The functions performed in the operations panel differ from the edit panel in that the SEGY file, or files, are not affected by the operations. The files are simply displayed in various ways, or data is exported to output files. The original file(s) are untouched.

Functions to display various attributes of SEGY files. Some displays will honour the start and end traces from the edit panel.

Most displays are non-modal, that is they do not have to be closed before returning to the main window.

This function presents the current file in a format of the users choice:

• Wiggle trace variable area (black)


• Variable area only


• Wiggle trace variable density with user defined colours


• Variable density only


• Wiggle trace only

This functions displays a 3D volume with the same display format options as the 2D display. A single inline or crossline can be displayed at a time.

The toolbar buttons at the top of the display window function the same as the 2D display. AGC and gated scaling can be applied to the entire 3D volume or to only the displayed traces

The user can move between inlines or crosslines by means of a slider at the top of the display.

When the 3D display button is pushed a dialog box will pop up informing the user of the byte location and format of the inline and xline numbers in the trace headers. These values must be set correctly for the display to work. If you are not sure click "No" and click on the "Trace Display Parameters" button to set the values.

This dialog is used to set the trace display parameters for 2D and 3D displays. It can be accessed from the main window or the trace display window. Changes made here appear in the trace display when the "Apply" button is pressed.

The display parameters that can be set are:

The user can choose from one of seven default colour bars. These bars are generated automatically and saved to a file in the users home directory called "SegyTool-Variable-Density.colours". If this file is corrupted or deleted SegyTool will automatically recreate it with the seven default colours.
To select a colour bar click on the bar itself or its radio button.Then click "Close" to return to the Display Parameters dialog. Click "Apply" to assign the new colour bar to the existing or subsequent displays.

The user can choose to create new colour bars or edit or delete existing colour bars.

To edit a colour bar select the bar and click "Edit selected". To create a new colour bar click on "Add new". Both selections will pop up the Variable Density colour bar editor.

The qdmap (Quality Display map / Quick and Dirty map) is a very simple mapping routine that displays a stick map of all selected SEGY files as well as grid and culture and polygon files and seismic lines from survey files.

Boxes at the bottom of the map show the X, Y coordinates, line name and shotpoint number of the nearest point to the mouse.

The colour of seismic lines can be individually set.

The map display is modeless, that is, the main window remains active while the map is visible

The toolbar buttons from left to right are:

• Exit Button: Closes the map.


• Clone Button: Displays a clone of this map with limited functionality. Lines or 3D volumes can be hidden, have their colour or annotation changed independently of the parent map. Useful for comparing different versions of 3Ds.


• Hide / View Button: Makes layers visible or invisible on the map. Each SEGY file is a layer. Each SEGP-1 line and each grid and culture file is also a layer. This option doesn't delete layers.


• Colour Button (not shown above): Pops up a dialog with a list of displayed lines. One or more lines can be selected and be assigned a colour.


• Set line annotation font.


• Set shotpoint annotation font.


• Delete Layers Button: This button will actually delete the layer but not the underlying file.


• Annotation Button: Sets annotation increments and bias for shot annotation. Annotation can be turned off also.


• Survey File Import Button: This will pop up a dialog that allows the user to define an input survey file in SEGP-1 or other format. All or some of the seismic lines contained in the survey file can be posted on the map with each line a separate layer.


• Import Culture File Button: Import a grid or culture layer from an ASCII file in either Landmark Metafile or Photon ASCII format. Each imported file is a layer.


• Draw polygon around live map data. User can set a whitespace buffer and opt to display corner coordinates of polygon


• Draw Polygon Button: A pop-up dialog alows the user to define a polygon layer name and colour. The polygon is drawn using the mouse buttons and keyboard. The left mouse button adds a point, the right mouse button closes the polygon. The escape, delete, or backspace key removes previously entered points. The polygon can be used to export subsets of 2D and 3D data or for generating reports of data falling within the polygon.


• Import Polygon Button: Import a polygon from an ASCII file with X,Y pairs separated by commas with as many points as needed to define the polygon. The polygon does not need to be closed, it will be closed automatically by the program. A pop-up dialog allows the user to name the polygon layer and define its colour.


