OPEN FILE
REPORT 99-449
OPEN FILE
REPORT 99-449
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SEG-Y Formatted Files
Seismic Reflection Data from the Gyre 1997 Cruise
Raw Lines
This directory contains the raw, unprocessed data
and seg-y headers collected on this cruise. The files are named
in the following format. l1f1.sgy where l stands for line
followed by the line number and f stands for file with a number
indicating which segment of the line is contained with in the file.
In this example l1f1.sgy would stand for line 1 file 1
Processed Lines
These files contain
the processed seismic data for the cruise. The data were
processed in Promax7.2 on a SGI Indy machine running OS IRIX 6.5.
Files were named in the following manner: line1pro.sgy where
line number is followed by "pro" to indicate processed lines.
Processing was only performed on the longest subset of each line.
The following is a list of the flows performed on the raw seg-y data.
Flow 1 : load file and geometry
2D Marine geometry spreadsheet
Seg-Y Input
File
to input
Raw.seg-y
Store Processing History
Yes
Input Auxiliary Traces
Yes
Get
Channel Number from Trace Headers
Yes
Input Trace Format
Get from Headers
Display ensemble Formation
No
Data
Input Sample Rate
0.5 msec
Maximum Time to input
variable
Is
this Stacked Data
No
Max
Traces Per Ensemble
120
Primary Sort Header Word
SHOT
Input Primary Selection Choice
Input all
Input secondary selection Choice
None
Input global XY coordinates
No
Use
coordinate Scalar
Yes
Remap Seg-Y header Values
No
Inline Geometry header Load
water velocity
1525
Primary header to match database
FFID
Secondary Header to match database
None
Match by Valid trace Number
NO
Drop
traces with Null CDP headers
No
Drop
Traces with Null receiver Headers
No
Verbose Diagnostics
YES
Trace header Math
select
Mode
fixed equation Mode
define header equation
FFID =CDP
Disk Data Output
output
dataset file Name
geom
New
or existing file
New
record length to output
0 (default parameter means include all)
Trace sample format
16 bit
Skip
primary disk storage
No
Flow 2: Mute and Deconvolution
Disk Data Input
Read
data from other lines/surveys
No
Select input file
geom
Trace read option
Get all
Read data multiple times
No
Input trace headers only
No
Override input datas sample interval
No
Trace Muting
Reapply Previous mutes
no
Mute time reference
Time 0
Type of Mute
TOP
Starting ramp
30
Extrapolate mute times
No
Get Mute Times from Database
Yes
Select Database
Topmute (Horizon picked ~300
ms above were bottom)
True Amplitude recovery
Apply spherical divergence corrections
NO
Apply inelastic attenuation correction
NO
Apply db/sec corrections
YES
DB per second constant
6
Apply time raise to a power corrections
NO
Time power constant
NO
Apply effect to data or remove function
APPLY
Maximum application Time
3500-4000
Spiking Predictive decon
Type of deconvolution
MIN PHASE SPIKING
Decon Operator length
80
Operator white noise level
.1
window rejection length
2
Time gate reference
DATABASE FILE
Select decon gate from Database
Select database
DECON
Output traces or filters
TRACES
Apply a band pass filter after decon
NO
Reapply mutes after decon
YES
Disk Data Output
Output
dataset file Name
decon
New
or existing file
New
record length to output
0 (default parameter means include all)
Trace sample format
16 bit
Skip
primary disk storage
No
Flow 3 Stack
Disk Data Input
Read
data from other lines/surveys
No
Select input file
decon
Trace read option
sort
Primary Sort header word
CDP
Secondary sort header word
NONE
Sort order dataset
*/
Presort in memory or disk
Memory
Read
data multiple times
No
Input trace headers only
No
Override
input datas sample interval
No
CDP Ensemble Stack
sort order of input ensembles
CDP
Method of trace summing
Mean
root Power scalar for stack normalization
0.5
Apply final datum statics after Stack
Yes
Has
NMO been applied
No
Disk Data Output
Output
dataset file Name
stack
New
or existing file
New
record length to output
0 (default parameter means include all)
Trace sample format
16 bit
Skip
primary disk storage
No
Disk Data Input
Read
data from other lines/surveys
No
Select input file
stack
Trace read option
get all
Read
data multiple times
No
Input trace headers only
No
Override
input data's sample interval
No
Bandpass Filter
Type of Filter
single filter
Type of filter specification
ormsby bandpass
Phase of filter
Zero
domain of filter application
Frequency
Percent zero padding
for FFT
25
Apply notch filter
no
Ormbsby bandpass filter
values
4-8-100-150
Reapply trace mute after
filter
yes
Seg-Y Output
type of seg-y
standard
file name
line1pro.sgy
Retrieve history form header
yes
copy reel header
default
job id for binary header
9999
line number for binary header
9999
desired trace format
4 bit integer
maximum time to output
variable
remap seg-y header values
no