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FROMSEGD PEP-клиент.
The program is designed for demultiplexed and multiplexed seismic data
convertion from SEG-D format (Rev.0, Rev.1 and Rev.2 with special conditions)
from tape to output SEG-Y file.
The program allows to select field records and channels by
their numbers and types. It's possible to set end time of
output traces.
The program may be used for tape-to-tape convertion without temporal disk file
creation.
It's possible to get listing of tape contents instead of conversion to SEG-Y.
To input SEG-D data to UNIVERS they must be converted to SEG-Y file on
disk and this file may be imported by standard procedure.
The program is a PEP-client, this means it run under special packet
executor pktexec, which serves parameters
setup, job control and log viewing.
Parameters setting and running the program is performed from under the
packet execution program pktexec. The
typical session consists of the following steps:
- Launch the program from UNIVERS menu.
- Project setting, the data directory of which contains the initial
modification (menu item File - > Project...).
- Enter input tape device.
- Enter needed field records.
- Enter needed channels.
- Select mode of the program operating.
- Enter output SEG-Y file location.
- Run the program (button Start in the toolbar or menu item
FROMSEGD -> Start).
- The user can monitor a course of operation of the program in the runtime
panel.
- After successful termination of the program the program should return the
code 0, there should be no error messages in the information strings, and at the
panel of results contains several important characteristics of input tape and
output file.
- To view the the protocol of passing of the program it is necessary to
press the button View log in the toolbar or to select the menu item
FROMSEGD -> View log. Protocol contains information on the generated
headers. The log may contain detailed information about tape contents.
- To exit the program it is necessary to press the button Exit in
the toolbar or to select the menu item File -> Exit.
- Name: Input tape device
Type: filename
- Name of the tape device where source tape with SEG-D data is
mounted. Different operating systems and hardware
configurations obtain different names for tape devices.
Please ask your system administrator about exact name of
tape device on your system.
- Name: Output SEG-Y file
Type: datafile
- Path of the resulting SEG-Y file. The name may point some
disk file to create or name of target tape device to put
resulting traces. The file name may be absent in case of
the program operating mode does not lead to creation of
output SEG-Y file.
- Name: Main operating mode
Type: enum
- The mode of program execution:
- Convert SEG-D to SEG-Y
- perform the convertion, printing
information from SEG-D headers to log;
- Print SEG-D contents
- print information from SEG-D
headers to log but don't produce output SEG-Y file;
- Explore SEG-D contents
- extensive printout of SEG-D
headers and other information from tape to reveal the
SEG-D tape specifics and solve the problems with data
- Name: Select records
Type: string
- List of selected field records for output. It's possible to
select all records, setting all for this parameter. List
of comma separated numbers is allowed too. Each number is a
field record number, but not a sequential number of file on
the tape! Several sequential numbers may be marked via dash
(minus).
Examples of selection:
As a result output SEG-Y will contain field records with
numbers 1,3,5,7,8,9,10,12,13,14 in case of all of them are
exist in source SEG-D tape.
- Name: Select traces (channels)
Type: string
- List of field channels (traces). It's possible to select
channels by their type or number. Next types are
recognized:
- all - all channels in the source tape;
- used - all useful channels that are not marked as Unused;
- data - all channels marked as seismic;
- aux - all useful channels not marked as seismic.
To select channels by their numbers (sequential order from 1
in field record) t's possible to list them with comma
separator or with dash (minus) for ranges of numbers.
Only one type or list of numbers must be set.
Example of channels selection:
Resulting SEG-Y will contain traces with numbers 2,5,6,10,11,12,13.
- Name: Force end time of trace, ms (0 - autodetect)
Type: float
- Zero in this field means autodetection of end time of output
traces. In special cases it's possible to set exact end
time which overrides autodetection procedure result.
Resulting traces in this case will be stripped or filled by
zeros at the end to comply the setting.
- Name: Maximum tape block size, bytes
Type: int
- Maximum size of the input tape block in bytes. Usually it's
equal to 64 kilobytes (65536) but in case of special tape
device and OS driver with limit may be greater. Please set
maximum allowed tape block for source tape device. System
adiministrator may help here. This allows to read correctly
tapes will very long blocks.
- Name: Stage of data processing
Type: string
- Current state of program execution.
- Name: Current tape file / record number
Type: int2
- Two numbers which identify the tape file currently
processed. The first is sequential number of tape file.
The second is field record number.
- Name: Traces in current record (used / unused)
Type: int2
- Two numbers which describes number of useful and not useful
traces in the current field record.
- Name: End time of trace, ms (actual / expected)
Type: float2
- End time of traces in current field record. The first
number coinsides to actual number of samples and the second
just the value from SEG-D header.
- Name: Total number of field records on the tape
Type: int
- Number of field records on the source tape.
- Name: Output SEG-Y file
Type: datafile
- Path to the output SEG-Y file or tape device.
- Name: Number of traces in output file
Type: int
- Depends on number of field records, channels and custom
selection rules in input parameters.
- Name: Number of output field records
Type: int
- Number of selected output field records in resulting SEG-Y
file.
- Name: Number of channels in output file
Type: int
- Number of channels (traces of the record) in output file.
- Name: End time of the trace in output file, ms
Type: float
- Effective end time of output traces. It is automatically
detected or set by user explicitly.
- Name: Sampling rate of the trace in output file, ms
Type: float
- Detected automatically from SEG-D headers.
