NAME

ccpbin - a module to calculate converted-wave bin numbers. Inline bin numbers are written into the USP trace header CDPBCX. Crossline bin numbers are written into the USP trace header CDPBCY. The traces can then be reordered using standard USP sorting utilities.

SYNOPSIS

ccpbin

Documentation arguments:

[ -? ] [ -verbose ]

I/O arguments:

[ -Ninput_filename ] [ -Ooutput_filename ] [ -rsirs ] [ -reire ] [ -nsins ] [ -neine ]

Earth model arguments:

-zreflector_depth or -treflector_ts_time

-GVs/Vp_ratio or -GpikVs/Vp_ratio_pickfile

[ -vpP_velocity or -VpikP_velocity_pickfile ]

Binning geometry arguments:

[ -xsbin_x_start ] [ -ysbin_y_start ] [ -xebin_x_end ] [ -yebin_y_end ] [ -biinline_bin_size ] [ -bccrossline_bin_size ]

Synthetic data geometry arguments:

[ -synthetic ] [ -gigroup_interval ]

More synthetic data geometry arguments:

[ -sxosrc_x_origin ] [ -syosrc_y_origin ] [ -sxisrc_x_increment ] [ -syisrc_y_increment ] [ -rxorec_x_origin ] [ -ryorec_y_origin ] [ -rxirec_x_increment ] [ -ryirec_y_increment ]

DESCRIPTION

ccpbin calculates common conversion point bin numbers for a reflector at a specified depth or zero-offset converted-wave traveltime. (With converted waves, the reflection/conversion point varies with depth even for a single source receiver pair, so the target reflector must be specified.) All traces read will also be output. Dead traces will be passed through completely unchanged and unprocessed. The bins lie in a regular rectangular grid, although the inline and crossline bin sizes can be different. The calculated CCP bin numbers are written into the USP trace headers CDPBCX and CDPBCY. CDPBCX contains the in-line bin number, and CDPBCY contains the cross-line bin number.

Command line arguments

-?

This option writes out self-doc.

-verbose

This option writes out extremely copious debugging information into the USP log file, and should not be used for a large input dataset.

-N input_file [default: standard input]

-O output_file [default: standard output]

-rsirs -reire -nsins -neine

Standard USP options for specifying starting and ending record and trace numbers, respectively. The default is to process the entire input dataset. (Note: ccpbin uses the USPIO library to read and write traces, and thus enforces consistency in the line header information meticulously. If there are more or fewer traces than the line header specifies there should be, you will get a complaint.)

-zreflector_depth -treflector_ts_time

The reflector of interest can be specified either by depth, or by zero-offset converted-wave traveltime. (So exactly one of these arguments must be provided.) If the depth is specified in terms of time, then a P-wave velocity must also be provided.

-GVs/Vp_ratio -GpikVs/Vp_ratio_pickfile

Exactly one of these two arguments must be provided. For a constant Vs/Vp ratio, use the former. To specify a Vs/Vp ratio pick file, use the latter. Since pick files only support integers, the Vs/Vp ratio in the pick file is assumed to be multiplied by 1000.

-vpP_velocity -VpikP_velocity_pickfile

If the reflector depth is specified in terms of traveltime, exactly one of these must be specified. To specify a constant P-velocity, use the former. To specify a velocity pick file, use the latter.

-xsbin_x_start -ysbin_y_start -xebin_x_end -yebin_y_end

These arguments specify the orientation of the binning coordinate system. The first two arguments give the X and Y coordinates of the origin of the binning; the last two specify the coordinates of the end of the far end, thus determining the ``inline'' binning direction. The first two default to the geophone coordinates of the first live trace. The latter two default to the geophone coordinates of the last live trace. Note that traces outside the range of the specified line will still be binned, although the calculated bin numbers may be negative.

[ -biinline_bin_size ] [ -bccrossline_bin_size ]

These two arguments specify the inline and crossline bin sizes. The default inline bin size is half the separation between the geophone coordinates of the first two live traces (normalized for the number of dead traces in between those). The default crossline bin size is 20 times the inline bin size.

-synthetic -gigroup_interval

By default, the source and geophone locations for each trace are read from the trace header values SrPtXC, SrPtYC, RcPtXC and RcPtYC. If these are not set, probably because the dataset is from a synthetic modeling program, you can instead specify -synthetic and a group interval via -gigroup_interval. The shot and receiver X coordinates will then be calculated using SrcLoc, RecInd, and the group interval. The Y coordinates will all be set to zero.

-sxosrc_x_origin -syosrc_y_origin

-sxisrc_x_increment -syisrc_y_increment

-rxorec_x_origin -ryorec_y_origin

-rxirec_x_increment -ryirec_y_increment

Some synthetic datasets do not even have SrcLoc and RecInd set in the trace headers. In that case, the X and Y start and increment for source and receiver can be set via these real-valued arguments. Common shot gather geometry is assumed, with all receivers for every shot.

BUGS

None known. The program needs to be extended to better support crooked recording lines. Some minor changes should also be made to make the program more efficient. The program requires a large number of command-line arguments to function. Meaningful error messages will be provided if any required ones are missing. Calculated values will be printed out; you may need to know these to later process the data with ccpstk(1).

SEE ALSO

ccpstk(1)

AUTHOR

Joe Dellinger

COPYRIGHT

copyright 2001, Amoco Production Company All Rights Reserved an affiliate of BP America Inc.