• Export Polygon Button: Saves a polygon to a comma separated ASCII file. The file can be imported back into QdMap at a later time.


• Save current map display to a file in PDF format


• Zoom Button: Zoom in on any portion of the map. Multiple zooms are possible.


• UnZoom Button: Reset map back to original size.

The pop-up dialog is used to set the byte location and format of the inline, xline. X and Y trace header locations. The colour of the 3D volume can also be set here.

This function only maps the current file. To add a 3D to the map select from the working set and click the 3D map button. There is no limit to the number of 3Ds that can be displayed on a map.

To add 2D data to the same map select a 2D line from the working set and unselect the 3D(s) that are already plotted. Then click on the 2D mapping button. The selected 2D lines will be added to the same map.

The user can select one of three different 3D displays. The default is to show the inlines as above

The second simply draws an outline around the 3D.

The third plots each inline with live and dead bins colour coded.The trace flags must be set in bytes 29-30 of the trace header for this option to be selected. The flags are 1 for a live trace, 2 for a dead trace.

This operation displays the headers of a SEGY file in a separate floating window allowing comparison to the file displayed in the main window.

When this function is invoked the current file is displayed in a separate floating window. The window has a trace slider and buttons to select the various headers and formats as in the main window. When a new file is loaded into the main window the floating window contents are unchanged. This allows for comparing header values between files..

There is no limit to the number of floating windows that can be displayed.

This operation displays the minimum and maximum values and their respective trace numbers from the edit byte in the current format from the start to end trace.

This operation displays the minimum and maximum values from the one or more user defined byte locations in the current format from multiple SEGY files.
Select the byte locations by double-clicking on the location in the main window, or enter the starting byte location in the Edit Byte text field on the main window. Click "Add Byte Loc" to add each byte location to the list. When all byte locations have been selected click "Continue" to bring up the results dialog.

This dialog displays all the selected files and the user defined byte locations. If necessary de-select individual files and / or alter the trace ranges for files before clicking the "Min/Max" button. Once the button has been clicked the minimum and maximum values for each byte location in each file will be determined and listed in the dialog. This operation is multi-threaded and the results will appear in random order. In other words, the first results returned may not be for the first file in the list.

This operation allows the user to search all trace headers for one or two values. Useful for finding an inline / xline pair.

Enter the first search value along with its byte location and format. If desired, click the Secondary Search value checkbox and enter a second value. When searching for two values both values must be present in the header. The search starts at one trace past the current trace.

The Graph operation displays the current edit byte from start to end trace in a 2D graphical format.

The display is modeless and is updated when a new SEGY file is selected.

The edit byte and format can be set on the graph display. The start and end trace can also be changed to zoom in on a smaller area.

There is a thin line to indicate the current trace. The trace can be set with the trace slider or trace box.

This operation displays histograms of the sample values, or graphs of the peak, average, or RMS amplitudes.

The trace range and time windows can be set by the user as well as clip values. The clip value can be entered in E notation as in "10.50E03".

When this function starts it shows a histogram display. To create an alternate display, select the display type desired and click the "Display" button.

The display is modeless and will refresh itself when a new SEGY file is selected in the main window.

The peak, RMS, and average amplitudes for the file are displayed. Clicking on the "Show" button will show the peak amplitude sample in the main SegyTool window.

The amplitude at the mouse pointer is displayed as well as the percentage of samples in the file whose amplitude is less than, or equal to, the amplitude at the pointer.

The samples can be read as either IBM float or IEEE float. this option is useful in determining whether a file has an incorrect format code.

The diagnostic dashboard can display several attributes for a SEGY file on a single display.

The default is to graph the shotpoint range, X, Y, and peak sample amplitude from each trace.

Also displayed are a histogram of the data samples, a wiggle trace display of a subset of data, and the EBCDIC header.

If there is a problem in the shotpoint range, eg. a negative shot increment where the shotpoint numbers have been ascending, or a zero shot increment, a warning dialog will appear.

The "Open in SegyTool " button is used by SegyTracker to transfer the SEGY file into SegyTool. It is not necessary when dhe dashboard is created in SegyTool.

This dialog can take a long time to generate on large files. it is recommended that it be used only for 2D data.

