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Fix calculation of SEG-Y Index sample rate for Depth volumes

Erik Dahl requested to merge slb-master-EDahl2-FixDepthSampleRateInIndex into slb-master

Type of change

  • Bug Fix
  • Feature

Does this introduce a change in the core logic?

  • [Yes]

Does this introduce a change in the cloud provider implementation, if so which cloud?

  • AWS
  • Azure
  • GCP
  • IBM

Updates description?

Fixes a calculation error for sample rate in the SEG-Y index for DEPTH volumes. (Old version was off by a factor of 1000 ... ) The fix is required because sample rate is specified in different units for Time and Depth volumes:

For Time volumes, first and last sample are specified in milliseconds, and sample rate is in microseconds (millisecond = 1/1000 second, microsecond is 1/1000,000 second)

For Depth volumes, the sample rate is usually (in SEG-Y rev 0 and rev 1) specified in 1/1000 units, e.g. if the Depth of First and last sample is specified in metres, the sample rate (e.g. 4m) will be given a value of 4000. Before the fix, the value would be divided by 1000,000, making the reader think there were 1000 x as many samples per trace as there should have been ....

The fix is to divide Depth sample rate by 1000 rather than 1000,000

Edited by Erik Dahl

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