Contents

Conventions

The following conventions are used in this document.

Ctrl+S Keys, or key combinations on a PC keyboard.
<SAVE> Keys, or key combinations on the Terraloc built-in keyboard.
File/Save A sequence of selections in the user interface. In this case, first clicking on File in the menu bar, followed by a click on Save.
Quick menu/3 A sequence of selections in the user interface. In this case, pressing <3> (or 3) after accessing the Quick menu.
25, 50, 100, 250, 500, 1000, 2000 Lists available choices in a menu.

Getting Started

What is SeisTW?

SeisTW is a Linux application that is used to control the Terraloc seismic system. It can also be installed on any PC running Linux and used to view and manage seismic records. However, when installed on a PC in this way, all functions accessing the Terraloc API, will be disabled.

Main GUI components


Title bar

At the top of the display you have the title bar. This displays the application name and version. When a record is opened, it will also display the file name of the record.

Menu bar

The menu bar presents the user with the available menu choices. The short-cuts displayed for most menu choices, refers to a standard PC-keyboard (and not the built-in keyboard).

Tool bar

The tool bar presents the user with some iconic views of acqtions trhat can be performed. The tool can be enabled/disabled by pressing <CTR>+<1>, or be selecting View/Toolbar. In normal field work, if only the built-in keyboard is used, disabling the tool bar will free more of the screen area for displaying data.

Record view

The record view shows all traces vertically. On the left side, a time scale is displayed. This time scale adjusts according to sample interval and view options. Tic lines across the view, can be enabled in the View options menu.

At the top of the view, there is a trace marker that can be moved by using the <LEFT> and <RIGHT> arrows. <Shift>+<LEFT> will move the trace marker to the first trace, and <Shift>+<RIGHT> will move the trace marker to the last trace. This marker selects the current trace. In acquisition mode, the top of the view also displays the current Stack On status, and polarity. The Stack On is displayed by squares above each trace. If the square is filled, the stack for that trace is on, and if the square is open, the same stack if off (will not add acquired data). If negative polarity has been selected for a trace, a minus sign is displayed under the square.

To scroll the view use <UP> and <DOWN>. <Shift>+<UP> and <Shift>+<DOWN> will scroll the view one page at a time.

Pressing <+> or <-> will move a time line across the view. Some data for the current trace will be displayed in the status field just below the views. Pressing <.> will set a first arrival marker at the location of the time line on the current trace.

Pressing <CTR>+<8> opens the Velocity analyzer.

Pressing <CTR>+<Space>, openscontext menu with appropriate menu choices.

Press <TAB> to move between views.

Trace view

The trace view displays an enlarged view of the current trace and its frequency content. This view uses the same key functions as the record view. Except, <UP|DOWN> selects the next/previous trace as current trace, and <LEFT|RIGHT> scrolls the view.

In the enlarged trace part of the trace view, pressing <0< will set a reference time marker at the location of the time line. If the time line is moved when the reference time marker is active, the status bar will display, in addition to the normal information, the relative time and the corresponding frequency (i.e. reciprocal time).

In the frequency part of the Trace view, it is possible to check the amplitudes of the frequency components, moving the frequency line by pressing <+> or <->. Please be aware that the values displayed, mostly are interpolated, as the frequency line represents a frequency calculated from the pixel coordinate, which can be in between samples.

Use <CTR>+<Left|Right|Up|Down> to move the borders of the Trace view.

The trace view can be enabled/disabled by pressing <CTR>+<0<> (or by selecting View/Details).

Status bars

There is one status bar containing two fields that refers to the current record, and one status bar containing five fields that refers to the application/instrument.

Record status bar

The record status bar consists of two fields. These fields displays trace centric information.

Field #1
This field shows information recording the current trace.

#nn Trace number.
T Sample interval in microseconds.
D Pre-trig/delay in milliseconds.
Len Length of trace in number of samples.
S Number of stacks.

Field #2
This field shows information regarding the current sample at the location of the time line.

Application status bar

Field #1
This field shows the current record number, i.e. the record nunmber that will be used the next time an acquired record is saved.

Field #2
This field shows the active acquisition mode, i.e. Standard, roll-along, or optimum offset.