This function scans the shotpoint range in bytes 17-20 to ascertain the normal shotpoint increment for the file.

Any trace to trace shotpoint increments that differ from the norm are listed. Double clicking on an increment in the list will show that trace in the main SegyTool window.

This functions displays the binary header and current trace header in a table view with an explanation of each each byte location according to the Encana / Devon SEGY standard. This standard closely follows the SeisX SEGY standard with some extra fields in the binary header.

The fields are colour coded according to whether they are essential, recommended, or optional.

The trace header view is live and will change as the current trace changes. There is a trace slider at the bottom of the display.

This display is read only, no editing is possible.

Functions to export data from SEGY headers to text files and export SEGY data in various formats and subsets.

This operation will export the XY coordinates from the trace headers to an text file in a variety of formats. Coordinates can be exported from all or some selected files.

All selected SEGY files are listed in a table with a checkbox to select or deselect individual files and a line name that is made up of the file name up to the ".sgy".

The line name can be edited, for SEGP-1 format the maximum is 19 characters. Avoid blanks or special characters. Legal characters are A-Z, 0-9, &, $, -, and _.

Set the format, byte location, and divisor for the shotpoint. These values indicate how the shotpoint is written in the current trace header, not how it will appear in the output file.

If the shotpoint in the headers is scaled by 1000 enter 1000 in the divisor box. Each shotpoint in the headers will be divided by this value before being exported. Only whole shotpoint numbers are exported, traces containing fractional numbers are ignored.

Enter the format, byte locations, and divisor for the XY coordinates. The divisor will be applied to each X and Y coordinate before export. If the XYs in the headers are in decimetres and they are to be exported as meters enter a 10 here.

Note that when exporting to SEGP-1 format all XYs will be multiplied by 10 to convert them to decimetres automatically regardless of the XY divisor entered.

Select a central meridian for the output file. This value is used to create latitude and longitude values from the header X Y coordinates. Note that this is only necessary for SEGP-1 and UKOA format. Select a valid ellipsoid for the UTM to lat-long conversion. Clarke 1866 is used for NAD 27 coordinates, GRS 1980 for NAD 83.

The X and Y coordinates are exported directly from the trace headers so the central meridian, even if it is wrong, will have no affect on the accuracy of the coordinates, only the lats and longs will be incorrect.

Select the output format:

• Standard SEGP-1 with a 20 line header and lats and longs computed from the XYS
• Standard UKOA with lat longs and XYs.
• Space delimited Line shot X Y with one shotpoint per line and blanks between values
• Comma delimited Line,shot,X,Y with one shotpoint per line and commas between values
• Space delimited Line Trace shot X Y with one trace per line and blanks between values

This function exports XY coordinate data in a PI/90 format which is used extensively in Europe.

The Pi / 90 file format features a user defined header section which contains information about the seismic line being exported.

Users can add this information one line at a time by clicking on the "Add " and entering the relevant information on the dialog box.

An easier approach is to import an existing PI/ 90 file and make any necessary edits. Lines in the existing header can be edited, deleted, and moved up or down.

The user sets the byte locations and formats for the shotpoint, XYs, depth if present, and the day and time in the trace headers. The UTM zone and ellipsoid can also be set.

This function exports from all selected files. The line name which will be exported to the text file can be defaulted to the file name, up to the dot, or set by the user.

Multiple header values in any format can be exported to a text file from the current or all selected SEGYs.

The values could be a Linename, shotpoint, elevation, CDP, static shift or XY coordinates. The user has control over the values exported and the order they appear in the output file.

The "Add Field" button brings up a dialog that allows you to add fields (byte locations) to export.

Fields can be removed from the list if you change your mind. The order of the output fields can be changed by using the "Move Up" and "Move Down" buttons.

Fields in the output file can be separated by any character delimiter or white space.

When exporting values from multiple files the line name should be one of the exported fields

Clicking the "Export" button will bring up a file browser to select the output file.

The bin coordinates from a 3D file can be exported to an ASCII file in the same formats as 2D data.

The inline and xline numbers and X Y coordinates must present be in each trace header.

3Ds need not be perfectly rectangular, missing traces are not a problem.

