Sensors & Software pulseEKKO PRO User Manual
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Sensors & Software pulseEKKO PRO User Manual

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pulseEKKO PRO
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 Copyright 2005 Sensors & Software Inc.
2005-00040-01

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  • Page 1 PRO ’ UIDE  Copyright 2005 Sensors & Software Inc. 2005-00040-01...
  • Page 2 & S ENSORS OFTWARE RODUCT ICENCE OPYRIGHT IABILITY AND ARRANTY NFORMATION Important Please read this document carefully before removing the storage media from their protective cover SOFTWARE PRODUCT or assembling the . By removing the storage media or assembling the hardware, you are agreeing HARDWARE PRODUCT to be bound by the terms of this agreement.
  • Page 3 All statements, technical information, and recommendations related to SSI products are based on information believed to be reliable, but the accuracy or completeness is not guaranteed. Before using this product, you must evaluate it and determine if it is suitable for your intended application. You assume all risks and liability associated with such use. Any statements related to the product which are not contained in SSI current publications, or any contrary statements con- tained on your purchase order shall have not force or effect unless expressly agreed upon, in writing, by an authorized officer of SSI.
  • Page 4 Acknowledgement You acknowledge that you have read this agreement, understand it and agree to be bound by its terms and conditions. You further agree that this agreement is the complete and exclusive statement of agreement between the parties and supersedes all proposals or prior agreements oral or written between the parties relating to the subject matter of this agreement.

  • Page 5: Table Of Contents

    2.4.3.3 Connecting the Odometer Cable to the Control Module ........19 2.4.3.4 Connecting the Transducer Cables ...................20 Adding Accessories ............20 2.5.1 Electrical Beeper/Trigger Unit .............20 2.5.2 Fibre Optic Beeper/Trigger Unit ..................23 2.5.3 DVL Carrier ..................23 2.5.4 Odometers ....................24 2.5.5 ............25 Starting the pulseEKKO PRO System...
  • Page 6 Table of Contents pulseEKKO PRO .........25 2.6.1 Powering the DVL and Control Module ....26 2.6.2 Powering the Low Frequency Transmitter and Receiver ..............26 2.6.3 Digital Video Logger ..................27 2.6.4 Main Menu ............30 2.6.5 Using the Software Menus System Setup Parameters ..............31...
  • Page 7 PRO Table of Contents ............49 3.3.5.2 Set Odometer Manually ...............49 3.3.5.3 Odometer Direction .................49 3.3.6 Fibre Optic Testing ..................50 Survey Parameters ..................50 3.4.1 Start Position .................50 3.4.2 Antenna Step Size ................50 3.4.3 Positional Units ..............51 3.4.4 Data Directory Number ...................51...
  • Page 8 Table of Contents pulseEKKO PRO ...............73 5.4.2 Fiducial Markers for GPS ..............73 Data Collection Pause Menu ....................73 5.5.1 Exit ..................73 5.5.2 Continue ....................73 5.5.3 Scale .............75 5.5.4 Calib - Velocity Calibration ..............75 5.5.4.1 Hyperbola Matching ............77 5.5.4.2 Identifying Air Reflections ............78...
  • Page 9 PRO Table of Contents ................93 6.12.1 Borehole GPR ...........94 6.12.2 Walls, Pillars and Monument Surveys Troubleshooting ..................95 .....................96 Power Supply ......96 7.1.1 DVL and Control Module Power Requirements ..........97 7.1.2 Transducer Power Requirements ......97 7.1.3 Transmitter and Receiver Power Requirements ........98...
  • Page 10 Table of Contents pulseEKKO PRO Helpful Hints ....................117 ....................117 10.1 Batteries ..................117 10.2 Measuring Position ....................117 10.3 Data Files ......................117 10.4 Spares Appendix A: Data File Formats ..............A-1 Appendix B: GPR Signal Processing Artifacts ........B-1 Appendix C: Excerpts from the HP Fiber Optic Handbook ....