Field #3
This field shows the current instrument state while in acquisition mode. Possible states are:

No data There is no data in the stack memory, and the instrument is ready to arm. In this state all acquisition parameters can be changed.
<<< ARMED >>> The instrument is armed and ready for trig
<<< Pending arm >>> When multiple instruments are connected and synchronized, this state is activated when the user arms one instrument, and it awaits arm confirmation from the other instrument(s).
<<< Triggered >>> The instrument has triggered and data acquisition is proceeding.
Transferring data ... The data has been acquired to the channel memory and is being transferred to the stack memory.
Data in memory There is data in the stack memory, the instrument is ready to arm. Some, but not all, acquisition parameters can be changed.
<<<SAVING>>> Data is being saved. When the save operation has finished the stack memory will be cleared, the record updated, and the instrument ready to arm.
<<< Testing >>> The geophone test is active.
Geophone test data The stack memory contains geophone test data. Press <SAVE> to save the data, or <ESC> to reject.
Accept or reject? Waiting for the user to accept or reject the acquired data for stack in preview mode. Press <ENT> to accept, <ESC> to reject.
WARNING A minor error occurred, or an informational message ahs to be displayed. Details will be displayed in a separate message.
ERROR A fatal or major error occurred. Detailed information is displayed in a separate error message.

Field #4
This field displays the battery voltage.

Field #5
The field displays which, if any, reference channel that is active.

Basic operation

The preferred way of operating the SeisTW software is by using the built-in keyboard. However, it may be operated using any Linux compatible keyboard and mouse.

Start a measurement

To start a measurement, either press <ARM>, or select File->New (Ctrl+N). Selecting New opens a dialog where you can choose acquisition mode (Standard, Roll-along, or Optimum offset). For roll-along, you may also choose number of channels for each roll-along record.

Pressing <ARM> will open an acquisition record using the last active acquisition mode.

When an acquisition record has been created, you should verify the acquisition settings. The easiest way to access these, is to press:

Arming and Trigging

When all acquisition settings are set, press <ARM> to arm the instrument. The status bar will show the message "<<< ARMED >>>" (see Instrument states.

The instrument will trig according to the Trig Setup settings. When the instrument triggers, this is indicated in the centre field of the status bar, which will show a message "<<< Triggered >>>". When the data has been acquired, it is transferred from the channel memory to the stack memory. The actual behaviour depends on the active stack mode.

Save and Update

Press <SAVE> (or F3) when the acquisition of the current record is finished, to save the data. When the data has been saved, the stack memory is cleared, the layout parameters are updated, and the instrument will be ready for the next <ARM>.

It is possible to only save the data (without clearing the stack memory and updating the record) by pressing Ctrl+S (or File/Save, or selecting Save in the ).

Terraloc Mk6 Driver

Installation

The Terraloc Device Driver, terralocmk6driver.sys, is located the folder $(WINDIR)/System32/Drivers. The API, terraloc.dll, is located in the as the application intallation folder. It should be verified that the API and the Device Driver have indentical version numbers. This can be done by going to Help/About in the application. The About dialog will show the version numbers reported by the API and Device Driver.

The device driver handles all access to the instrument hardware. The API provides an interface for applications to communicate with the device driver.

Acquisition Modes

By pressing Ctrl+N, or selecting New under the Quick Menu, it is possible to select which acquisition mode to use. The following acquisition modes are available:

Standard

In this mode all acquisition is performed according to the current settings. The only automatic actions are clearing the stack memory and updating the record after a save & update operation.

Roll-along

When pressing first ARM, a new record is created containing the number of traces defined by the Roll-along start/end parameters in the Layout Geometry Dialog.
Pressing will cause the record to be saved and the roll-along parameters to be updated according to the Roll-long step size as defined in the Layout Geometry Dialog. How the roll-along parameters are updated is determined by the Roll-along reverse direction check box.

Optimum offset

When a record is created in the optimu offset acquisition mode, it will initially have only the first trace's stack enabled. Besides, only the currently active trace and traces containing data will be visible. When the data for the currentnly active trace has been acquired, the user can press <SAVE>, which will advance the active trace one trace. Pressing <SAVE> when the last trace is active will save & update the record.

It is still possible for the user to modify acquisition parameters, including receiver spread parameters, but be careful. Modifying receiver spread parameters, may lead to acquiring data on a trace that already contains data, but that should not be updated.

User Interface

Quick Menu


The Quick Menu is access by pressing Space. It contains the most important File commands.

Acquisition Setup



Sampling interval

The sample interval in microseconds. Available sample intervals are: 25, 50, 100, 250, 500, 1000, 2000 microseconds.

No of samples

Number of samples to acquire for each trace. Available choices: 128, 256, 512, 1024, 2048, 4096, 8192, 16384.

Pre-trig/delay

Selects the pre-trig or delay for the trig event. Pre-trig is set by entering a negative time, and will save the corresponding amount of data before the trig event. Delay is set by entering a positive time, and will delay data acquisition after the trig corresponding to the delay. The pre-trig/delay is measured in milliseconds. The pre-trig can be set from 1 ms to the record length. The delay can be set to the following ranges:


Sample interval
(microseconds)		 Delay range
(milliseconds)
25 0 - 819
50 0 - 3276
100 0 - 6553
250 0 - 16384
500 0 - 32768
1000 0 - 65536
2000 0 - 132072

No of stacks

If this number is greater than zero, the record will be saved automatically when this number of stacks has been acquired. When the record has been saved, the next record will be initialized.

Stack mode

The stack mode determines how the acquired data is added to the stack and how it is displayed. The following four stacking modes are available.

Fast stack

Adds the acquired data to the stack as soon as the data is available in the channel memory. Does not display the data. The instrument is automatically armed for the next shot.

Auto stack

The same as the Fast stack, but the stacked data is displayed. The instrument is automatically armed for the next shot.

Preview

Displays the acquired data and prompts the user to accept or reject the data. When the data is accepted, it is added to the stack, and the stacked data is displayed. Press <ENT> to accept, or <ESC> to reject, the acuiqred data. The instrument is automatically armed for the next shot.

Single stack

Same as Auto stack, but the instrument has to be manually armed again for the next shot.

Re-arm mode

If it is set to Auto, the instrument is automatically armed after a record has been saved. This is useful in, for example, marine surveys. If set to Manual the user has to arm the instrument nby pressing <ARM>, or some external arm source has to set the arm input to its armed state.

Trig Setup


Trig input mode

Selects trig input source, and its mode.

Analog

The instrument is triggered when the signal exceeds the trig level on the analog trig input.

Make/break

The instrument is triggered when a trigger cirquit is closed (make) or opened (break). The trigger cirquit can for example be a twisted pair of insulated wires inserted in a dynamite charge. The wires are then shorted when the charge explodes (make switch). A break switch can be a single wire, which has been wound a few turns around the charge and the explosion cuts the wire (break switch).


The instrument detects the state change from opened to closed (make), or fromclosed to opened (break), depending on the state at the time of arm.

TTL rising edge

The instrument is triggered when the TTL signal on the digital trig input goes from low to high.

TTL falling edge

The instrument is triggered when the TTL signal on the digital trig input goes from high to low.

Trig input level

The trig sensitivity level. It can be set from 0 to 100%.

External trig out mode

Can be set to Off, TTL Rising edge, or TTL falling edge. Determines what signal is output on the external trig output pin in the Aux connector when the instrument is triggered.

External arm out mode

Can be set to Off, TTL Rising edge, or TTL falling edge. Determines what signal is output on the external arm output pin in the Aux connector when the instrument is armed.

External arm in mode

Can be set to Off, TTL Rising edge, or TTL falling edge. Determines what signal received on the external arm input pin in the Aux connector will arm the instrument.

Ext. arm verify

When several instrument are interconnected, the external arm inputs and outputs can be connected in such a way that when one instrument is armed it in turn will arm the next instrument. If the choice is checked, when the user presses <ARM> on one instrument, it will wait until it receives an external arm from the last instrument in the chain before actually accept the arm event. If no external arm is received within the timeout set, the instrument will disarm, and the disarm event will propagate to all the other instruments.

Verify timeout

The time to wait for an external arm before disarming and showing an error message.

Noise Monitor Setup


Noise monitor status

Enable/disable the noise monitor. When it is enabled, it will be displayed while the instrument is armed.

Damping

Damping in decibels of the displayed signal. The maximum displayed signal level is always 120 dB, but the smallest level displayed can be set by changing the damping.

Threshold level

Sets a threshold level in decibels. When the monitored signal exceeds this threshold level, a warning is displayed in the noise monitor window.

Show noise

Pressing this button, will display the noise monitor until the user presses <ESC>. Pressing <SPACE> will activate the geophone test relays (a one second pulse). It is not possible to activate the geophone test relays while the instrument is armed.

Acquisition Filter Setup


Notch filter

Status

Enables/disables the notch filter. The notch filter is calibrated at factory for either 50 or 60 Hz. The calibrated value is stored in the system configuration.

Analog lowcut filter

Status

Enables/disables the analog lowcut filter.

Slope

Select the slope of the filter. Possible choices are 12 db/octave and 24 dB/octave.

Cutoff freq.