Enter the byte location and formats for the inline and xline numbers. Set the format, byte location, and divisor for the X and Y coordinates in the headers. The divisor should only be used if the XYs in the headers are not scaled the same as desired for the output file..

As in the 2D XY export select a central meridian and ellipsoid if the output format is SEGP-1 or UKOA.

The available export formats are:

• SEGP-1
• UKOOA
• Line-Tr-X-Y
• Landmark Metafile
• Photon ASCII
• ESRI Shapefile
• Devon Trango
• Seisspace XY
• Seisspace inline xline

NOTE: The live 3D outline option creates a polygon that encompasses the first and last live trace for each inline.

If, as in the example above, there are dead traces in the middle of an inline the live outline will not show them. This is not, strictly speaking, a bug but the live outline function may be changed in future to allow for dead trace "notches" such as this

The EBCDIC header for all or some selected files can be exported to an ASCII text file with one output file per SEGY file.

The name of the file defaults to the SEGY file name with the ".sgy" replaced with ".txt".

The output file name can be edited and the files can be saved in a different directory from the input SEGY files.

This function exports the current file to a SEGY format file.

The output file can be an exact copy of the current file, a subset of the file in terms of output traces or record length, or a reformated file with a different sample format or byte order.

The output files can be created in any file system or directory that is visible to the user.

The first parameter to set in the dialog is the trace range to export. The default is all the traces in the input file.

The trace range is entered as a string where an export of a file of 200 traces would be entered as 1-200 or 1-END. ("END" or "end" can be substituted for the last trace in the SEGY file.)
To export only the first half of the file enter 1-100.
To export the file in reverse order enter 200-1 or END-1.
To export every second trace enter 1-199*2.
To export trace 1 ten times enter 1R10.

Complex ranges can be entered such as 1,3,5,7-28*3,30,31,32-40*2. Remember that the string represents the traces to be exported from the input file.

Press the "Range Help" button for examples of export trace ranges

Enter the start and end time to export. The number of samples in the exported binary header will be set accordingly. Note that if appending to an existing file the number of samples exported must match the existing file.

The byte order on export can be changed if desired although this is rarely necessary.

The input sample format defaults to the format indicated by the format code in the binary header. If the code is "1" and the SeisX flag is not set a format of IBM float is assumed. If the SeisX flag is set the format is assumed to be IEEE float. For a code of 3 the format is assumed to be 16 bit integer. The assumed input format can be overridden by the user.

The output sample format defaults to the input format although the output format can be set by the user.

If the export sample format is 16 or 8 bit integer and the input is IBM or IEEE float the user is given the option to scale the samples to the export dynamic range.

As indicated earlier the range of values that can be represented by a 16 bit integer is -32767 to 32767. For 8 bit integer the range is -127 to 127.

If the data to be exported has values that fall outside the export range the data can be scaled up or down to avoid clipping. The exported sample values will appear to be relatively the same although some detail can be lost if the scaling factor is too great.

If preserving original amplitudes is important the export sample format should be left as either IBM or IEEE float.

If exporting samples in IEEE floating point or 8 bit integer format the format code in bytes 25-26 of the binary header is set according to the value in the SegyTool defaults. For IEEE float the code is 6 in Canada and 5 in the U.S. For 8 bit data the code is 5 in Canada and 8 in the U.S.

The polarity of the data can be changed on export with all sample values multiplied by -1.

The data samples can be clipped on export to a user defined value.

The option to not swap bytes 181-222 applies to Aram field data in SEGY format. It should normally not be checked.

Clicking the "Write File" button brings up a file browser for selecting the output file. The file name need not end in .sgy although that is normally the case.

The output file can be a new file or existing one. If the output file exists the user is given the option to overwrite or append to it. If a SEGY file is to be appended onto an existing file the EBCDIC and binary headers from the current file are dropped and the first output trace is appended to the end of the existing file. Note that the data being exported must exactly match the existing file in the following:

This operation can export SEGY files from all selected files in the working set.

This is useful if you have a group of files that need to have a common format change such as record length, byte order, sample format, or polarity. The files are by default saved with the same name as the input file in a different directory. Unless otherwise specified the files will be saved in a new directory created below the current one called "Export".

The trace range for each output file can be changed from the input in the file table at the top of the dialog.