  • Page 11: Overview

    PRO 1-Overview Overview This manual describes how to set up and run a pulseEKKO PRO LF (low frequency) Ground Penetrating Radar (GPR) system connected to a Digital Video Logger (DVL) for data display and storage. System Assembly Section 2 System Assembly and Startup on page 2 details the &...

  • Page 12: System Assembly And Startup

    System Assembly and Startup System Configurations The modular design of the pulseEKKO PRO GPR makes the system very flexible and readily field-portable in a number of configurations. This section details the steps for assembling the Low Frequency Hand Held (Figure 2-1) and High Frequency Hand Towed (Figure 2-2) configurations.

  • Page 13: High Frequency Hand Towed

    The control module is attached to the back of the DVL. The transducers are connected to the control module via the transducer cables (Figure 2-2). Figure 2-2: The complete high frequency pulseEKKO PRO tow mode assembly.

  • Page 14: Dvl And Control Module

    2-System Assembly and Startup pulseEKKO PRO DVL and Control Module The DVL and Control Module are common to all configurations. 2.2.1 Attaching the Control Module to the DVL The control module unit must be attached to the back of the DVL (Figure 2-3). This may already have been done at the factory.

  • Page 15: Attaching The Fibre Optic Converters For Low Frequency Antennas

    PRO 2-System Assembly and Startup Figure 2-5: Attach the control module to the DVL using the 4 screws supplied (left) and a Phillips screwdriver (not supplied). Tighten the 37 pin connectors into place (right) with a small slotted screwdriver (not supplied).

  • Page 16: Low Frequency Transmitter, Receiver And Antenna Assembly

    (Section 3.2.1: P34). Figure 2-7: Low frequency, unshielded, bistatic antennas available for the pulseEKKO PRO. The antennas come in pairs; one transmitting antenna and one receiving antenna. The shortest antennas, the 200 MHz, are 0.5 metres long while the longest, the 12.5 MHz are 8 metres long.

  • Page 17: Attaching The Sockets To The Transmitter And Receiver

    PRO 2-System Assembly and Startup 2.3.2 Attaching the Sockets to the Transmitter and Receiver Insert and tighten the two female brass antenna sockets into the bottom of the transmitter and receiver electronic boxes (Figure 2-8). Tighten the sockets finger-tight. DO NOT APPLY UNDUE FORCE! Figure 2-8: Hand tighten the brass sockets into the bottom of the transmitter and receiver.

  • Page 18: Attaching The Mounting Blocks To The Antennas

    2-System Assembly and Startup pulseEKKO PRO 2.3.4 Attaching the Mounting Blocks to the Antennas Attach the antenna mounting blocks to the antennas by using the flathead screwdriver to tighten the 4 (four) quarter-turn fasteners, ensuring that the male brass antenna pins protrude up the center holes of the mounting blocks (Figure 2-10).

  • Page 19: Latching The Transmitter And Receiver To The Mounting Blocks

    PRO 2-System Assembly and Startup 2.3.5 Latching the Transmitter and Receiver to the Mounting Blocks Carefully place the transmitter and receiver electronic boxes down onto the mounting blocks such that both brass pins fully connect (Figure 2-11 Left). Then use the 2 plastic draw latch connectors to hold the electronics boxes onto the mounting block (Figure 2-11 Right).

  • Page 20: Inserting Batteries Into The Transmitter And Receiver

    2-System Assembly and Startup pulseEKKO PRO 2.3.6 Inserting Batteries into the Transmitter and Receiver With the transmitter and receiver power switched OFF, unlatch the 2 battery covers on the sides of the electronics and open (Figure 2-12). Place one 12-volt battery on each side on the electronics boxes making sure the positive (+) terminal faces inward toward the electronics (Figure 2-13).

  • Page 21: Attaching Handles

    PRO 2-System Assembly and Startup 2.3.7 Attaching Handles 2.3.7.1 Attaching the Adjustable Handles Attach the adjustable handle to the antenna using the flat head screwdriver to tighten the 4 quarter-turn fasteners as with the mounting block (Figure 2-14). This handle can then be adjusted for height by loosening the 2 levers by hand, moving the handle to the desired height and retightening the levers (Figure 2-15).