Selects the low cutoff (3 dB rejection) frequency in Hz. The possible frequency choices depends on the selected slope.


Cutoff freq (Hz)
12 dB/octave		 Cutoff freq (Hz)
24 dB/octave
1215
2430
3645
4860
6075
7290
84105
96120
108135
120150
132165
144180
156195
168210
180225
192240

Layout Geometry Dialog


Source location

X, Y, and Z co-ordinates of the source location.

Receiver locations

X, Y, and Z co-ordinates for the receivers. Press Space to access the Layout Helper Dialog, which can help you to enter the values quickly.

Pressing Ctrl+Down from the seconds row and down, will subtract the value in the cell on the previous row from the value in the cell on the selected row, and enter the difference in the cell on the next row and focus to this cell.

Move-ups

Describes how the source, receivers and the receiver connected to the reference channel (if any) are updated when a record has been finsihed.

Units

Defins the linear units used for all location data. Possible values are: None, Meters, Centimeters, Feet, Inches. If None is specified it will be up to the user to interpret location data.

Source type (*)

An appropriate text string describing the source used to acquire this record. Pre-defined values are: Untitled, Hammer, Weight_Drop, Seismic_Gun, Explosives, and Vibrator. The asterisk specifies that the user may enter any text string in this field.

Receiver type (*)

An appropriate text string describing the receivers used to acquire this record. Pre-defined values are: Untitled, Vertical_Geophone, SH_Horizontal_Geophone, SV_Horizontal_Geophone, and Accelerometer. The asterisk specifies that the user may enter any text string in this field.

Ref. channel

Selects if the reference channel connector is activated, and which channel that will be redirected to this connector. It is possible to re-direct either channel 12 or channel 24 to the reference channel connector. With more than 24 channels installed (i.e. typically 48 channels), it is channels 24 or channel 48 that can be redriected to this connector.

Roll-along

The settings used to control roll-along measurements (see Mode: Roll along). Note that it is assumed that the lowest numbered trace on the left side and the highest numbered on the right side.

If needed, the channels can be re-mapped as in any other acquisition mode.

Roll-along reverse direction

If checked, the roll-along segments will be shifted to the left (normally they are shifted to the right).

First trace

The first (left most) trace of the current cable layout for the current record.

Length

Number of traces comprising one roll-along segment.

Step size

Number of steps to shift the roll-along after finishing a record.

Layout Helper


The Layout helper dialog can be used to quickly fill in the receiver locations in the Layout geometry dialog. It is possible to enter values any two of the entries layout start, layout end, and receiver separation. The third entry is calculated automatically.

Pressing <Space> in a cell belonging to one of the above entries, causes this entry to become the one that is calculated automatically. Selecting <Ok> to exit from the dialog, causes the receiver locations grid to be fill out automatically.

Layout start

X, Y, and Z co-ordinates of the first receiver of the layout.

Layout end

X, Y, and Z co-ordinates of the last receiver of the layout.

Receiver separation

The receiver separation in x-, y-, and z-directions, respectively.

Receiver Spread Dialog


Channel

Specifies the channel mapped to each trace. It is possible to map any channel to any trace, and one channel can be mapped to any number of traces. If the reference channel is enabled, it will be mapped to the trace as specified by the corresponding channel.

Enter the channel number using the numeric keys.


Maps the channels in forward direction (ch. 1 to #1, ch. 2 to #2, etc.).
Maps the channels in reverse direction (ch. 12 to #1, ch. 23 to #2, etc.).

Polarity

Specifies the polarity of the recorded signal. If the polarity is positive, the signal will be stored as it is recorded. If the polarity is negative, the signal will be inverted before it is stored.


Toggles the value in the current cell.
Toggle the polarity of all traces.
Sets the current trace to positive polarity.
Sets the current trace to negative polarity.
Sets all traces to positive polarity.
Sets all traces to negative polarity.

Stack on

Enables/disables stacking for the specified trace. If the stack for a trace is disabled, data cannot be added (or subtracted) from that stack.


Toggles the state of the currently selected stack.
Toggles the states of all stacks.
Enables the currently selected stack.
Disables the currently selected stack.
Enables all stacks.
Disables all stacks.

Trace on

Enables/disables viewing of the specified trace.


Toggles the state of the currently selected trace.
Toggles the states of all traces.
Enables the currently selected trace.
Disables the currently selected trace.
Enables all traces.
Disables all traces.

Header Info Dialog


Job ID

A text string identifying the jib.

Line ID

A text string identifying the seismic line.

Client

A text string naming the client of the job.

Company

A text string namig the company of the client.

Observer

A text string namig the observer(s).

Note

A free form text string.

View Options


View mode

The view mode determines how data is scaled for the display.

Enhanced

The data is not scaled, but the amplitudes are used directly. It is, however, possible to attenuate the displayed signals using the enhanced attenuation parameter.

Normalize

The max value in each trace is used to scale all samples in the trace. See also global scaling.

AGC

Uses the average amplitude calculated from a running window (which length is specified by the AGC window parameter). This means that each sample is scaled according to the average signal level in the samples vicinity.

Hyperbolic

Applies a hyperbolic scaling to the data. If the logarithmic choice is selected, the function ArcSinH will be used, otherwise the function TanH is used.

Trace style

VAR+

This is a wiggle trace with the positive side filled-in.

VAR-

This is a wiggle trace with the negative side filled-in.

Wiggle

The trace is plotted as a wiggle.

Dotted

Each sample value is plotted as a dot.

Time compression

Selects compression in time. This makes more of the record visible. Available compressions: 1x, 2x, 4x, and 8x.

Scale factor

A general factor by which every sample is multiplied.

Trace clip

How many traces the plotted curve may overlap before it is clipped. With trace clip = 1, no overlap will occur. If trace clip is 2, a trace may overlap the positive part of the trace on the left, and the negative part of the trace on the right.

Remove DC offset

If enabled, the DC offset is removed before the trace is scaled. It is recommended to keep this enabled.

Show tic lines

Major and minor tic lines are plotted. The time interval between the tic lines is determined by sample interval and time compression.

Normalize

Global scaling

If enabled, the maximum value in the whole record is used to normalize every sample of all traces.

AGC

AGC window

The length of the window, in milliseconds, used to calculate the average value to use for scaling of a sample value. The window moves along the trace with each sample that is scaled.

Enhanced

Average

If enabled, the average values on the stack is used for each trace, otherwise the summed stack is used.

Attenuation

Used to attenuate the signals. This will bring out weker signals, while hiding stronger signals.

Hyperbolic

Logarithmic

If enabled, ArcSinH is used a scaling function, otherwise, TanH is used.

Linear range

This value sets the amplitude level that is within the linear part of the scaling function. Both scaling functions are linear in the beginning (for small amplitudes), while compressing larger amplitudes.

Frequency analysis

Windowing function

Selects function to be used for data windowing. Possible values are No window, Hanning, Hamming, Blackman, Bartlett, Kaiser, 4th order Blackman-Harris, Flat top.

Max frequency

The maximum frequency to display. The displayed spectrum will go from 0 Hz up to the selected maximum frequency. Possible values are

50, 100, 200, 500, 1000, 2000, 5000, 10000, 20000, 50000.

Dynamic range

The maximum frequency component is used as reference when calculating the spectrum. TThe dynamic range can be set to 6 dB up to 198 dB in 6 dB steps.

Velocity analyzer


The velocity analyzer can be used to estimate the apparent seismic velocity in refraction records. When the analyzer starts, it checks the receiver locations and calculates the receiver separation. If the receiver separation seems to be erroneous, or the receiver locations are not specified, the user can enter a valid separation value in the dialog at the top of the window.

Context menu


First breaks

Access the first breaks sub menu (see First breaks).

Velocity Analyzer

Activates the Velcoity analyzer.

FIR filter

Access the FIR filter dialog.

Moving average filter

Access the Moving average dialog.

Unfilter data

Discards any processing results and reads back the original data from disk.

Cross correlate

Performs cross correlation of the data.

View options

Access the View options menu.

About


The About dialog displays information about instrument, serial number software versions etc. The most important information is the API and Driver version numbers. These two numbers have to be identical.

Process

FIR Filter

Clicking on Ok will apply the filter to the current data.

Filter type

Selects the type of filter to apply to data. Available choices are Low pass, high pass, band pass, and band reject.

Windowing function

Data windowing function to apply to data when filtering. Available choices are Hanning and Blackman.

Cut-off frequencies

The cutoff frequencies are specified as the frequency where the passband signal has been reduced by 3 dB and the transition band starts. The low- and highpass filters only specifies a single cutoff frequency, while the bandpass and bandreject filters specifies two, low- and high cutoff frequencies.

Filter length

The number of filter coefficients used to realize the filter. The longer the filter, the steeper its slope, i.e. it will cut the signal more abrubtely. A longer filter also takes longer to apply, especially to long records.