This operation will merge multiple SEGY files into a single file with one EBCDIC and binary header.

Obviously the files to be merged must share a common sample format, record length, and sample interval.

The trace headers will not be changed in this operation. Some renumbering may be necessary after merging.

All selected files in the current working set will be merged. The dialog will show the files to be merged in a list. Individual files can be moved up or down to change the order of the files on output. Files can also be removed from the list.

Clicking the "Merge" button will bring up a file browser to select the ouput file.

On the rare occasion where the number of samples per trace in a SEGY file is variable this function will create a new SEGY file with a constant number of samples per trace
Note that the number of samples for each trace, i.e. the variable number, must be encoded in bytes 115-116 of each trace header. If this value is missing the function cannot work.
Enter the number of samples for the exported file and each input trace will be either truncated or padded to that length.
The output file defaults to the same name as the input so must be either renamed or written to a different directory.

This option will create a SeisX / SeisWare format SEGY file for each selected SEGY file in the working set.

The output files can simply be attached in SeisX bypassing the data loading routine. This option is for 2D lines only, see the 3D tab for SeisX 3D export.

The first dialog box sets up export parameters common to all the selected files. The byte location, format, and divisor of the shotpoints and XYs must be defined.

The shotpoints and XY coordinates must be present for each trace header in all selected files in a consistent location and format. No interpolation is done during the export.

Select the input floating point format, either IBM or IEEE. Normally if the format code is 1 the format is IBM float. This can be overridden in the rare case where data samples are in IEEE floating point. If the input sample data is 16 bit integer the output wil be the same.

Select the SeisX format either 3.xx or 4.0. Version 4.0 should only be used if you have that version of SeisX.

The scale window is the window of data on each file that is scanned for the peak, average, and RMS sample values. These values are written in the header for each trace and the average values for the entire file are encoded in the binary header. The values are used by SeisX to scale the data for on-screen trace displays. The SegyTool trace display operation described earlier uses the same plotting method and can be used to determine this window. With data that has been properly scaled by the processor the default of zero to record length works well.

The clip value is the maximum sample value that will be exported. Sample values greater than the clip value will be set to the clip. this feature is used to get rid of large spikes that can affect the display scales. The default is no clipping.

The process type and version are elements of the output SeisX file name. These values can be overridden for each individual output file in the next dialog.

The SeisX description is a string of 80 characters or less that is written in the EBCDIC header.

The output files, by default, will be created in the same directory as the input files. To export to a different directory click the browse button and select, or create, a different directory.

Click the "OK" button to bring up the SeisX Export Files dialog.

This option will convert a SeisX formatted SEGY file or files back to a CSEG standard SEGY file.

The shopoint numbers that are written in IEEE float in SeisX are converted to 32 bit integer and scaled by 1000. The XYs are also changed to 32 bit integer.

The sample values, if IEEE float, are converted to IBM float.

All the SeisX specific header information such as the peak, average, and RMS ampltitude values are cleared.

The result is a standard SEGY file that can be imported into any software package that cannot import SeisX formatted files.

The dialog box lists all selected files from the working set. Obviously all files should be SeisX format, if not, a warning message appears and the file is ignored.

The output file name defaults to the input name minus the process and version. The output name can be changed by the user. The exported files can be written to a different directory by clicking on the "Browse" button.

This operation will export a SEGY file for each selected input file. The output file is identical to the input except for diagonal blank stripes through the data (see below). This allows potential buyers to inspect the data for quality purposes but makes interpretation very difficult if not impossible.

The default is to name the output file the same as the input and save the output files in a directory called Striped which will be created under the current directory. The user can opt to rename each output file, or to save the output in some other directory.

The length of the blank stripe and the trace to trace step can be set by the user. The default is a 300 ms. stripe which steps down 30 ms. for every trace.

Use this function to export a range of data samples to a text file. Samples for one or more SEGY files can be exported to a single text file. Users can define the trace range and time range to export for each SEGY.

Users can also select the fields to be exported along with the data samples such as shotpoint, CDP, and XY coordinates. The formats and byte location for each field can be defined. These values must be the same for all selected SEGY files.