  • Page 22: Connecting The Fibre Optic Cables

    The next step is to connect the transmitter and receiver to the control module. a) The pulseEKKO PRO low frequency system uses 2 dual fibre optic cables like the one shown in Figure 2-16. These cables should be tested periodically (Section 7.2: P99) and inspected for kinks or signs of damage and repaired if necessary (Section 9.6: P113).
  • Page 23 PRO 2-System Assembly and Startup d) After attaching the dual fibre optic cables to the transmitter and receiver, the other end of the fibre optic cables are attached to the fibre optic converters on the control module (Figure 2- 18).

  • Page 24: High Frequency Transducer Assembly

    Frequency, Section 3.2.1: P34) Figure 2-19: High frequency, shielded, bistatic antennas available for the pulseEKKO PRO. The antennas come in pairs, one transmitting transducer and one receiving transducer. These are indicated by an “T” and “R” on the labels. The 1000 MHz trans- ducers are 14.5 cm (6 in) across, the 500 MHz transducers are 22.5 cm (9 in) across and the 250 MHz transducers are 38 cm (15...

  • Page 25: Mounting Transducers To The Skid Plate

    PRO 2-System Assembly and Startup 2.4.2 Mounting Transducers to the Skid Plate Skid plates are sized to fit a pair of transducers positioned side by side. Figure 2-20: Mounting the transducers onto the skid plate. The skid plate assembly consists of the bottom piece and two side flanges (top).

  • Page 26: High Frequency Hand-Towed System

    2-System Assembly and Startup pulseEKKO PRO 2.4.3 High Frequency Hand-Towed System One method of deploying the high frequency antennas is the Hand-towed configuration that includes the adjustable tow handle and an odometer. This section details the assembly of this configuration.

  • Page 27: Attaching The Big Wheel Odometer

    PRO 2-System Assembly and Startup 2.4.3.2 Attaching the Big Wheel Odometer Figure 2-22: The big wheel odometer. Ensure that the small yellow odometer is tightly pressed against the rim of the wheel so that it spins when the big wheel is rotated.

  • Page 28: Connecting The Odometer Cable To The Control Module

    2-System Assembly and Startup pulseEKKO PRO 2.4.3.3 Connecting the Odometer Cable to the Control Module The Big Wheel Odometer comes with a long cable that extension to allow it to connect to receptacle 1 on the control module (Figure 2-24). The Big Wheel Odometer and odometer cable can be seen in the complete system configuration (See Figure 2-2 on page 3).

  • Page 29: Connecting The Transducer Cables

    PRO 2-System Assembly and Startup 2.4.3.4 Connecting the Transducer Cables The next step is to connect the transducers to the control module. Figure 2-25: Connecting the transducer cables to the transducers. The connections are secured with latches. Figure 2-26: Connecting the transducer cables to the Control Module. The transducer cable from the transmitting transducer connects to the control module receptacle labelled 4 while the transducer cable from the receiving transducer connects to the con- trol module receptacle labelled 5.

  • Page 30: Adding Accessories

    To attach the Fibre Optic unit to the pulseEKKO PRO handles, insert the end of the hand screw through the hole in the adjustable handle attached to the transmitting antenna and tighten it into the unit (Figure 2-28).
  • Page 31 Output (grey) receptacle on the transmitter. This connection enables the beeper part of the remote beeper/trigger unit to work. Note that if you have a pulseEKKO 100 transmitter (Section 3.2.8: P41) you cannot use the pulseEKKO PRO fibre optic beeper/trigger.
  • Page 32 2-System Assembly and Startup pulseEKKO PRO Figure 2-29: Fibre optic cabling details for the Fibre Optic Remote Beeper/Trigger unit. The Fibre Optic Remote Beeper/Trigger unit is powered by one 9 Volt battery that slides into the battery compartment (Figure 2-30). Please note the proper polarity of the battery. An alkaline 9V battery will normally power the unit for 3-5 hours of heavy use so it is a good idea to have spare 9 Volt batteries available.

  • Page 33: Dvl Carrier

    2.5.4 Odometers The pulseEKKO PRO system can accept an odometer input to trigger the system to acquire data at equal distance intervals (Step Sizes). An odometer eliminates the necessity of using a tape measure or survey...

  • Page 34: Gps

    The odometer has an electrical connection to receptacle 1 on the control module (Figure 2-32). Figure 2-32: The pulseEKKO PRO accepts input from various odometers including the wheel odometer shown in the figure, which is typically used with the SmartCart. Odometers attach to receptacle 1 on the control module.

  • Page 35: Starting The Pulseekko Pro System

    PRO 2-System Assembly and Startup Starting the pulseEKKO PRO System 2.6.1 Powering the DVL and Control Module Connect the Control Module to Power Supply Cable to the receptacle labelled 3 on the control module (Figure 2-34) This cable will only fit on the number 3 receptacle. Note that the other end of this cable has an XLR connector.

  • Page 36: Powering The Low Frequency Transmitter And Receiver

    2-System Assembly and Startup pulseEKKO PRO 2.6.2 Powering the Low Frequency Transmitter and Receiver Turn the transmitter and receiver ON by pressing the button on the top of each unit. The red Power LED on the top of the unit will flash 5 times and then stay on to indicate the unit is ready for operation. If not, check that the batteries inside the Transmitter and Receiver are fully charged and have been inserted the right way.

  • Page 37: Main Menu

    36). There is also a flow chart of the complete menu system on the DVL shown in Figure 2-37. Figure 2-36: pulseEKKO PRO main menu screen on the DVL. To begin acquiring data, press button number 1 for Run pulseEKKO GPR. Details about data collection are given in Section 4 on page 65.
  • Page 38 2-System Assembly and Startup pulseEKKO PRO The DVL can be shut down by pressing button number 5. Exit also serves an important function. Before exiting, the program saves all the current parameters. This process enables the system to start up with the same settings as before it was last powered off.
  • Page 39 1 Set DVL Time & Date 2 Set DVL Transfer Mode 3 Set DVl into Upgrade Mode 4 Select Display Info Mode 8 Return 6 View Complete Setup 8 Return Figure 2-37: Flow chart of the complete pulseEKKO PRO DVL menu system.

  • Page 40: Using The Software Menus

    2-System Assembly and Startup pulseEKKO PRO 2.6.5 Using the Software Menus Menu items can be selected in one of two ways: 1) If the menu item has a number listed beside it, that item can be selected by pressing the corresponding button number on the DVL.

  • Page 41: System Setup Parameters

    Selecting View Complete Setup from this menu or View Setup from the main menu (See Figure 2-36 on page 27) displays all the current parameter settings for the pulseEKKO PRO system. A screen display similar to the one in Figure 3-2 will be seen: Figure 3-2: The View Setup option displays all the current settings and indicates which System Setup headings to select to change individual parameters.

  • Page 42: System Parameters For A Quick Start To Data Collection

    3-System Setup Parameters pulseEKKO PRO Figure 3-2 illustrates how many parameters must be set before data collection can start. While intimidating, many of the parameters can use the default values while many others are rarely changed at all. System Parameters for a Quick Start to Data Collection...

  • Page 43: Gpr Parameters

    PRO 3-System Setup Parameters GPR Parameters Selecting the GPR Parameters menu option will display a screen similar to Figure 3-3. This section describes, in detail, each parameter listed in this menu. Figure 3-3: The GPR System Parameters menu. Use the Up and Down buttons to move to the desired parameter and edit the value by pressing the A and B buttons.

  • Page 44: Antenna Frequency

    3-System Setup Parameters pulseEKKO PRO 3.2.1 Antenna Frequency Deciding which antenna frequency to use for a survey depends on the objectives of the survey. As frequency decreases the depth of investigation generally increases but spatial resolution decreases. Therefore, the ideal survey will be one that uses the highest frequency that adequately penetrates to the target depth.

  • Page 45: Time Window

    PRO 3-System Setup Parameters 3.2.2 Time Window The Time Window setting determines how long (and therefore how deep) the radar system will probe the subsurface. It is important that it is set to a value appropriate for the depth of the survey target. An entire survey could fail if the window is not sufficiently long enough to sample to the depth of the target.

  • Page 46: Temporal Sampling Interval

    (Section 3.2.6: P39). 3.2.3 Temporal Sampling Interval The pulseEKKO PRO system samples the GPR signals returning to the receiver. The resulting GPR data is a series of numbers that represent signal amplitude at equally spaced time intervals. The time interval between points on the trace is called the Temporal Sampling Interval.

  • Page 47: Antenna Separation

    PRO 3-System Setup Parameters 3.2.4 Antenna Separation As the transmitting and receiving antennas are moved along a survey line, it is important that a separation be maintained between them. When the antennas are mounted on a cart the antenna separation is fixed, but when the antennas are not fixed in position, it is common to use a rope or measuring tape to maintain the proper separation (See Figure 6-4 on page 84).

  • Page 48: Antenna Step Size

    3-System Setup Parameters pulseEKKO PRO 3.2.5 Antenna Step Size This specifies the distance the antenna pair will be moved each time to collect a new trace during a Reflection mode survey (Section 3.4.5: P51). To properly resolve subsurface targets spatially, it is important that a proper Antenna Step Size be selected.

  • Page 49: Radar Velocity

    PRO 3-System Setup Parameters 3.2.6 Radar Velocity If an accurate depth axis on the real-time display is desired, or the user wishes to see the approximate depth of penetration while setting the time window value (Section 3.2.2: P35), the user should supply the program with the average radar wave propagation velocity (in m/ns or ft/ns).

  • Page 50: System Stacking

    3-System Setup Parameters pulseEKKO PRO 3.2.7 System Stacking In noisy environments, one way of improving signal to noise is to collect more than one trace at each survey position, averaging them and recording the averaged trace. This is known as “trace stacking” or “stacking”.

  • Page 51: Pulser Setting

    Volt transmitter will be set to 400 Volts and a 1000 Volt transmitter will be set to 1000 Volts. The only time that PRO Auto is not the correct setting for a pulseEKKO PRO transmitter is if you have a 400 to 1000 variable voltage transmitter and you want to set the pulser voltage to a value lower than 1000 Volts.

  • Page 52: Acquisition Control

    3-System Setup Parameters pulseEKKO PRO Acquisition Control Selecting the Acquisition Control parameters menu option from the System Setup main menu (See Figure 3-1 on page 31), will display a screen similar to Figure 3-5. This section details each parameter listed in this menu.

  • Page 53: Triggers

    PRO 3-System Setup Parameters 3.3.1.1 Triggers Triggering the system with an electrical, Fibre Optic or DVL B Button trigger (options 1 -3) is best for surveying in difficult terrain where antennas cannot be moved easily or at regular time intervals. For the position of each measurement point, the system assumes the operator has moved the antennas one step size along the survey line.

  • Page 54: Free Run Trace Delay

    3-System Setup Parameters pulseEKKO PRO 3.3.3 Free Run Trace Delay When the system is run in Free-Run mode (Section 3.3.1.3: P43), this option allows the user can specify a time delay (in seconds) between traces. This delay allows time for the user to set up the antennas at the new position.

  • Page 55: Gps Recording Mode

    PRO 3-System Setup Parameters The DVL can be set up to read and log GPS information collected during data acquisition with the GPR system. GPS information can be logged in two different ways: 1) For every trace collected by the GPR system, or 2) Every time the user adds a fiducial to the data by pressing the Fiducial button or the A button (Section 5.4: P72).
  • Page 56 3-System Setup Parameters pulseEKKO PRO Trace #85 $GPGGA,134850.00,4338.204868,N,07938.429003,W,2,06,2.1,152.60,M,-35.09,M,4.2,0118*74 $GPVTG,152.6,T,,,002.3,N,004.3,K,D*43 $GPGSA,A,3,30,26,10,13,24,06,,,,,,,4.2,2.1,3.7*37 $GPGGA,134850.00,4338.204868,N,07938.429003,W,2,06,2.1,152.60,M,-35.09,M,4.2,0118*74 $GPVTG,152.6,T,,,002.3,N,004.3,K,D*43 $GPGSA,A,3,30,26,10,13,24,06,,,,,,,4.2,2.1,3.7*37 Trace #86 $GPGGA,134851.00,4338.204362,N,07938.428362,W,2,06,2.1,152.40,M,-35.09,M,5.2,0118*72 $GPVTG,136.9,T,,,002.8,N,005.2,K,D*45 $GPGSA,A,3,30,26,10,13,24,06,,,,,,,4.2,2.1,3.7*37 On a Tag mode means that whenever a fiducial marker (F1, F2 etc.) is added to the data by pressing the Fiducial button or the A button on the DVL (Section 5.4: P72), a data string of GPS information will be added to a file.

  • Page 57: Baud Rate

    PRO 3-System Setup Parameters $GPGSA,A,3,04,30,10,13,24,06,,,,,,,3.2,2.4,2.1*32 $GPGGA,134301.00,4338.192559,N,07938.449176,W,2,06,2.4,153.17,M,-35.09,M,5.0,0118*7A $GPVTG,314.4,T,,,000.6,N,001.1,K,D*41 $GPGSA,A,3,04,30,10,13,24,06,,,,,,,3.2,2.4,2.1*32 3.3.4.2 Baud Rate The baud rate is the speed that data is sent from the GPS receiver to the serial port of the DVL. The available options are: 2400, 4800, 9600 (default) or 19200. Often, the baud rate for GPS units is 4800. If you are having a problem getting the GPS to work with the DVL, the Baud Rate is the most likely problem.

  • Page 58: Test Gps With Listing

    3-System Setup Parameters pulseEKKO PRO 3.3.4.7 Test GPS with Listing After all the settings above have been input and the GPS receiver is attached to the serial port on the DVL, the test option allows the user to check that the DVL is receiving the GPS output.

  • Page 59: Set Odometer Manually

    PRO 3-System Setup Parameters 3.3.5.2 Set Odometer Manually When Odometer Calibration is selected, the user is prompted to manually enter the odometer calibration factor. In general, this method of odometer calibration is not recommended because it will not be as accurate as calibrating the odometer over a known distance.

  • Page 60: Survey Parameters

    3-System Setup Parameters pulseEKKO PRO Survey Parameters Selecting the Survey Parameters menu option from the System Setup main menu (See Figure 3-1 on page 31), will display a screen similar to Figure 3-8. This section details each parameter listed in this menu.

  • Page 61: Data Directory Number

    PRO 3-System Setup Parameters 3.4.4 Data Directory Number This option is used to determine the directory that the data files will be saved to. The idea is that related data files are saved in the same directory. The Data Directory Number can be changed in this menu or under the Run pulseEKKO menu (Section 5.1: P69).
  • Page 62 3-System Setup Parameters pulseEKKO PRO X Lines Only Set up a first-quadrant XY grid. Data lines run in the X direction, distance increasing from the Y axis baseline. Line numbers increase in the positive Y direction (see Figure 3-9). Lines must be equally spaced.
  • Page 63 PRO 3-System Setup Parameters Y Lines Only Set up a first-quadrant XY grid. Data lines run in the Y direction, distance increasing from the X axis baseline. Line numbers increase in the positive X direction (see Figure 3-10). Lines must be equally spaced.
  • Page 64 3-System Setup Parameters pulseEKKO PRO X and Y Lines Set up a first-quadrant XY grid. X data lines run in the X direction, distance increasing from the Y axis baseline. Line numbers increase in the positive Y direction (see Figure 3-11). Lines must be equally spaced.