For detailed acquaintance with the user interface of the shell of the
packet execution program, see the description of the program pktexec. An example of the window of the
shell with active panel for input of parameters is shown below:
The program recognizes and converts to SEG-Y seismic data in formats SEG-D
Rev.0 and Rev.1. Information about observation system geometry, alias
filtring and other miscellaneous data is used by the program and is not
translated to SEG-Y.
The program may be used for reading SEG-D Rev.2 data too,
but the tape must have structure of files and blocks
compatible with SEG-D Rev.0 and Rev.1 rules.
All formats described in SEG-D Rev.1 are supported: 0015,
0022, 0042, 0024, 0044, 0036, 0038, 0048, 0058, 8015, 8022,
8042, 8024, 8044, 8036, 8038, 8048, 8058.
On the output of the program is SEG-Y file located on disk or tape.
Format of SEG-Y comply to Rev.0 published in Society of Exploration
Geophysicists, digital tape standards Geophysics, v.32, p.1073-1084; v.37,
p.36-44; v.40, p.344-352. Output samples in SEG-Y are always in REAL*4
IBM S/360 in any cases.
Supported platforms:
- The workstations of the family SUN SPARCstation with operating system
Solaris 8.
- The workstations with x86 architecture and OS Linux.
The program gets the name of the operative project through the variable of
environment PROJECT. If the program is started from under the shell, this
condition is fulfilled by selection of the operative project.
The program determines the location of the system files of the package
from a variable VSPHOME, defined in the user`s profile or in the file
setup file. This file should contain paths to the directories of data,
jobs and protocols of execution of the projects and also paths to the system
files of the VSP package.
The program searches for the definition of parameters in the files
$VSPHOME/etc/FROMSEGD.pep and $VSPHOME/etc/vsp.pep
The user`s home directory should contain a setup file. This file
should contain paths to the directories of data, jobs and protocols of execution
of the projects and also paths to the system files of the UNIVERS package.
The program loads the default values of parameters from special files in
the following order:
- $VSPHOME/app-defaults/FROMSEGD.parameters.def - general-system directory of
the default values of parameters.
- JOBS/$PROJECT/FROMSEGD.parameters.def - directory of the jobs of the
current project.
- $HOME/.vsp/FROMSEGD.parameters.def - directory of user's settings.
Thus, the user's settings have a priority above the general-system and the
project settings.
The program needs tape device for reading SEG-D data since SEG-D Rev.0 and
Rev.1 strictly depends on file and block structure which is represented only
on tape device and is not supported by UNIX disk files.
Other requirements are defined by the shell of the packet execution
program pktexec.
All messages are moved to the standard stream of errors. If the program is
started from under the interactive shell, the messages are saved to the file
of the protocol of the transmission of the job LOG/$PROJECT/FROMSEGD-#.log. The
messages of classes FATAL and ERROR are placed in the area of messages of the
interactive shell after the program termination.
The program creates the detailed protocol of input tape structure. SEG-D
Rev.2 extensions are not supported.
Example of program log:
INFO: Job number is 64.
INFO: Developer's level of the session is 1.
INFO: Start of FROMSEGD application.
INFO: Version: 1.
INFO: Project: TEST2
INFO: Moment: 2004/02/10 17:38:27
INFO: Target media is disk file /net/data4/DATA/TEST2/from_segd.sgy
INFO: ***********************
INFO: *** Record # 000006 ***
INFO: ***********************
INFO:
INFO: ### SEG-D Rev. 0.0
INFO: ### General Header:
INFO: Field record number: 6
INFO: Format: 0015 - 20 bits, binary multiplexed
INFO: Record type: 8 - <unknown value>
INFO: Record length: 30720 ms (15360 samples)
INFO: Base scan interval: 2 ms
INFO: Recording date (YY/MM/DD HH:MM:SS): 1999/02/2 10:56:26
INFO: Manufacturer code: 15
INFO: literally Halliburton Energy Services; formerly, Texas Instruments, Inc.
INFO: Manufacturer format: 0
INFO: >>> Trace 1: Up hole
INFO: Channel recording period: 0 .. 6144 ms
INFO: Scan type 1, Channel set 1
INFO: Gain control: 9 (IFP gain control)
INFO: Descale multiplier: 0.0175781
INFO: >>> Trace 2: External data
INFO: Channel recording period: 0 .. 6144 ms
INFO: Scan type 1, Channel set 2
INFO: Gain control: 9 (IFP gain control)
INFO: Descale multiplier: 0.0253906
INFO: >>> Trace 3: Time break
INFO: Channel recording period: 0 .. 6144 ms
INFO: Scan type 1, Channel set 3
INFO: Gain control: 9 (IFP gain control)
INFO: Descale multiplier: 0.0253906
INFO: >>> Trace 4: Other
INFO: Channel recording period: 0 .. 6144 ms
INFO: Scan type 1, Channel set 4
INFO: Gain control: 9 (IFP gain control)
INFO: Descale multiplier: 0.0253906
INFO: >>> Trace 5: Seis
INFO: Channel recording period: 0 .. 6144 ms
INFO: Scan type 1, Channel set 5
INFO: Gain control: 9 (IFP gain control)
INFO: Descale multiplier: -0.015625
INFO: >>> Trace 6: Unused
INFO: Channel recording period: 0 .. 6144 ms
INFO: Scan type 1, Channel set 6
INFO: Gain control: 9 (IFP gain control)
INFO: Descale multiplier: -0.015625
INFO:
