggregate (Max, Mean, Median, Min, Mode, Range, RMS, Standard Deviation, Sum, Variance): the value for every trace in a record or group is set to the aggregate of the specified source header, for that record or group.
    • Cumulative Sum: the value for each trace in a record or group is set to the cumulative sum of the specified source header within the record or group.
    • Number Sequentially Per-value: for each unique value of the specified source header in the input record or group, number traces sequentially, starting from 1. For example:
        input header   :  1000, 1000, 1000, 1001, 1002, 1002, 1003, 1000, 1004
        output sequence:     1,    2,    3,    1,    1,    2,    1,    4,    1     

This is equivalent to the Number Sequentially operation, grouped by the input header and selecting Group by header values in order encountered in record

Note: When a trace is either dropped or its header is empty, it's ignored by all the above sequence functions, and its index/value is not used for any statistic calculations.