  • Page 65: Line Spacing

    PRO 3-System Setup Parameters 3.4.7 X Line Spacing For X Only or XY grid data acquisition, the distance between the X survey lines needs to be specified in this menu (Figure 3-9 and Figure 3-11). The distance units are assumed to be the same as those specified in Positional Units (Section 3.4.3: P50)

  • Page 66: Display Parameters

    3-System Setup Parameters pulseEKKO PRO Display Parameters Selecting the Display Parameters menu option from the System Setup main menu (See Figure 3-1 on page 31), will display a screen similar to Figure 3-12. This section details each parameter listed in this menu.
  • Page 67 PRO 3-System Setup Parameters Figure 3-13: Grey scale traces depict the signal amplitude as shades of grey from white to black. Data traces can be plotted to the screen with a width of 1 pixel (top left), 2 pixels (top right), 4 pixels (bottom left) or 8 pixels (bottom right). The narrower the trace width, the more data that can be plotted on one screen.

  • Page 68: Gain Type Applied And Gain Applied

    3-System Setup Parameters pulseEKKO PRO 3.5.2 Gain Type Applied and Gain Applied Since the radar signal strength normally decreases with increasing time, it is usually necessary to apply some sort of gain function to boost the weaker signals at later times.
  • Page 69 PRO 3-System Setup Parameters Figure 3-16: Shows how the AGC function (middle) is inversely related to reflector strength of the raw trace (top). The AGC gained trace (bottom) is a result of multiplying each point in the raw trace with the equivalent point in the AGC function.

  • Page 70: Sec Gain

    3-System Setup Parameters pulseEKKO PRO 3.5.2.2 SEC Gain The SEC (Spreading & Exponential Compensation) gain is a composite of a linear time gain and an exponential time gain. This gain compensates for the spherical spreading losses and the exponential dissipation of energy in the data being collected. Since radar data is attenuated exponentially and the SEC is an exponential gain (Figure 3-18), it tends to be the gain closest to physical reality.

  • Page 71: Constant Gain

    PRO 3-System Setup Parameters Figure 3-20: Display of a data section over buried tanks. An SEC gain was applied before plotting. The only user variable for the SEC gain is the Alpha Gain Applied value. This quantity represents the radar wave attenuation given in decibels/metre.
  • Page 72 3-System Setup Parameters pulseEKKO PRO Figure 3-21: Display of a data section over buried tanks. A Constant gain was applied before plotting.

  • Page 73: Dvl Setup Menu

    PRO 3-System Setup Parameters DVL Setup Menu 3.6.1 Set DVL Time and Date The date and time are saved with the data files. The DVL date and time setting can be changed by moving to one or more of the appropriate fields and editing the current setting. The LEFT and RIGHT arrows are used to move between fields.

  • Page 74: Select Display Info Mode

    PRO (See Figure 3-2 on page 31). Return Selecting Return will exit the System Setup menus and return the user to the pulseEKKO PRO main menu screen (see Section 2.6.4 on page 27). Exit also serves an important function. Before exiting, the program saves all the current data collection parameters.

  • Page 75: Running In Scope Mode

    PRO 4-Running in Scope Mode Running in Scope Mode Once the System Setup parameters have been set, data collection can begin by selecting 1 - Run pulseEKKO GPR from the main menu. The screen shown in Figure 4-1 will be visible.

  • Page 76: Scope Screen

    4-Running in Scope Mode pulseEKKO PRO Scope Screen A sample of a screen data plot while in Scope mode is shown in Figure 4-2. The radar amplitude (in millivolts) is plotted in the vertical axis while the time axis is plotted in the horizontal axis. The length of the time axis depends on the Time Window value.
  • Page 77 PRO 4-Running in Scope Mode Figure 4-3: Timezero or the first break is the first large deflection in the trace. Ideally, timezero needs to be shifted to the start of the second vertical division as shown in Figure 4-2. Use the Auto <> button to try and automatically locate timezero and set it to the correct position.

  • Page 78: Data Collection

    4-Running in Scope Mode pulseEKKO PRO Shift > and Shift < are used if the transmit pulse is visible on the screen but needs to be moved into the ideal region (Figure 4-3). The Shift button will change to reverse video when selected and the pulse will step across the screen in the direction indicated.

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