Cross correlate


Selecting Cross correlate in the context menu, shows the Reference trace selection dialog. Enter the trace number that was used for the reference signal when doing a vibration seismic acquisition, and then press <Ok>. The cross correlation may take several minutes, so be patient.

Below are two figures showing a raw data from record acquired using vibration seismics, and then after corss correlation.

Raw data





After corss correlation.


First breaks

These entries are accessed via a sub menu in the Context menu.

Auto

Performs an automatic first break pick.

Clear

Clears the first break picks.

Save

Saves the first break picks to a text file in the current directory. There are two formats available, ABEM's fir-format, and REFLEXW's pck-format. Choose format when saving the first break picks.

Load

Loads the first break picks from a pick file to the currently active record. Ifthere are more picks in the pick file than traces in the record, the superfluous picks are discarded. If there are fewer picks, only the first traces loads the picks.

Moving average


Perform a moving average filtering of the current data. The user selects the number of samples to use when calculating the average.

Keyboard

General

The tables below does not describe usual meanings of the Terraloc keys. E.g. , key is only described when is has some special function (e.g. opens a context menu), and not that it generates a space-character when entering text.


Opens the Quick menu.
Navigates between fields in dialogs.
Navigates in reverse direction between fields in dialogs.
Opens the Preferences Dialog.
Saves the current file (prompting for overwrite is the file already exists).
Opens the Save As dialog.
Forces a save of the current file (overwriting any existing file).
Opens a context menu.
Shows/hides the logging window.
Shows/hides the Trace View and Frequency View.
Shows/hides the toolbar.
Opens the edit source/receivers dialog.
Opens the edit header info dialog.
Opens the Acquisition setup.
Opens the Trig setup.
Opens the Noise monitor setup.
Opens the Acquisition filter setup.
Opens the Receiver spread dialog.
Opens the Layout geometry dialog.
Opens the Header info dialog.
Opens the View Options dialog.

Acquisition mode

Arms the instrument.
Forces the instrument to trig.
If the current instrument state is No data, activates the geophone test and diaplys the geophone test data.
Deletes the last acquired shot (if the data is still in the channel memory).
Disarms an armed instrument.
Saves the current file (prompting for overwrite is the file already exists), clears the stack memory, and updates the reocrd.
Opens the Save As dialog, saves the data, clears the stack memory, and updates the reocrd.
Forces a save of the current file (overwriting any existing file), clears the stack memory, and updates the reocrd.

Record/Trace/Frequency View


Shifts the focus to the next view.
  • Record View: Move the trace marker to the right (at the end of the record it will wrap around to the beginning).
  • Trace View: Scrolls the trace to the right.
Move the trace marker to the left (at the beginning of the record it will wrap around to the end).
Scrolls the traces down a whole page.
Scrolls the traces up a whole page.
Scrolls the traces down.
Scrolls the traces up.
Moves the timeline down (increasing time). If you keep it pressed, the timeline movement will accelerate.
Moves the timeline up (decreaseing time). If you keep it pressed, the timeline movement will accelerate.
Moves the timeline down (increasing time) in large steps.
Moves the timeline up (decreaseing time) in large steps.
Set the first break for the trace selected by the trace marker at the position of the timeline.
Opens the Velocity Analyzer.



Moves the borders of the Trace view.

Velocity Analyzer


Select edit field in velocity analysis bar at top of page.
Moves the velocity marker down (increasing time).
Moves the velocity marker up (decreaseing time).
Moves velocity marker to the right
Moves velocity marker to the left
Moves the free end of the velocity marker down (increases the slope)
Moves the free end of the velocity marker up (decreases the slope)
Moves the free end of the velocity marker to the right.
Moves the free end of the velocity marker to the left.

Noise monitor

When the instrument is armed and the noise monitor enabled, all acquisition mode key inputs are valid.
Increases threshold level. Size of increase depends on amplitude scale of the noise monitor.
Decreases threshold level. Size of decrease depends on amplitude scale of the noise monitor.
When just monitoring the noise (instrument is not armed), pressing <Space< sends a test pulse to the geophones.
Increases the attenuation 6 dB.
Decreases the attenuation 6 dB.

Key mapping

The following table shows the mapping between the built-in keyboard and a PC-compatible keyboard. Only if a key combination, i.e. a key modified by shift or control, differ from the standard interpretation will it be presented in the table.

0
1
2
3
4
5
6
7
8
9
.
Esc


Backspace
Up
-
F2
Left
Tab
Right
F3
Shift
Down
+
F4
Ctrl
Space
F1
Enter
Delete