The time of each sample is an optional field. This value is calculated by dividing the sample number by the sample rate. The sample rate is read from the SEGY binary header and divided by a scalar which defaults to 1000, the normal sample rate scalar.

The number of decimal places for the sample values and the sample increment can also be set.

The resulting text file can be character delimited, default is a comma, or in columnar format.

Click the "Export" to export the data samples.

This function creates a scaled wiggle trace display with an optional title block and saves it to a standard graphics format. The file can then be viewed using standard graphics software or hard-copy plotted.

The user is given the option to plot the current file or all selected files.

The display parameters are set by the user the same as for the on-screen trace display.
Select gray-scale or black and white display. Gray scale plots the variable area in gray which some users prefer.

Set the annotation parameters on the Annotation tab.

Functions to work with 3D SEGY data data in various formats and subsets. The 3D trace display and 3D map display buttons are duplicated on this tab.

Use this function to create time slices from a 3D SEGY. Slices can be created using all or a subset of the traces in the 3D. The byte locations and formats of the inline and xline numbers must be entered as well as the inline and xline spacing. If these are unknown use the 3D Export Subset dialog to compute the spacings.
Set the annotation increment and the colour scheme desired.
The default scaling method is to scale all samples relative to the maximum amplitude in the time slice range. The maximum value can be scaled to make the time slice display more intense. The default value if 75 percent. A value of 100 percent will use the maximum amplitude unchanged.
Optionally users can enter an amplitude value and all samples will be scaled to that value.
Take care in setting the time range for the time slices. The larger the range the more RAM will be used which could lead to out of memory errors.

Use the "Next", "Previous", "First", and "Last" buttons to navigate through the time slice range. The annotation, scaling type, and colour scheme can be changed without re-reading the sample values.

The display can also be zoomed in for closer inspection.

The time slices can be exported out to a multi-page TIFF or PDF file, one slice to a page. Set the size in inches or centimetres.

This function scans a 3D volume and reports any errors found in the inline, xline, X, and Y values.

The user can set the number of errors to report before terminating the scan. When the scan is finished or terminated the minimum and maximum values are reported for the scanned fields.

Traces containing zero or negative values will be reported. Inline or xline increments other than defined on the dialog will also be reported.

A clean report will look like the following:

This function allows the user to export multiple 3D SEGYs to SeisX format in one operation.

In order for this function to export properly all input files must have the inline, xline, and XY coordinates in the same byte locations and format. The number of traces can vary from one file to another as can the record length, sample rate and data sample format.

At the top of the dialog is a table showing the input file name, the output base file name, the version number, process type, and 3D survey name.

The defaults for the base file names are the input file names up to the first or last dot as selected by the user. The 3D survey name is made up of the input file name up to the first dot.

All of the fields in the table can be changed except for the input filenames. The output file names are made up of "Base file name.Process.Version.sgy". The process name can be changed for all files by pressing the "Reset" button.

Set the byte locations and formats for the inline, xline, X, and Y fields, as well as the XY scalar.

The scale windows default to zero and the record length of the input file unless changed by the user.

The output data sample format can be fixed for all files or allowed to default to the same format as the input file. The SeisX version type can also be set.

Click the "Browse" button to select an export directory for the SeisX SEGY files along with their index files

This function will export a subset of a 3D gather file. The subset is defined by the user entered inline and xline range. Define the byte locations and format for the inlines and xlines which must be present in each trace header. The input sample format and output record length can be changed from the defaults. There are options to change the byte order or the polarity of the output file. There is also an option to only output live traces. Clicking the "Browse" will bring up a file browser. Select a new or existing file to export the subset to and click the "Export" button to export the subset.

This function scans a 3D gather volume and reports any errors found in the inline, xline, X, and Y values.
Optionally a fold display map can be created and saved

Set the byte location and format of the inline, xline, X, and Y values. Set the inline and xline increments. If a fold map is desired the Plot CDP fold map checkbox must be selected before the "Scan" button is pressed.
The user can set the number of errors to report before terminating the scan. When the scan is finished or terminated the minimum and maximum values are reported for the scanned fields.

Traces containing zero or negative values will be reported. Inline or xline increments other than defined on the dialog will also be reported.

A clean report will look like the following:

If the fold map option was selected press the "Plot" button which will bring up the fold map parameter dialog.

Set thee inline / xline annotation start, end, and increments. Choose whether to display grid lines on the map at the selected increment.
Select a colour bar from the pop up dialog and press "Draw". A map display similar to the following will be created.

The annotation and colours can be changed and the map can be zoomed in and out. The map can also be exported to a PDF or TIFF file. As the mouse is moved over the display the inline, xline, X, Y, and fold are tracked.

This function performs single gated amplitude scaling.

The user has control over the method of determining the scalar(s) to apply to the data samples. The scalar can be a user defined constant value, calculated from a percentage of sample values in a histogram, or calculated from the peak, RMS, or average amplitude values within a defined window.

Users can choose to scale only the current file or all selected files.

For each input file the function writes a new SEGY file to a user defined directory with a default name of ScaledSegys.

Set the start and end window times for computing the scalar. Regardless of the window all samples in each trace are scaled.

Select the method for determining the scalar.

This function resamples SEGY data to a coarser or finer sample rate. It is based on " C " code from the Colorado School of Mines.

Resampling is applied to the current or all selected files.

Enter the ouput sample rate and define the export directory. All resampled files will have the original file names.

An anti-aliasing filter is applied before resampling. Resampling is performed by an eight coefficient sinc-interpolation algorithm.

This function applies a Butterworth bandpass filter to the current or all selected files. It is adapted from " C " code from the Colorado School of Mines.

Enter the low cut, low pass, high pass, high cut values and define an output directory.

All frequencies between the low pass and high pass are passed unchanged by the filter. Frequencies greater than the high cut and less than the low cut are attenuated. The filter is tapered between the cut and pass frequencies.

Select the type of start times, sample number or milliseconds. Note that they are start times, not absolute shifts. Set the byte location and format of the start times in the headers.
Set the start and end times of the output traces. The traces will be shifted the difference between the fixed start time and the start times read from the trace headers. The end time will be fixed to the user supplied time.
Set the output directory, the output files will be named identical to the input files so they must be saved to a different directory.

The start times can also be read from a text file in comma separated format or columnar. The values in the file are start times in milliseconds or sample numbers.
As in the trace header shift option the output traces are shifted the difference between the user entered start time and the time read from the text file.
Optionally any missing traces in the text file start times can be interpolated.
Again, the output files are named the same as the input files so a new output directory must be specified.

The output file names will default to the same as the input file which means that either the files must be saved to a different directory than the input or the output files must be renamed either manually by editing the names or by appending to the existing name by clicking the "Append" button which will add the entered string to the end of the file name before the final dot. Click the "Undo Append" button to reset the filenames back to the same as the input files.
Assign the trace range to be muted, which will apply to all selected files. An end trace of zero means all traces in the file(s) are to be muted.
Assign the time range to be muted. The default start time is zero but can be any time within the trace range.
Click the "Browse" button to assign a directory to save the output files to. If the selected directory is the same as where the input files reside the output files must be renamed before applying the mutes.
Click "Apply Mutes" button to apply the mutes to the selected files. Click the "Cancel" button to dismiss the dialog without applying mutes.

This operation is for the very rare occurrence where the number of samples per trace varies throughout a file.

The number of samples per trace and sample rate are written in the binary header. This is where SegyTool and most other programs read these values. The assumption is that the number of samples per trace is constant for all traces so that navigating through a SEGY file is a matter of moving the file pointer a fixed number of bytes per trace. If the number of bytes is not constant then moving from trace to trace is impossible.

This problem can manifest itself in two ways.

In the days of tape storage the number of samples per trace could vary since programs looked for inter-record gaps between traces.
The true number of samples per trace was written in the trace header but this value is not used by most software. A file read from tape this way must have the number of samples per trace fixed before the file can be read properly from disk. At present Segytool cannot deal with this type of error although it will be added to a future release.

The other type of error is where the number of samples per trace written in each trace header is correct but there are more or less samples per trace than is indicated.
This can happen if there are parity errors reading the tape. SegyTool can fix this problem by exporting a SEGY file with a fixed number of samples per trace. the number of samples is the one indicated in the binary header.

As indicated above this problem is thankfully very rare.